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Pharmacology Exam 1/3

Chapter 1

  • Pharmacology: the study of medicines

  • Drugs have three uses

    • Therapeutic

    • Preventative

    • Diagnostic

  • Pharmacognosy: the study of the natural origin of drugs and the effects of natural drugs

  • Hypocrites first proposed that disease was due to natural causes as opposed to some gods

  • Galen said that there is both a cause and a cure when someone gets sick

  • Asia is commonly about preventative medicine

  • Paracelsus supported the use of individual drugs

  • Valerious Cordis published dispensaries in Germany

  • Types of Herbal Medicine

    • preventative

    • folk

    • problematic

  • Homeopathy: body heals thyself

  • Genetic engineering: artificially ‘cutting’ and ‘splicing’ DNA into an organism’s DNA

    • Generally used for recombinant DNA technology

    • Used in agriculture, medicine, reproduction

Drug Categories

Prescription RX

  • Must be ordered by a licensed practitioner

Over the Counter

  • Can be sold by retail outlets/pharmacies

  • No prescription required

Narcotic/controlled

  • Must be ordered by a licensed practitioner

  • Many rules and regulations

Health Canada

  • To help Canadians maintain and improve their health

  • Promotes well being of Canadians

  • Policies and Procedures re:

    • Safe and nutritious food

  • Keep people informed e.g health threats

Regulations

Drug Approval Process

  1. Develop substance​

  2. Isolate & Purify Substance​

  3. Administer tissue cultures/small animals​

  4. Lab & Animal Studies​

  5. Clinical Trials​

  6. Evidence submitted to TPD​

  7. Drug Review by TPD​

  8. Risk/Benefits weighed​

  9. Marketing authorization granted or denied​

    After Approval

  • Distributors must report

    • Info about serious s/e​

    • Info re failure to produce effects​

    • New safety info

  • TPD monitors (therapeutic product directorate)

    • adverse events

    • investigations complaints

    • maintains post-approved surveillance

    • manages recalls

  • Special Access Program

    • Administered by TPD

    • specified MD

      specified patient (quandary care)

Chapter 2

Drug actions

  • Homeostasis: the stability of the organism

    • Achieved by control and feedback mechanisms

Homeostasis

  • Messengers and receptors

    • Messenger produced by cell → Messenger sent into extracellular fluid → Messenger reaches target cell → messenger binds with a receptor on the cell surface → effect produced

    • Specificity: the property of a receptor site that enables it to bind to a specific chemical messenger

    • Affinity: the strength by which a particular messenger binds to the receptor site

Mechanisms of drug action

  • Agonist: a drug that triggers the same response as an endogenous chemical messenger

    • Enhances the natural reaction to the messenger

  • Antagonist: a drug that blocks the action of an endogenous chemical messenger

    • Inhibits natural reaction

    • When they block action they may…

      • Directly inactivate the receptor

      • Bind to the receptor in a competitive fashion

  • Agonists stimulate receptors

  • Antagonists block receptors

Pharmacokinetics

  • Pharmacokinetics: the study of the activity of a drug within the body over some time

  • A-absorption

    • the process by which a drug enters the circulatory system

    • typically orally; disintegrate then release the drug into the GI tract for dissolution

factors affecting absorption

impact & example consideration route

considerations

route of administration

affects the drug’s systematic effects e.g oral, iv, the transdermal

oral route provides systemic absorption. IV skips absorption. Transdermal is a slow and steady

dosage form

affects rate due to form e.g. coated tablets disintegration tablets coated

coated tablets take longer. oral tablets instantly dissolve in saliva

  • D- distribution

  • M- metabolism

  • E- elimination

Chapter 5-Topical Medications

Integumentary System

  • The tissue that covers the body including skin, nails, and hair

  • Protects the body from exposure to harmful pathogens and harsh substances

  • Helps regulate body temperature

  • Skin

    • the body’s largest organ

    • 3 layers

      • Epidermis

      • Dermis

      • Subcutaneous tissue

  • Epidermis

    • Top layer

    • Forms new cells and sheds old, dead cells​

    • Produces nails, hair, glands​

    • Interspersed with melanocytes- the color of your skin

  • Dermis

    • Second layer

    • Composed of connective tissue, capillaries, and nerves​

    • Location of sebaceous glands (waxy substance) and sweat glands

  • Subcutaneous tissue

    • Third layer

    • Connects dermis to underlying organs and tissues

Sun Exposure and Skin Cancer

  • Ultraviolet A radiation damages the skin

    • UVA 1&2- suntan region

  • Ultraviolet B

    • burn

  • Characteristics of effective sunscreen

    • SPF of >30

    • protect against UVA and UVB

  • types of cancer

    • Actinic keratosis​

    • Basal cell carcinoma​

    • Melanoma​

    • Squamous cell carcinoma

  • Intrinsic aging

    • Loss of collagen and elastin in the dermis​

    • Less oil production​

    • Shrinking of subcutaneous tissue​

    • Thinning and sagging of skin​

    • A natural process that can be delayed but not stopped ​

  • Extrinsic aging

    • Caused by external factors such as sun exposure, air pollutants, smoking, skin irritation​

    • Lesions caused by external factors, genetic predisposition, or a combination of both​

    • DNA mutation resulting in benign tumors, precancerous conditions, skin cancer​

  • ABCDEs of skin cancer

    • Asymmetry

    • Border

    • Color

    • Diameter

    • Evolution

Drug Regimens and Treatments

  • Sunscreens

    • partially block UV radiation

    • Many reduce UVB rays whiles allowing UVA rays through.​

    • A common ingredient is PABA

      • para amino benzoic acid

  • Sun Protection Factor

    • Estimates how much longer a person can be in the sun and not burn​

    • Measures mostly UVB-blocking activity; therefore, a person may still get exposed to UVA radiation

medication

Therapeutic uses

cautions and considerations

Benzocaine (Lanacane)
Lidocaine (Xylocaine,
Solarcaine)

Relieve sunburn
pain temporarily

Associated with
methemoglobinemia, not
recommended in patients
< 2 years old

Hydrocortisone (Cortaid,
Cortizone)

decreases
inflammation,
accelerates healing,
relieves pain

Risk of allergic contact
dermatitis and local
sensitization

Silver sulfadiazine
(Flamazine, SSD)

Prevents infection in
serious burns.

Caution in sulfonamide
allergy, the potential for tissue
necrosis does not protect
against fungal organisms

  • Photosensitivity

    • Increased sensitivity of the eyes and skin to light​

    • Risk increases with drugs in certain classes​

    • Watch for computer prompts and warn patients to avoid sun exposure.

    • Classes of drugs include ACE inhibitors, antibiotics ((doxycycline, tetracycline, ciprofloxacin, ofloxacin, levofloxacin, sulfonamides), antidepressants(phenothiazines), antihistamines, antipsychotics, cardiovascular drugs(statins, enalapril, diltiazem), chemotherapeutic agents, diuretics( furosemide, hydrochlorothiazide), hypoglycemic(glipizide, glyburide), NSAIDs(Ibuprofen, ketoprofen, naproxen, celecoxib)

Define

  • integumentary: skin, hair, nails,

  • dermatology- the branch of medicine concerned with the diagnosis and treatment of skin disorders.

  • keratolytic-a type of medical treatment to remove warts, calluses and other lesions in which the epidermis produces excess skin.

  • astringent- contraction, closes your pours

  • antiseptic-prevents the growth of organisms/ diseases

  • antibiotic- medication inhibits or stops the growth

  • antipruritic- anti itching

  • emollient- help soften or soothe the skin

  • Demulcent​- relieves the inflammation on the skin​

  • Disinfectant​-a chemical that destroys bacteria

  • Bactericidal​- capable of killing bacteria

  • Bacteriostatic​- inhibits the growth of bacteria

  • Debridement​- removing damaged tissue and foreign objects from a wound

  • Granulation- healing of a serious wound

Acne, Wrinkles, Rosacea

  • Acne: overproduction of sebum is often caused by hormonal changes

    • Pimples,

    • blackheads,

    • whiteheads,

    • deep cysts in serious cases

  • Wrinkle

    • line or crease in the skin

    • promoted by sun exposure, smoking, lighter skin, heredity

  • Rosacea: chronic inflammatory disorder is seen in adults

    • redness, visible surface blood vessels, raised bumps

    • face only

    • excess sebum production

    • triggered by stress, temperature, hot drinks, exercise, spicy food, alcohol, products which irritate the skin, sunlight

Drug Therapy for acne, wrinkles, and rosacea

  • acne

    • cleanse twice a day

    • OTC products

    • topical prescription products

    • oral prescription products

  • Wrinkles

    • retinoids

  • Rosacea

    • identify and avoid triggers

    • topical agents

    • antibiotics

  • dermatitis

    • pruritis, inflamed skin that can be caused by a variety of factors

    • symptoms include areas of redness, dry flaky skin, raised or bumpy skins pruritis

psoriasis

  • an immunologic condition

  • manifests as well-defined plaques that are raised, silvery or white

  • can appear anywhere on the body and may be very small or quite large

  • exacerbated by stress and environmental factors

Topical Corticosteroids

  • anti-inflammatories

  • cortisone; steroids

  • for many types of skin

  • many forms

  • potency (fluorinated=stronger)

  • Rx and OTC

  • end in “sone” and “olone”

Hair Loss

  • androgenic alopecia

    • referred to as male-pattern baldness

    • affects men and women

    • hair follicles shrink, producing finer hair

  • Alopecia areata

    • a chronic inflammatory condition affecting hair follicles

    • may cause areas of complete hair loss

Antihistamines

  • inhibit inflammation, redness, and itching

  • work if histamine is released

  • antipruritic

  • Combination: Caladryl (calamine + diphenhydramine)

Skin Infections

  • bacterial infections

    • impetigo

      • caused by S. aureus or Streptococcus

      • superficial, highly contagious; common in an early childhood

    • erysipelas- don’t worry about

      • A form of cellulitis that spreads rapidly through the skin

    • folliculitis

      • Inflammation of a hair follicle, surrounding tissue not affected

    • Furuncle

      • Begins in a sebaceous gland and associated hair follicle; more extensive and deep than folliculitis

    • Carbuncle

      • a coalescent mass of infected follicles; deeper than a furnicle

  • Fungal infection

    • candidiasis

      • Caused by Candida albicans; lesions in the vagina and mouth

    • ringworm

      • caused by a microscopic fungus

      • infects the skin or nails

      • spreads outward as the center heals, leaving a ring

Yeast Infection

  • cause: candida albicans

  • treated the same as fungal infections

Fungal Skin Infections

  • ringworm (tinea corporis)

  • athlete’s foot (tinea pedis ic)

  • jock itch (tinea crudis)

  • nails (onychomycosis)

Viral infections

  • Herpes simplex virus (HSV

    • HSV type 1 associated with cold sores

    • HSV type 2 associated with genital infection

  • Herpes Zoster

    • Chicken Pox (Vaccine- varicella – Varivax)

    • Shingles ( Vaccine – varicella life and non-live –Zostavax and Shingrix)

    • Wart

    • The epidermal tumor is caused by a virus

    • Viruses may lie dormant and later cause reinfection

    • Topical Salicylic acid preparations, i.e Compound W, Duoplant

External Parasites

human lice

  • wingless parasitic insects that feed on human blood

  • spread by direct contact with infested person’s head, body, or personal items

  • symptoms of infestation is itching

types

description

body lice
(pediculosis
corporis)

-Live on clothing and moist areas of the body
-Treated by removing clothing, bathing patient,
putting on clean bedding and clothes

Head lice
(pediculosis
capitis)

-Lives on scalp and hair-Feed on blood from the scalp which produces itching
-Female louse has a life span of 40 days, lays 10
nits/day
- Nits stick to hair close to the scalp and hatch in 8 days.
- Nits are seen by shining a bright light on the scalp
- Nits are white and cannot be shaken off.

Pubic lice
(pediculosis
pubis

-Live in the pubic area
- Infection may resemble dermatitis and be itchy.
- Transmitted by sexual contact 2

types of lice:

  • body lice

    • Shower or bathe, and apply 20-30g of cream or lotion to the whole body; then wash off in 24 hours

    • repeat once a week

  • head lice

    • Massage two ounces of less of cream or lotion into premoistened hair for four minutes, and rinse out

    • repeat once a week

  • pubic lice

    • Apply a thin layer of cream or lotion that extends to the thighs, trunk, and axillary regions; wash off in 24 hours.

    • repeat once a week

Scabies

  • type of mite

  • Female burrows in epidermis secretes substances that disintegrate the skin, then feeds on the skin

  • Intense itching at night caused by increased activity of mitese, feeding, and deposition of feces.

  • Lesions are slightly elevated, wavy grayish-white burrows.

  • Lesions often seen in webs between fingers

Drug Therapy for Scabies

  • permethrin

    • adults

      • apply to the skin from neck to feet

    • infants and older adults

      • apply to the scalp and face

    • everyone

      • wash off 8-12 hours later

  • Crotamiton (Eurax)

    • cream for the intense itching

Antiseptics and Disinfectants

  • Use of Disinfectants

    • instruments

      • Best to use two separate agents with different mechanisms of action

    • treats infections in the mouth and on the body

      • The oral cavity is difficult to disinfect because very few drugs adhere to the mucosal lining long enough to overcome bacteria

Types of Disinfectants

  • Povidone-iodine (Betadine)- wounds

  • Zinc oxide (Desitin)- diaper rash

  • Chlorhexidine gluconate (Peridex, Perichlor, Periogard)- antibacterial dental rinse

Decubitus Ulcers

Are caused by contact pressure applied to the area of the skin. It happens when patients are confined to beds or wheelchairs. The skin is meant to skin if not the skin will become thin. It is common near bony areas such as the tailbone, heels, hips, spine, and elbows. How to prevent it? Turn patients in every 2 hours. Apply for skin protection. Using air beds. Ensure good hydration and nutrition.

Treatments for Ulcers

  • debridement

    • Removes dead, crusted, or contaminated tissue around a wound to promote healing

    • can be painful so pain medication is given prior

  • Positioning

    • Reposition bedridden patients every 2 hours

    • Prevents new wounds from developing

    • Prevents existing wounds from getting worse

    • 24-hour care is required if they are unable to move independently

Burns

  • causes

    • heat and thermal injury

    • electrical and chemical sources

  • determinants of prognosis

    • severity

      • how deep the damage is

    • % of body surface affected

      • Determined by dividing the body into major sections

Drug Regimens and Treatments for Burns

  • cooling and cleaning

    • cool water

    • A mixture of refrigerated and room-temperature saline

    • Water-soaked gauze pads cooled in the refrigerator

  • Blisters

    • not to be drained or popped

Drug Regimens and Treatments for Burns:
Silver Sulfadiazine

Protects non-superficial wounds from bacterial infection. Side effects are skin discoloration, skin rash, and a burning sensation. Contraindications are pregnancy and infants under 2 months. Cautions and considerations would be allergies Careful wound care and monitoring of tissue necrosis

Burns and Skin Ulcers

  • mechanism for healing

    • debridement

    • granulation

    • drainage

  • debridement

    • dead tissue is removed

    • new tissue forms at the base

  • Granulation

    • when the lumpy, pink tissue containing new connective tissue and capillaries form around the edges of a wound

  • Drainage

Other Drugs

  • drugs to absorb exudates

    • Duoderm

  • Drug for debridement

    • collagenase (Santyl)

  • Drugs for granulation

    • polyurethane foam dressing (eg, Allevyn)

Complementary and Alternative Therapies

  • aloe gel

    • Has wound-healing, antibacterial, and antifungal properties

    • In concentrated form, used for treating mild psoriasis and burn-wound healing

    • Needs to be applied three times a day for up to four weeks

    • Concentrations in many lotions and oils are not sufficient to do more than moisturize

  • Clove Oil

    • An antiseptic used on exposed dentin when combined with zinc oxide or zinc acetate

  • Lanolin, Cocoa Butter, Vegetable or Seed Oils

    • Added as moisturizers to creams and lotions

    • Keep skin hydrated and soft

  • Vitamins A, D, and E

  • Emollients added to moisturizers to promote skin health and healing

Chapter 16

The Immune System, Bacterial Infections, Fungal Infections, and Drug Therapy

Anatomy and Physiology of the Immune System

  • The immune system helps the body fight infection

  • Organs of the immune system and their functions

    • The bone marrow produces white blood cells which
      fight infection.

    • The thymus produces T lymphocytes.

    • The lymph nodes trap microbes, and the lymph vessels carry the fluid of the lymphatic system to cleanse body tissues.

    • The spleen removes microbes from the blood.

  • Immune System

    • bodies built-in defense mechanisms against pathogens

    • made of specialized cells, tissues, and organs

cells of the Immune System

  • leukocytes: white blood cells

    • agranulocytes: don’t contain granules in the cytoplasm

    • Granulocytes: contain granulates in the cytoplasm

      • Monocytes: circulate in the blood; move into infected tissue

        • macrophages: mature; ingest invaders

        • lymphocytes: detect specific pathogens; support immunity

  • Types of immunity

    • innate immunity

      • present from birth

      • first line of defense that is quick to fight pathogens

      • forms of innate immunity

        • integumentary and GI system, which forms a barrier between the body’s interior and outside pathogens

        • Phagocytic leukocytes, which break down pathogens

          • Eosinophils, leukocytes, neutrophils

          • The complement system, which consists of enzymes and proteins

            • histamine, leukotrienes, prostaglandins

Infectious Diseases

  • define

    • Disorders caused by pathogenic organisms such as bacteria, viruses, fungi, or protozoa

  • Infectious Disease Prevention

    • handwashing

      • using soap and water to wash hands

    • hand hygiene

      • Cleaning hands using alcohol-based products that do not require water

    • Universal precautions

      • Personal safety standards to protect against accidental exposure to pathogens

      • Includes personal protective equipment

      • Sanitizing

Bacterial Infections

  • Bacteria: single-celled organisms

    • can be found on the skin, in the mouth, in the gastrointestinal tract

    • cause disease when they grow uncontrollably or enter the bloodstream

  • Pathogenic bacteria: can cause an infection

  • Bacterial Infection: bacterial growth in body tissues can cause tissue damage

    • symptoms of bacterial infection

      • Fever of >101 degrees Fahrenheit and white blood cell count of >12,000/mm^3

Characteristics

Description

oxygen requirement

-aerobic bacteria need oxygen to live--anaerobic bacteria can survive without oxygen

bacterial shape

-cocci are spherical-bacilli are rod-shaped-spirochetes are spiral-shaped arrangement

arrangement

clusters, repair thickness

the thickness of cell walls

- Gram-positive bacteria have a thick cell wall that absorbs crystal violet- gram-negative bacteria have a thin cell wall that does not absorb crystal violet

Antibiotic Selection

  • antibiotic: a chemical substance with the ability to kill or inhibit bacterial growth

  • factors considered in an antibiotic selection

    • type of pathogen suspected

    • antibiotic’s spectrum of activity

    • location of the pathogen

  • identifying bacteria and selecting a drug treatment

    • sample or swab taken is taken from the parties

    • the sample is grown in a laboratory culture

    • culture and sensitivity tests performed

  • a broad spectrum is effective against multiple organisms

  • Empirical treatment: using medication to treat a patient before the specific microorganism causing the infection is identified

  • nosocomial infection: acquired while a patient is in a hospital or nursing home

  • bactericidal agent kills the invading agent

  • bacteriostatic agent: inhibits the growth of bacteria

  • clinical and microbiologic responses are used to evaluate the outcome

Antibiotic Side Effects and Dispensing Issues

  • Parenteral antibiotics should be mixed exactly as directed

    • drug may cause adverse effects if not done correctly

  • The counting tray should be swabbed with alcohol after counting oral antibiotics

  • most antibiotics are taken on an empty stomach, but some should be taken with food

  • Antibiotics may decrease the effectiveness of birth control pills

  • Antibiotics should be given around the clock

Antimicrobial Resistance

  • antibiotic resistance: is the ability of bacteria to develop defense mechanisms that resist or inactivate antibiotics used

  • preventing resistance

    • prescribing antibiotics only when necessary

    • using auxiliary labels that remind patients to complete the entire course of antibiotics

Storage and Liquid Antibiotics

  • storage requirement

    • some antibiotics must be refrigerated

    • some antibiotics may be stored at room temperature

    • technicians may discuss this information with the patient

  • Medication Flavors

    • technicians may suggest and change flavors

    • the flavored medication increases adherence in children

Ophthalmic Antibiotics

  • manufacturing requirements

    • same pH as the eye

    • sterility

  • Dispensing Issues

    • often rejected due to expense

    • need to inform the prescriber of alternatives

STIs and Drug Treatment

  • Sexually Transmitted Infections: genital-system infections transmitted by sexual activity

  • They were formally known as STDs and general diseases

  • preventing STIs

    • no sex

    • wait until marriage

    • use a condom

  • Chlamydia

    • caused by chlamydia trachomatis

    • often asymptomatic

    • typically occurs with gonorrhea

    • potential for reinfection if a partner is not treated

  • Gonorrhea

    • caused by Neisseria gonorrhoeae

    • Symptoms: painful urination and discharge of pus from the penis, abdominal pain due to pelvic inflammatory disease

    • Long-term complications include sterility in patients with a penis.

    • Risk of systemic infections in any patient if untreated

    • Occurs frequently with chlamydia

  • Syphilis

stages

Description

primary-stage infection

-chancre at the site of infection which heals in weeks-fluid from chancre highly infectious-if not treated, will progress to the secondary stage

secondary-stage Infection

-skin rash, patchy hair loss, malaise, mild fever-symptoms subside, the disease becomes latent

Late or tertiary-stage infection

-occurs after at least 10 years-rubbery tissue masses in organs and deafness, blindness, CNS lesions, perforation of the roof of the mouth

  • Other Sexually Transmitted Infections

infection

description

nongonococcal urethritis

-Caused by catheters, chemical agents, or sexual transmission-Genital discharge, burning while urinating, itching-May progress to PID in patients with a uterus, cervix, fallopian tubes, or ovaries

Gardnerella vaginitis

-Characterized by vaginal discharge and odor-Caused by an interaction between the organism and anaerobic bacteria in the vagina-Frothy discharge, fishy odor, vaginal pH of 5 to 6

trichomonas vaginalis

-Bacteria found in individuals of any sex-Potential for infection if vaginal acidity is disturbed-Profuse, yellowish, or light cream-colored discharge with a disagreeable odor that irritates, burning, and itching

  • Medications and their use

medication

infection

azithromycin

certain stages of syphilis, gonococcal infections

ceftriaxone

penicillinase-producing bacteria

doxycycline

lymphogranuloma venereum, which is caused by chlamydia trachomatis

metronidazole

Gardnerella, vaginalis

tetracycline and erythromycin

chlamydia

penicillin G benzathine

syphilis, especially during the primary stage

Fungi and Diseases

  • fungus: Single-celled eukaryotic organism

    • mushrooms, yeasts, mold

  • They are different from green plants since they lack chlorophyll and reproduce using spores

  • They are different from animal cells and bacteria by having rigid cell walls

  • they are different from human cells since human cell membranes contain cholesterol and fungi’s cell membranes contain ergosterol

  • Infectious Disease Treatment

    • Fungal Infections

      • Dermatophytes are fungal infections of the skin

      • Candidiasis causes vaginal yeast infections and oral thrush

      • not all fungi cause infections

        • states of immunodeficiency

        • drug therapy

        • poor nutrition

        • IV catheters

        • Some cancers

        • Human immunodeficiency virus

Antifungal medication polyenes azoles, echinocandins, misc

drug regimens and treatment for fungal infections: antifungal drugs

Fighting Parasitic and Protozoal Infections

  • Infectious Disease Treatment

    • parasitic and protozoal infections

      • Parasites are organisms that live off a host

      • protozoa are single-celled organisms that usually cause infections through oral-fecal route

      • Giardiasis is an intestinal infection caused by protozoa and is carried in bird droppings, deposited in water or on vegetation

Common Parasitic and Protozoan Organisms and Infections

  • Therapy often combines 2 or 3 drugs

    • quinine

    • hydroxychloroquine-Plaquenil

    • doxycycline

    • tetracycline

    • clindamycin

    • atovaquone- Malarone

    • Mefloquine-Lariam

Complementary and Alternative Therapies

  • echinacea: used to treat the common cold, RTIs, and vaginal yeast infections

    • reduces the severity and length of symptoms

    • variable concentrations in the products availably

    • no standard dose established

    • must be used multiple times a day and started at the first signs of infections

  • Zinc

    • used to enhance wound healing and prevent wound-associated infections

    • no well-established dose

  • Garlic: used for immune system stimulation and prevention of infections

    • used topically for dermatophyte infections

    • side effect of oral garlic dermatitis or burns

    • drug interaction for garlic: anticoagulants

  • Ginseng: used for several conditions including prevention of infection

    • has been shown to reduce the length of cold sores and the risk of recurrence

    • side effects are headaches

    • drug interaction with ginseng: warfarin

  • Vitamin C: used to boost the immune system and for its antioxidant effects

    • side effects of high doses are diarrhea, upset stomach, kidney stones

Immune System, Viral Infections, and Drug Therapy

17.1 Viruses and Viral Infections

Virus

  • an infectious agent smaller than a bacterium, not a whole-cell organism

  • Individuality consists virus particle is a virion

  • Consists of a core of DNA or RNA surrounded by a capsid

  • must attach itself to a host cell to replicate

Ways that viruses spread

  • direct contact, ingestion of contaminated food or water, inhalation of airborne particles, exposure to contaminated body fluids or equipment

Viruses and Viral Infections

  • virus

    • a minute infectious agent smaller than a bacterium

    • consists of segments of DNA or RNA surrounded by a protein coating or capsule

    • requires host cells to reproduce

Stages of Viral Infection

  1. Attachment: Virion attaches to cell receptors

  2. Penetration: virion penetrates the cell and escaped into the cytoplasm

  3. uncoating: virion sheds capsid and presents DNA or RNA to the cell nucleus

  4. Replication and Assembly: Virion DNA or RNA causes cells to produce new viral particles

  5. release: duplicated viruses are released from the host cell

Significant Viral Infection

  • Influenza: symptoms include malaise, myalgia, headache, chills, fever

    • Patients at risk for complications include the elderly; patients with cardiovascular disease, renal disease, diabetes, and respiratory conditions; immunocompromised patients.

    • Annual vaccinations are recommended for those at risk for complications.

  • Hepatitis: inflammation of the liver

    • various types referred to as hepatitis A through G

    • severity range from benign to serious

  • HIV: considered a chronic disease

    • regimens of at least three drugs

    • important to monitor for drug interactions

Classification of Viral Infections

  • Viral Duration and Severity

    • An acute viral infection quickly resolves.

    • Chronic viral infection has a long course with periods of remission.

    • A slow viral infection maintains a progressive course over months or years.

  • The extent of Viral Infection

    • A local viral infection affects tissues of a single system.

    • A generalized viral infection has spread to other tissues.

  • Latent Viruses

    • A virus that lies dormant
      after infection and then later becomes active

    • Examples: herpesviruses
      and HIV

Virus and Host-Cell Interaction

  • Immunoglobin

    • A type of antibody produced by host cell B lymphocytes

    • An immunoglobulin that matches a viral protein may prevent the virus from attaching to a cell or may destroy the virus.

  • Interferon

    • Induces production of proteins that may disrupt viral replication or prevent spread to uninfected cells

  • Vaccination

    • description

      • Exposing a patient to a component of a virus or an altered viral strain to produce antibodies

      • When later exposed to the actual virus, the infection does not develop because natural defenses have been primed.

    • Viral Mutations

      • It makes effective vaccine production difficult.

      • An example is the influenza vaccine which must be reformulated each year

Chapter 17.2 Antiviral Agents (Nonretroviral)

  • challenges of treating viral infection

    • Viruses use host’s cellular processes to function and replicate.

    • Medications which block the virus life cycle are often toxic to the patient.

    • The similar challenge presented by chemotherapy agents for cancer

  • Antiviral Drugs

    • formulated to seek out a virus and prevent its replication without interfering with normal host function

Therapeutic Uses of Antiviral Drugs

  • Herpesvirus Infections

    • Herpes Simplex 1 (HSV-1)

    • Herpes Simplex 2 (HSV-2)

    • Varicella-zoster (chicken pox/ shingles)

    • cytomegalovirus (human herpesvirus 5)

  • Influenza

  • Respiratory Syncytial Virus (RSV)

Antiherpes Agents

  • Work Wise: Ganciclovir and Valganciclovir are considered hazardous drugs, so it is essential to follow handling precautions as outlined in the pharmacy’s workplace policies and procedures

Anti-Influenza Agents

Other Antiviral Agents

HIV/AIDS and Antiretroviral

  • Define

    • retrovirus: uses RNA as its genetic material

    • Reverse transcriptase: The enzyme retroviruses use to become part of the host’s DNA

    • Human immunodeficiency virus (HIV): A retrovirus that attaches to receptors on the surface of CD4 cells

      • It uses reverse transcriptase to convert its genetic material from RNA to DNA

    • Acquired Immunodeficiency Syndrome (ADIS): Syndrome which occurs when patients have advanced and severe forms of
      HIV

      • You can have HIV without having aids.

  • Antiretroviral drugs

    • difficult to tolerate due to side effects and drug interactions

    • Can be combined in a “cocktail” that attacks viral replication in multiple stages

    • must be taken chronically

    • some cocktails available as a single tablet

  • NRIs and NtRTIs

    • They inhibit reverse transcriptase, which prevents the formation of a DNA copy of viral RNA

    • Class Side Effects are nausea, diarrhea, and abdominal pain which improves in the first few weeks. More permanent effects are lactic acidosis with hepatic steatosis

NRITs and NtRTIs

NNRTIs

  • Protease Inhibitors

    • work by decreasing the formation of the protease enzyme, which cleaves specific HIV protein precursors necessary for the construction of new infectious virions

    • Typically combined with other HIV drugs; metabolized through cytochrome P-450 resulting in many drug interactions which are sometimes severe; not to be used with statins;

    • Side effects include redistribution of body fat, facial atrophy, breast enlargement, hyperglycemia, hyperlipidemia, the possibility of increased bleeding episodes in patients with hemophilia.

Protease Inhibitors

Fusion Inhibitors

  • Chemokine Coreceptor Antagonist

    • medication is maraviroc (Celestin)

    • It works by preventing HIV from attaching and entering immune cells.

    • special characteristic is that it has to be given with other antiretroviral drugs

    • Side effects of Chemokine Coreceptor Antagonists include cough, abdominal pain, dizziness, fever.

    • risk for hepatotoxicity with allergic features monitor closely for infection

Integrase Inhibitors

  • Responding to Exposure to HIV

    • Healthcare worker risks

      • exposure to blood and other bodily fluids

      • needlestick injuries

    • Postexposure Prophylaxis

    • can be decreased the risk of infection by 80% should start treatment with 2 hours

  • Combining antiretroviral medications

    • advantage

      • improve adherence

    • disadvantage

      • fixed doses unsuitable for unstable patients

    • examples

      • Lamivudine-zidovudine (Combivir)

      • Elvitegravir-cobicistat-emtricitabine-tenofovir (Stribild)

      • Emtricitabine-tenofovir (Truvada)

Immunization

  • Immunity is resistance to an infectious disease.

  • Immunization: the process whereby a person acquires immunity or resistance to an infectious disease

  • Methods of acquiring immunity:

    • Passive Immunity: antibodies transferred to an individual

      • occurs naturally during pregnancy

      • happens artificially during administration of immunoglobulin

    • Active Immunity: individual makes their own antibodies

      • naturally through exposure to pathogens

      • artificially through vaccines

  • Purpose is to prevent viral infections by providing immunity

  • exposes a patient to a component of a virus or altered viral strain

  • development of antibodies specific to the virus

  • patient’s defenses primes for subsequent exposure

  • viral mutations

    • patient’s defenses do not recognize mutated virus since they were primed against the original virus

    • example is influenza which is redone yearly

  • A vaccine induces the body to make antibodies which recognize the virus antigen and fight infection

  • Live Attenuated Vaccines: use live but weakened pathogens to induce an immune response

  • Inactivated Vaccines: use pathogens that have been killed

  • Immunization Schedule

    • Schedule source: adult and childhood vaccination schedules are published by the CDC

    • vaccines for children: most lead to a lifetime immunity

      • boosters given for continued protection

    • vaccines for healthcare workers: hepatitis B vaccination and annual influenza vaccine often required by employers

CDC recommended immunizations

  • Common Vaccines

    • Travel Vaccines

      • Recommended when traveling from areas of low infection rates to areas of high infection rates

      • Given two or more weeks before travel to give the immune system time to mount sufficient response

      • Travel clinics may be located in clinics or pharmacies and provide immunizations and advice about what vaccines are necessary

    • Dosage Forms and Administration

      • Most require storage in refrigerator or freezer, storage temperatures strictly followed

      • If warmed to room temperature must be used right away

      • Not to be refrigerated again if warmed to room temperature

      • Must be used within minutes to hours once reconstituted

      • Advance mixing of vaccines not recommended

      • Vaccines not to be mixed in same syringe with other medications

    • Cautions and considerations

      • Patients to receive vaccine information sheet (VIS) and sign a consent form as required by law.

      • Healthcare personnel trained in vaccine administration must be trained in CPR

  • Complementary and Alternative Therapy

    • Andrographis

      • May reduce symptom severity and duration of influenza if started within 36 to 48 hours

        • Side effects include chest discomfort, headache, nausea, rash.

        • May interact with anticoagulants, blood pressure medications, and immunosuppressants

      • Colloidal silver

        • Used topically and orally for infection

        • Side effects include argyria, neurologic deficits, kidney damage.

      • Elderberry

      • May be used for influenza when initiated within 48 hours of symptoms

      • Oscillococcinum


MJ

Pharmacology Exam 1/3

Chapter 1

  • Pharmacology: the study of medicines

  • Drugs have three uses

    • Therapeutic

    • Preventative

    • Diagnostic

  • Pharmacognosy: the study of the natural origin of drugs and the effects of natural drugs

  • Hypocrites first proposed that disease was due to natural causes as opposed to some gods

  • Galen said that there is both a cause and a cure when someone gets sick

  • Asia is commonly about preventative medicine

  • Paracelsus supported the use of individual drugs

  • Valerious Cordis published dispensaries in Germany

  • Types of Herbal Medicine

    • preventative

    • folk

    • problematic

  • Homeopathy: body heals thyself

  • Genetic engineering: artificially ‘cutting’ and ‘splicing’ DNA into an organism’s DNA

    • Generally used for recombinant DNA technology

    • Used in agriculture, medicine, reproduction

Drug Categories

Prescription RX

  • Must be ordered by a licensed practitioner

Over the Counter

  • Can be sold by retail outlets/pharmacies

  • No prescription required

Narcotic/controlled

  • Must be ordered by a licensed practitioner

  • Many rules and regulations

Health Canada

  • To help Canadians maintain and improve their health

  • Promotes well being of Canadians

  • Policies and Procedures re:

    • Safe and nutritious food

  • Keep people informed e.g health threats

Regulations

Drug Approval Process

  1. Develop substance​

  2. Isolate & Purify Substance​

  3. Administer tissue cultures/small animals​

  4. Lab & Animal Studies​

  5. Clinical Trials​

  6. Evidence submitted to TPD​

  7. Drug Review by TPD​

  8. Risk/Benefits weighed​

  9. Marketing authorization granted or denied​

    After Approval

  • Distributors must report

    • Info about serious s/e​

    • Info re failure to produce effects​

    • New safety info

  • TPD monitors (therapeutic product directorate)

    • adverse events

    • investigations complaints

    • maintains post-approved surveillance

    • manages recalls

  • Special Access Program

    • Administered by TPD

    • specified MD

      specified patient (quandary care)

Chapter 2

Drug actions

  • Homeostasis: the stability of the organism

    • Achieved by control and feedback mechanisms

Homeostasis

  • Messengers and receptors

    • Messenger produced by cell → Messenger sent into extracellular fluid → Messenger reaches target cell → messenger binds with a receptor on the cell surface → effect produced

    • Specificity: the property of a receptor site that enables it to bind to a specific chemical messenger

    • Affinity: the strength by which a particular messenger binds to the receptor site

Mechanisms of drug action

  • Agonist: a drug that triggers the same response as an endogenous chemical messenger

    • Enhances the natural reaction to the messenger

  • Antagonist: a drug that blocks the action of an endogenous chemical messenger

    • Inhibits natural reaction

    • When they block action they may…

      • Directly inactivate the receptor

      • Bind to the receptor in a competitive fashion

  • Agonists stimulate receptors

  • Antagonists block receptors

Pharmacokinetics

  • Pharmacokinetics: the study of the activity of a drug within the body over some time

  • A-absorption

    • the process by which a drug enters the circulatory system

    • typically orally; disintegrate then release the drug into the GI tract for dissolution

factors affecting absorption

impact & example consideration route

considerations

route of administration

affects the drug’s systematic effects e.g oral, iv, the transdermal

oral route provides systemic absorption. IV skips absorption. Transdermal is a slow and steady

dosage form

affects rate due to form e.g. coated tablets disintegration tablets coated

coated tablets take longer. oral tablets instantly dissolve in saliva

  • D- distribution

  • M- metabolism

  • E- elimination

Chapter 5-Topical Medications

Integumentary System

  • The tissue that covers the body including skin, nails, and hair

  • Protects the body from exposure to harmful pathogens and harsh substances

  • Helps regulate body temperature

  • Skin

    • the body’s largest organ

    • 3 layers

      • Epidermis

      • Dermis

      • Subcutaneous tissue

  • Epidermis

    • Top layer

    • Forms new cells and sheds old, dead cells​

    • Produces nails, hair, glands​

    • Interspersed with melanocytes- the color of your skin

  • Dermis

    • Second layer

    • Composed of connective tissue, capillaries, and nerves​

    • Location of sebaceous glands (waxy substance) and sweat glands

  • Subcutaneous tissue

    • Third layer

    • Connects dermis to underlying organs and tissues

Sun Exposure and Skin Cancer

  • Ultraviolet A radiation damages the skin

    • UVA 1&2- suntan region

  • Ultraviolet B

    • burn

  • Characteristics of effective sunscreen

    • SPF of >30

    • protect against UVA and UVB

  • types of cancer

    • Actinic keratosis​

    • Basal cell carcinoma​

    • Melanoma​

    • Squamous cell carcinoma

  • Intrinsic aging

    • Loss of collagen and elastin in the dermis​

    • Less oil production​

    • Shrinking of subcutaneous tissue​

    • Thinning and sagging of skin​

    • A natural process that can be delayed but not stopped ​

  • Extrinsic aging

    • Caused by external factors such as sun exposure, air pollutants, smoking, skin irritation​

    • Lesions caused by external factors, genetic predisposition, or a combination of both​

    • DNA mutation resulting in benign tumors, precancerous conditions, skin cancer​

  • ABCDEs of skin cancer

    • Asymmetry

    • Border

    • Color

    • Diameter

    • Evolution

Drug Regimens and Treatments

  • Sunscreens

    • partially block UV radiation

    • Many reduce UVB rays whiles allowing UVA rays through.​

    • A common ingredient is PABA

      • para amino benzoic acid

  • Sun Protection Factor

    • Estimates how much longer a person can be in the sun and not burn​

    • Measures mostly UVB-blocking activity; therefore, a person may still get exposed to UVA radiation

medication

Therapeutic uses

cautions and considerations

Benzocaine (Lanacane)
Lidocaine (Xylocaine,
Solarcaine)

Relieve sunburn
pain temporarily

Associated with
methemoglobinemia, not
recommended in patients
< 2 years old

Hydrocortisone (Cortaid,
Cortizone)

decreases
inflammation,
accelerates healing,
relieves pain

Risk of allergic contact
dermatitis and local
sensitization

Silver sulfadiazine
(Flamazine, SSD)

Prevents infection in
serious burns.

Caution in sulfonamide
allergy, the potential for tissue
necrosis does not protect
against fungal organisms

  • Photosensitivity

    • Increased sensitivity of the eyes and skin to light​

    • Risk increases with drugs in certain classes​

    • Watch for computer prompts and warn patients to avoid sun exposure.

    • Classes of drugs include ACE inhibitors, antibiotics ((doxycycline, tetracycline, ciprofloxacin, ofloxacin, levofloxacin, sulfonamides), antidepressants(phenothiazines), antihistamines, antipsychotics, cardiovascular drugs(statins, enalapril, diltiazem), chemotherapeutic agents, diuretics( furosemide, hydrochlorothiazide), hypoglycemic(glipizide, glyburide), NSAIDs(Ibuprofen, ketoprofen, naproxen, celecoxib)

Define

  • integumentary: skin, hair, nails,

  • dermatology- the branch of medicine concerned with the diagnosis and treatment of skin disorders.

  • keratolytic-a type of medical treatment to remove warts, calluses and other lesions in which the epidermis produces excess skin.

  • astringent- contraction, closes your pours

  • antiseptic-prevents the growth of organisms/ diseases

  • antibiotic- medication inhibits or stops the growth

  • antipruritic- anti itching

  • emollient- help soften or soothe the skin

  • Demulcent​- relieves the inflammation on the skin​

  • Disinfectant​-a chemical that destroys bacteria

  • Bactericidal​- capable of killing bacteria

  • Bacteriostatic​- inhibits the growth of bacteria

  • Debridement​- removing damaged tissue and foreign objects from a wound

  • Granulation- healing of a serious wound

Acne, Wrinkles, Rosacea

  • Acne: overproduction of sebum is often caused by hormonal changes

    • Pimples,

    • blackheads,

    • whiteheads,

    • deep cysts in serious cases

  • Wrinkle

    • line or crease in the skin

    • promoted by sun exposure, smoking, lighter skin, heredity

  • Rosacea: chronic inflammatory disorder is seen in adults

    • redness, visible surface blood vessels, raised bumps

    • face only

    • excess sebum production

    • triggered by stress, temperature, hot drinks, exercise, spicy food, alcohol, products which irritate the skin, sunlight

Drug Therapy for acne, wrinkles, and rosacea

  • acne

    • cleanse twice a day

    • OTC products

    • topical prescription products

    • oral prescription products

  • Wrinkles

    • retinoids

  • Rosacea

    • identify and avoid triggers

    • topical agents

    • antibiotics

  • dermatitis

    • pruritis, inflamed skin that can be caused by a variety of factors

    • symptoms include areas of redness, dry flaky skin, raised or bumpy skins pruritis

psoriasis

  • an immunologic condition

  • manifests as well-defined plaques that are raised, silvery or white

  • can appear anywhere on the body and may be very small or quite large

  • exacerbated by stress and environmental factors

Topical Corticosteroids

  • anti-inflammatories

  • cortisone; steroids

  • for many types of skin

  • many forms

  • potency (fluorinated=stronger)

  • Rx and OTC

  • end in “sone” and “olone”

Hair Loss

  • androgenic alopecia

    • referred to as male-pattern baldness

    • affects men and women

    • hair follicles shrink, producing finer hair

  • Alopecia areata

    • a chronic inflammatory condition affecting hair follicles

    • may cause areas of complete hair loss

Antihistamines

  • inhibit inflammation, redness, and itching

  • work if histamine is released

  • antipruritic

  • Combination: Caladryl (calamine + diphenhydramine)

Skin Infections

  • bacterial infections

    • impetigo

      • caused by S. aureus or Streptococcus

      • superficial, highly contagious; common in an early childhood

    • erysipelas- don’t worry about

      • A form of cellulitis that spreads rapidly through the skin

    • folliculitis

      • Inflammation of a hair follicle, surrounding tissue not affected

    • Furuncle

      • Begins in a sebaceous gland and associated hair follicle; more extensive and deep than folliculitis

    • Carbuncle

      • a coalescent mass of infected follicles; deeper than a furnicle

  • Fungal infection

    • candidiasis

      • Caused by Candida albicans; lesions in the vagina and mouth

    • ringworm

      • caused by a microscopic fungus

      • infects the skin or nails

      • spreads outward as the center heals, leaving a ring

Yeast Infection

  • cause: candida albicans

  • treated the same as fungal infections

Fungal Skin Infections

  • ringworm (tinea corporis)

  • athlete’s foot (tinea pedis ic)

  • jock itch (tinea crudis)

  • nails (onychomycosis)

Viral infections

  • Herpes simplex virus (HSV

    • HSV type 1 associated with cold sores

    • HSV type 2 associated with genital infection

  • Herpes Zoster

    • Chicken Pox (Vaccine- varicella – Varivax)

    • Shingles ( Vaccine – varicella life and non-live –Zostavax and Shingrix)

    • Wart

    • The epidermal tumor is caused by a virus

    • Viruses may lie dormant and later cause reinfection

    • Topical Salicylic acid preparations, i.e Compound W, Duoplant

External Parasites

human lice

  • wingless parasitic insects that feed on human blood

  • spread by direct contact with infested person’s head, body, or personal items

  • symptoms of infestation is itching

types

description

body lice
(pediculosis
corporis)

-Live on clothing and moist areas of the body
-Treated by removing clothing, bathing patient,
putting on clean bedding and clothes

Head lice
(pediculosis
capitis)

-Lives on scalp and hair-Feed on blood from the scalp which produces itching
-Female louse has a life span of 40 days, lays 10
nits/day
- Nits stick to hair close to the scalp and hatch in 8 days.
- Nits are seen by shining a bright light on the scalp
- Nits are white and cannot be shaken off.

Pubic lice
(pediculosis
pubis

-Live in the pubic area
- Infection may resemble dermatitis and be itchy.
- Transmitted by sexual contact 2

types of lice:

  • body lice

    • Shower or bathe, and apply 20-30g of cream or lotion to the whole body; then wash off in 24 hours

    • repeat once a week

  • head lice

    • Massage two ounces of less of cream or lotion into premoistened hair for four minutes, and rinse out

    • repeat once a week

  • pubic lice

    • Apply a thin layer of cream or lotion that extends to the thighs, trunk, and axillary regions; wash off in 24 hours.

    • repeat once a week

Scabies

  • type of mite

  • Female burrows in epidermis secretes substances that disintegrate the skin, then feeds on the skin

  • Intense itching at night caused by increased activity of mitese, feeding, and deposition of feces.

  • Lesions are slightly elevated, wavy grayish-white burrows.

  • Lesions often seen in webs between fingers

Drug Therapy for Scabies

  • permethrin

    • adults

      • apply to the skin from neck to feet

    • infants and older adults

      • apply to the scalp and face

    • everyone

      • wash off 8-12 hours later

  • Crotamiton (Eurax)

    • cream for the intense itching

Antiseptics and Disinfectants

  • Use of Disinfectants

    • instruments

      • Best to use two separate agents with different mechanisms of action

    • treats infections in the mouth and on the body

      • The oral cavity is difficult to disinfect because very few drugs adhere to the mucosal lining long enough to overcome bacteria

Types of Disinfectants

  • Povidone-iodine (Betadine)- wounds

  • Zinc oxide (Desitin)- diaper rash

  • Chlorhexidine gluconate (Peridex, Perichlor, Periogard)- antibacterial dental rinse

Decubitus Ulcers

Are caused by contact pressure applied to the area of the skin. It happens when patients are confined to beds or wheelchairs. The skin is meant to skin if not the skin will become thin. It is common near bony areas such as the tailbone, heels, hips, spine, and elbows. How to prevent it? Turn patients in every 2 hours. Apply for skin protection. Using air beds. Ensure good hydration and nutrition.

Treatments for Ulcers

  • debridement

    • Removes dead, crusted, or contaminated tissue around a wound to promote healing

    • can be painful so pain medication is given prior

  • Positioning

    • Reposition bedridden patients every 2 hours

    • Prevents new wounds from developing

    • Prevents existing wounds from getting worse

    • 24-hour care is required if they are unable to move independently

Burns

  • causes

    • heat and thermal injury

    • electrical and chemical sources

  • determinants of prognosis

    • severity

      • how deep the damage is

    • % of body surface affected

      • Determined by dividing the body into major sections

Drug Regimens and Treatments for Burns

  • cooling and cleaning

    • cool water

    • A mixture of refrigerated and room-temperature saline

    • Water-soaked gauze pads cooled in the refrigerator

  • Blisters

    • not to be drained or popped

Drug Regimens and Treatments for Burns:
Silver Sulfadiazine

Protects non-superficial wounds from bacterial infection. Side effects are skin discoloration, skin rash, and a burning sensation. Contraindications are pregnancy and infants under 2 months. Cautions and considerations would be allergies Careful wound care and monitoring of tissue necrosis

Burns and Skin Ulcers

  • mechanism for healing

    • debridement

    • granulation

    • drainage

  • debridement

    • dead tissue is removed

    • new tissue forms at the base

  • Granulation

    • when the lumpy, pink tissue containing new connective tissue and capillaries form around the edges of a wound

  • Drainage

Other Drugs

  • drugs to absorb exudates

    • Duoderm

  • Drug for debridement

    • collagenase (Santyl)

  • Drugs for granulation

    • polyurethane foam dressing (eg, Allevyn)

Complementary and Alternative Therapies

  • aloe gel

    • Has wound-healing, antibacterial, and antifungal properties

    • In concentrated form, used for treating mild psoriasis and burn-wound healing

    • Needs to be applied three times a day for up to four weeks

    • Concentrations in many lotions and oils are not sufficient to do more than moisturize

  • Clove Oil

    • An antiseptic used on exposed dentin when combined with zinc oxide or zinc acetate

  • Lanolin, Cocoa Butter, Vegetable or Seed Oils

    • Added as moisturizers to creams and lotions

    • Keep skin hydrated and soft

  • Vitamins A, D, and E

  • Emollients added to moisturizers to promote skin health and healing

Chapter 16

The Immune System, Bacterial Infections, Fungal Infections, and Drug Therapy

Anatomy and Physiology of the Immune System

  • The immune system helps the body fight infection

  • Organs of the immune system and their functions

    • The bone marrow produces white blood cells which
      fight infection.

    • The thymus produces T lymphocytes.

    • The lymph nodes trap microbes, and the lymph vessels carry the fluid of the lymphatic system to cleanse body tissues.

    • The spleen removes microbes from the blood.

  • Immune System

    • bodies built-in defense mechanisms against pathogens

    • made of specialized cells, tissues, and organs

cells of the Immune System

  • leukocytes: white blood cells

    • agranulocytes: don’t contain granules in the cytoplasm

    • Granulocytes: contain granulates in the cytoplasm

      • Monocytes: circulate in the blood; move into infected tissue

        • macrophages: mature; ingest invaders

        • lymphocytes: detect specific pathogens; support immunity

  • Types of immunity

    • innate immunity

      • present from birth

      • first line of defense that is quick to fight pathogens

      • forms of innate immunity

        • integumentary and GI system, which forms a barrier between the body’s interior and outside pathogens

        • Phagocytic leukocytes, which break down pathogens

          • Eosinophils, leukocytes, neutrophils

          • The complement system, which consists of enzymes and proteins

            • histamine, leukotrienes, prostaglandins

Infectious Diseases

  • define

    • Disorders caused by pathogenic organisms such as bacteria, viruses, fungi, or protozoa

  • Infectious Disease Prevention

    • handwashing

      • using soap and water to wash hands

    • hand hygiene

      • Cleaning hands using alcohol-based products that do not require water

    • Universal precautions

      • Personal safety standards to protect against accidental exposure to pathogens

      • Includes personal protective equipment

      • Sanitizing

Bacterial Infections

  • Bacteria: single-celled organisms

    • can be found on the skin, in the mouth, in the gastrointestinal tract

    • cause disease when they grow uncontrollably or enter the bloodstream

  • Pathogenic bacteria: can cause an infection

  • Bacterial Infection: bacterial growth in body tissues can cause tissue damage

    • symptoms of bacterial infection

      • Fever of >101 degrees Fahrenheit and white blood cell count of >12,000/mm^3

Characteristics

Description

oxygen requirement

-aerobic bacteria need oxygen to live--anaerobic bacteria can survive without oxygen

bacterial shape

-cocci are spherical-bacilli are rod-shaped-spirochetes are spiral-shaped arrangement

arrangement

clusters, repair thickness

the thickness of cell walls

- Gram-positive bacteria have a thick cell wall that absorbs crystal violet- gram-negative bacteria have a thin cell wall that does not absorb crystal violet

Antibiotic Selection

  • antibiotic: a chemical substance with the ability to kill or inhibit bacterial growth

  • factors considered in an antibiotic selection

    • type of pathogen suspected

    • antibiotic’s spectrum of activity

    • location of the pathogen

  • identifying bacteria and selecting a drug treatment

    • sample or swab taken is taken from the parties

    • the sample is grown in a laboratory culture

    • culture and sensitivity tests performed

  • a broad spectrum is effective against multiple organisms

  • Empirical treatment: using medication to treat a patient before the specific microorganism causing the infection is identified

  • nosocomial infection: acquired while a patient is in a hospital or nursing home

  • bactericidal agent kills the invading agent

  • bacteriostatic agent: inhibits the growth of bacteria

  • clinical and microbiologic responses are used to evaluate the outcome

Antibiotic Side Effects and Dispensing Issues

  • Parenteral antibiotics should be mixed exactly as directed

    • drug may cause adverse effects if not done correctly

  • The counting tray should be swabbed with alcohol after counting oral antibiotics

  • most antibiotics are taken on an empty stomach, but some should be taken with food

  • Antibiotics may decrease the effectiveness of birth control pills

  • Antibiotics should be given around the clock

Antimicrobial Resistance

  • antibiotic resistance: is the ability of bacteria to develop defense mechanisms that resist or inactivate antibiotics used

  • preventing resistance

    • prescribing antibiotics only when necessary

    • using auxiliary labels that remind patients to complete the entire course of antibiotics

Storage and Liquid Antibiotics

  • storage requirement

    • some antibiotics must be refrigerated

    • some antibiotics may be stored at room temperature

    • technicians may discuss this information with the patient

  • Medication Flavors

    • technicians may suggest and change flavors

    • the flavored medication increases adherence in children

Ophthalmic Antibiotics

  • manufacturing requirements

    • same pH as the eye

    • sterility

  • Dispensing Issues

    • often rejected due to expense

    • need to inform the prescriber of alternatives

STIs and Drug Treatment

  • Sexually Transmitted Infections: genital-system infections transmitted by sexual activity

  • They were formally known as STDs and general diseases

  • preventing STIs

    • no sex

    • wait until marriage

    • use a condom

  • Chlamydia

    • caused by chlamydia trachomatis

    • often asymptomatic

    • typically occurs with gonorrhea

    • potential for reinfection if a partner is not treated

  • Gonorrhea

    • caused by Neisseria gonorrhoeae

    • Symptoms: painful urination and discharge of pus from the penis, abdominal pain due to pelvic inflammatory disease

    • Long-term complications include sterility in patients with a penis.

    • Risk of systemic infections in any patient if untreated

    • Occurs frequently with chlamydia

  • Syphilis

stages

Description

primary-stage infection

-chancre at the site of infection which heals in weeks-fluid from chancre highly infectious-if not treated, will progress to the secondary stage

secondary-stage Infection

-skin rash, patchy hair loss, malaise, mild fever-symptoms subside, the disease becomes latent

Late or tertiary-stage infection

-occurs after at least 10 years-rubbery tissue masses in organs and deafness, blindness, CNS lesions, perforation of the roof of the mouth

  • Other Sexually Transmitted Infections

infection

description

nongonococcal urethritis

-Caused by catheters, chemical agents, or sexual transmission-Genital discharge, burning while urinating, itching-May progress to PID in patients with a uterus, cervix, fallopian tubes, or ovaries

Gardnerella vaginitis

-Characterized by vaginal discharge and odor-Caused by an interaction between the organism and anaerobic bacteria in the vagina-Frothy discharge, fishy odor, vaginal pH of 5 to 6

trichomonas vaginalis

-Bacteria found in individuals of any sex-Potential for infection if vaginal acidity is disturbed-Profuse, yellowish, or light cream-colored discharge with a disagreeable odor that irritates, burning, and itching

  • Medications and their use

medication

infection

azithromycin

certain stages of syphilis, gonococcal infections

ceftriaxone

penicillinase-producing bacteria

doxycycline

lymphogranuloma venereum, which is caused by chlamydia trachomatis

metronidazole

Gardnerella, vaginalis

tetracycline and erythromycin

chlamydia

penicillin G benzathine

syphilis, especially during the primary stage

Fungi and Diseases

  • fungus: Single-celled eukaryotic organism

    • mushrooms, yeasts, mold

  • They are different from green plants since they lack chlorophyll and reproduce using spores

  • They are different from animal cells and bacteria by having rigid cell walls

  • they are different from human cells since human cell membranes contain cholesterol and fungi’s cell membranes contain ergosterol

  • Infectious Disease Treatment

    • Fungal Infections

      • Dermatophytes are fungal infections of the skin

      • Candidiasis causes vaginal yeast infections and oral thrush

      • not all fungi cause infections

        • states of immunodeficiency

        • drug therapy

        • poor nutrition

        • IV catheters

        • Some cancers

        • Human immunodeficiency virus

Antifungal medication polyenes azoles, echinocandins, misc

drug regimens and treatment for fungal infections: antifungal drugs

Fighting Parasitic and Protozoal Infections

  • Infectious Disease Treatment

    • parasitic and protozoal infections

      • Parasites are organisms that live off a host

      • protozoa are single-celled organisms that usually cause infections through oral-fecal route

      • Giardiasis is an intestinal infection caused by protozoa and is carried in bird droppings, deposited in water or on vegetation

Common Parasitic and Protozoan Organisms and Infections

  • Therapy often combines 2 or 3 drugs

    • quinine

    • hydroxychloroquine-Plaquenil

    • doxycycline

    • tetracycline

    • clindamycin

    • atovaquone- Malarone

    • Mefloquine-Lariam

Complementary and Alternative Therapies

  • echinacea: used to treat the common cold, RTIs, and vaginal yeast infections

    • reduces the severity and length of symptoms

    • variable concentrations in the products availably

    • no standard dose established

    • must be used multiple times a day and started at the first signs of infections

  • Zinc

    • used to enhance wound healing and prevent wound-associated infections

    • no well-established dose

  • Garlic: used for immune system stimulation and prevention of infections

    • used topically for dermatophyte infections

    • side effect of oral garlic dermatitis or burns

    • drug interaction for garlic: anticoagulants

  • Ginseng: used for several conditions including prevention of infection

    • has been shown to reduce the length of cold sores and the risk of recurrence

    • side effects are headaches

    • drug interaction with ginseng: warfarin

  • Vitamin C: used to boost the immune system and for its antioxidant effects

    • side effects of high doses are diarrhea, upset stomach, kidney stones

Immune System, Viral Infections, and Drug Therapy

17.1 Viruses and Viral Infections

Virus

  • an infectious agent smaller than a bacterium, not a whole-cell organism

  • Individuality consists virus particle is a virion

  • Consists of a core of DNA or RNA surrounded by a capsid

  • must attach itself to a host cell to replicate

Ways that viruses spread

  • direct contact, ingestion of contaminated food or water, inhalation of airborne particles, exposure to contaminated body fluids or equipment

Viruses and Viral Infections

  • virus

    • a minute infectious agent smaller than a bacterium

    • consists of segments of DNA or RNA surrounded by a protein coating or capsule

    • requires host cells to reproduce

Stages of Viral Infection

  1. Attachment: Virion attaches to cell receptors

  2. Penetration: virion penetrates the cell and escaped into the cytoplasm

  3. uncoating: virion sheds capsid and presents DNA or RNA to the cell nucleus

  4. Replication and Assembly: Virion DNA or RNA causes cells to produce new viral particles

  5. release: duplicated viruses are released from the host cell

Significant Viral Infection

  • Influenza: symptoms include malaise, myalgia, headache, chills, fever

    • Patients at risk for complications include the elderly; patients with cardiovascular disease, renal disease, diabetes, and respiratory conditions; immunocompromised patients.

    • Annual vaccinations are recommended for those at risk for complications.

  • Hepatitis: inflammation of the liver

    • various types referred to as hepatitis A through G

    • severity range from benign to serious

  • HIV: considered a chronic disease

    • regimens of at least three drugs

    • important to monitor for drug interactions

Classification of Viral Infections

  • Viral Duration and Severity

    • An acute viral infection quickly resolves.

    • Chronic viral infection has a long course with periods of remission.

    • A slow viral infection maintains a progressive course over months or years.

  • The extent of Viral Infection

    • A local viral infection affects tissues of a single system.

    • A generalized viral infection has spread to other tissues.

  • Latent Viruses

    • A virus that lies dormant
      after infection and then later becomes active

    • Examples: herpesviruses
      and HIV

Virus and Host-Cell Interaction

  • Immunoglobin

    • A type of antibody produced by host cell B lymphocytes

    • An immunoglobulin that matches a viral protein may prevent the virus from attaching to a cell or may destroy the virus.

  • Interferon

    • Induces production of proteins that may disrupt viral replication or prevent spread to uninfected cells

  • Vaccination

    • description

      • Exposing a patient to a component of a virus or an altered viral strain to produce antibodies

      • When later exposed to the actual virus, the infection does not develop because natural defenses have been primed.

    • Viral Mutations

      • It makes effective vaccine production difficult.

      • An example is the influenza vaccine which must be reformulated each year

Chapter 17.2 Antiviral Agents (Nonretroviral)

  • challenges of treating viral infection

    • Viruses use host’s cellular processes to function and replicate.

    • Medications which block the virus life cycle are often toxic to the patient.

    • The similar challenge presented by chemotherapy agents for cancer

  • Antiviral Drugs

    • formulated to seek out a virus and prevent its replication without interfering with normal host function

Therapeutic Uses of Antiviral Drugs

  • Herpesvirus Infections

    • Herpes Simplex 1 (HSV-1)

    • Herpes Simplex 2 (HSV-2)

    • Varicella-zoster (chicken pox/ shingles)

    • cytomegalovirus (human herpesvirus 5)

  • Influenza

  • Respiratory Syncytial Virus (RSV)

Antiherpes Agents

  • Work Wise: Ganciclovir and Valganciclovir are considered hazardous drugs, so it is essential to follow handling precautions as outlined in the pharmacy’s workplace policies and procedures

Anti-Influenza Agents

Other Antiviral Agents

HIV/AIDS and Antiretroviral

  • Define

    • retrovirus: uses RNA as its genetic material

    • Reverse transcriptase: The enzyme retroviruses use to become part of the host’s DNA

    • Human immunodeficiency virus (HIV): A retrovirus that attaches to receptors on the surface of CD4 cells

      • It uses reverse transcriptase to convert its genetic material from RNA to DNA

    • Acquired Immunodeficiency Syndrome (ADIS): Syndrome which occurs when patients have advanced and severe forms of
      HIV

      • You can have HIV without having aids.

  • Antiretroviral drugs

    • difficult to tolerate due to side effects and drug interactions

    • Can be combined in a “cocktail” that attacks viral replication in multiple stages

    • must be taken chronically

    • some cocktails available as a single tablet

  • NRIs and NtRTIs

    • They inhibit reverse transcriptase, which prevents the formation of a DNA copy of viral RNA

    • Class Side Effects are nausea, diarrhea, and abdominal pain which improves in the first few weeks. More permanent effects are lactic acidosis with hepatic steatosis

NRITs and NtRTIs

NNRTIs

  • Protease Inhibitors

    • work by decreasing the formation of the protease enzyme, which cleaves specific HIV protein precursors necessary for the construction of new infectious virions

    • Typically combined with other HIV drugs; metabolized through cytochrome P-450 resulting in many drug interactions which are sometimes severe; not to be used with statins;

    • Side effects include redistribution of body fat, facial atrophy, breast enlargement, hyperglycemia, hyperlipidemia, the possibility of increased bleeding episodes in patients with hemophilia.

Protease Inhibitors

Fusion Inhibitors

  • Chemokine Coreceptor Antagonist

    • medication is maraviroc (Celestin)

    • It works by preventing HIV from attaching and entering immune cells.

    • special characteristic is that it has to be given with other antiretroviral drugs

    • Side effects of Chemokine Coreceptor Antagonists include cough, abdominal pain, dizziness, fever.

    • risk for hepatotoxicity with allergic features monitor closely for infection

Integrase Inhibitors

  • Responding to Exposure to HIV

    • Healthcare worker risks

      • exposure to blood and other bodily fluids

      • needlestick injuries

    • Postexposure Prophylaxis

    • can be decreased the risk of infection by 80% should start treatment with 2 hours

  • Combining antiretroviral medications

    • advantage

      • improve adherence

    • disadvantage

      • fixed doses unsuitable for unstable patients

    • examples

      • Lamivudine-zidovudine (Combivir)

      • Elvitegravir-cobicistat-emtricitabine-tenofovir (Stribild)

      • Emtricitabine-tenofovir (Truvada)

Immunization

  • Immunity is resistance to an infectious disease.

  • Immunization: the process whereby a person acquires immunity or resistance to an infectious disease

  • Methods of acquiring immunity:

    • Passive Immunity: antibodies transferred to an individual

      • occurs naturally during pregnancy

      • happens artificially during administration of immunoglobulin

    • Active Immunity: individual makes their own antibodies

      • naturally through exposure to pathogens

      • artificially through vaccines

  • Purpose is to prevent viral infections by providing immunity

  • exposes a patient to a component of a virus or altered viral strain

  • development of antibodies specific to the virus

  • patient’s defenses primes for subsequent exposure

  • viral mutations

    • patient’s defenses do not recognize mutated virus since they were primed against the original virus

    • example is influenza which is redone yearly

  • A vaccine induces the body to make antibodies which recognize the virus antigen and fight infection

  • Live Attenuated Vaccines: use live but weakened pathogens to induce an immune response

  • Inactivated Vaccines: use pathogens that have been killed

  • Immunization Schedule

    • Schedule source: adult and childhood vaccination schedules are published by the CDC

    • vaccines for children: most lead to a lifetime immunity

      • boosters given for continued protection

    • vaccines for healthcare workers: hepatitis B vaccination and annual influenza vaccine often required by employers

CDC recommended immunizations

  • Common Vaccines

    • Travel Vaccines

      • Recommended when traveling from areas of low infection rates to areas of high infection rates

      • Given two or more weeks before travel to give the immune system time to mount sufficient response

      • Travel clinics may be located in clinics or pharmacies and provide immunizations and advice about what vaccines are necessary

    • Dosage Forms and Administration

      • Most require storage in refrigerator or freezer, storage temperatures strictly followed

      • If warmed to room temperature must be used right away

      • Not to be refrigerated again if warmed to room temperature

      • Must be used within minutes to hours once reconstituted

      • Advance mixing of vaccines not recommended

      • Vaccines not to be mixed in same syringe with other medications

    • Cautions and considerations

      • Patients to receive vaccine information sheet (VIS) and sign a consent form as required by law.

      • Healthcare personnel trained in vaccine administration must be trained in CPR

  • Complementary and Alternative Therapy

    • Andrographis

      • May reduce symptom severity and duration of influenza if started within 36 to 48 hours

        • Side effects include chest discomfort, headache, nausea, rash.

        • May interact with anticoagulants, blood pressure medications, and immunosuppressants

      • Colloidal silver

        • Used topically and orally for infection

        • Side effects include argyria, neurologic deficits, kidney damage.

      • Elderberry

      • May be used for influenza when initiated within 48 hours of symptoms

      • Oscillococcinum