Chapter 3Dispensing of

Pharmacologic Agents

Chapter 3 Topics

• The Prescription• “Rights” for Correct Drug Administration• Dosage Forms and Routes of Administration• Factors that Influence Drug Action• Endogenous Chemicals that Affect Drug Action

and Response• Teaching Patients Medication Management

Learning Objectives

• Know the components of the prescription, including the commonly used abbreviations.

• Understand the rights of correct drug administration.• Recognize common dosage forms.• Know the routes of administration.• Recognize factors that influence the effects of drugs,

particularly in the elderly and pediatric populations.• Know the effects natural chemicals have on drug action

and response.• Understand the immunization process.

The Prescription

The Prescription

Abbreviation Translation

ac before meals

bid twice a day

c with

cap capsule

DAW dispense as written

D/C discontinue

g gram

The Prescription

Abbreviation Translation

gr grain

gtt drop

hs at bedtime

IM intramuscular

IV intravenously

L liter

mcg microgram

The Prescription

Abbreviation Translation

mEq milliequivalent

mL milliliter

NKA no known allergy

NKDA no known drug allergy

npo nothing by mouth

pc after meals

PO by mouth

The Prescription

Abbreviation Translation

prn as needed

q every

qh every hour

q2h every two hours

qid four times a day

qs a sufficient quantity

stat immediately

The Prescription

Abbreviation Translation

tab tablet

tid three times daily

ud as directed

wk week

Problematic Abbreviations

Dangerous Abbreviation

Correct Form to Use

µg Microgram or mcg

qd every day

qod every other day

U units

MgSO4 magnesium sulfate

MSO4 morphine sulfate

.2 0.2

2.0 2

Problematic Abbreviations

• Institute for Safe Medication Practices (ISMP)– Lists dangerous abbreviations and other safety

tips.– Check out the site at www.ismp.org.– Review Appendix B in the textbook for

additional safety tips.

Discussion

What makes an abbreviation dangerous?

What is the role of the pharmacy technician when a prescription arrives with a dangerous abbreviation?

“Rights” for Drug Administration

Right Patient

Right Drug

Right Strength

Right Time Right Route

Discussion

How do the “rights” for correct drug administration help avoid dispensing errors?

What other things should a pharmacy technician check when dispensing a medication?

Mediation Label

Dosage Forms and Routes of Administration

• Peroral (PO, by mouth) Dosage Route– Oral (swallowed)– Sublingual (under the tongue)– Buccal (dissolves in the check)

Dosage Forms and Routes of Administration

• Parenteral Dosage Route– Intravenous (vein)– Intra-arterial (artery)– Intracardiac (heart)– Subcutaneous (beneath the skin)– Intramuscular (muscle)

Dosage Forms and Routes of Administration

• Topical Dosage Route– Transdermal (skin surface)

– Conjunctival (conjunctiva) or Intraocular (eye)

– Intranasal (nose)

– Aural (ear)

– Intrarespiratory (lung)

– Rectal

– Vaginal

– Urethral

Dosage Forms and Routes of Administration

• Peroral (PO, by mouth) Dosage Formstablets, capsules, solutions, syrups, elixers, suspensions, magmas, gels, powders, trouches/lozenges

Dosage Forms and Routes of Administration

• Parenteral Dosage Forms– Solutions– Suspensions

Dosage Forms and Routes of Administration

• Topical Dosage Formsointments, creams, pastes, powders, aerosols, lotions, transdermal patches, sprays, inhalants, suppositories, enemas, emulsions, sponges, gels

Factors that Influence Drug Action

• Review: What are the four phases of the pharmacokinetic process?

Absorption

Distribution

Metabolism

Elimination

Factors that Influence Drug Action

• AgePediatric patients and elderly patients may need a reduced dose because of smaller size or inability of liver to metabolize medication

• DiseaseSpecific diseases may hinder the pharmacokinetic process of some drugs

• Mental State, Genes, Gender

Considerations for Elderly Patients

Physiologic Function Changes– Optic

– Auditory

– Gastrointestinal

– Pulmonary

– Cardiovascular

– Urinary

– Hormonal

– Composition of the body

Considerations for Elderly Patients

• Altered Drug Responses

• Adverse Drug Reactions (ADRs)

• Polypharmacy

• Noncompliance

Considerations for Pediatric Patients

• Wide variation between age and degree of organ-system development

• Reevaluate all doses at regular intervals.

• Be sure the dosage is appropriate for the child’s age.

• Always double-check all computations.

Discussion

What should a pharmacy technician do when a parent is struggling to determine the best dose of an OTC medication for a pediatric patient?

Discussion

What should a pharmacy technician do when a parent is struggling to determine the best dose of an OTC medication for a pediatric patient?

Answer: Ask the pharmacist to determine the child’s dose for the caretaker if the dose information is not provided.

Immunization

What are the two types of immunity?

Immunization

What are the two types of immunity?– Active immunity

– Passive immunity

Immunization

What are the two types of immunity?– Active immunity

Coming in contact with an infectious agent or an inactivated part of an infectious agent through a vaccine

– Passive immunityReceiving antibodies that were formed by another person or animal that developed them in response to being infected

Immunization Schedule

Endogenous Chemicals that Affect Drug Action and Response

Two types of receptors that histamine acts on:– H1 receptors mediate the contraction of smooth

muscle of the bronchi and intestine

– H2 receptors mediate the action of histamine on gastric secretion and cardiac acceleration

Endogenous Chemicals that Affect Drug Action and Response

Two types of drugs that block the histamine receptors:

– Antihistamines block H1 receptors

– H2 blockers

• cimetidine (Tagamet)• ranitidine (Zantac)• famotidine (Pepcid)• nizatidine (Axid)

Allergic Response

Allergic Diseases

• Allergic rhinitis

• Hay fever

• Allergic dermatitis, eczema

• Contact dermatitis

• Urticaria (hives)

Drug Therapy for Allergies

• Free environment of allergens (if possible)

• Corticosteroids

• Short-term relief of symptoms with antihistamines

• Long-term desensitization programs

Prostaglandins

• Mediators of several physiologic processes• Include PGA, PGB, PGE, and PGF• Actions

– Endocrine system– Cardiovascular system– Gastrointestinal system– Pulmonary system– Inflammatory

Teaching Patients Medication Management

Goal: ComplianceA patients’ adherence to the dose schedule and other particular requirements of the specific drug regimen

Discussion

What kinds of information help improve patient compliance?

Discussion

What kinds of information help improve patient compliance?

Answer: – Methods of administration– How to make swallowing easier– Times and time intervals for administration– If medication should be taken with food or

not– Possible side effects– How long the medication should be taken

Discussion

What can the pharmacy technician do to help patients manage their medications properly?

Teaching Patients Medication Management

Teaching Patients Medication Management