Lecture Clinical procedures for medical assisting (4/e): Chapter 19 – Booth, Whicker, Wyman

Chapter 19 - Principles of pharmacology. After studying this chapter you will be able to: Describe the five categories of pharmacology; differentiate between chemical, generic, and trade names for drugs; describe the major drug categories; identify the main sources of drug information;...

Principles of

Pharmacology

Learning Outcomes

19.1 Describe the five categories of

pharmacology.

19.2 Differentiate between chemical, generic, and

trade names for drugs.

19.3 Describe the major drug categories.

19.4 Identify the main sources of drug information.

Learning Outcomes (cont.)

19.5 Distinguish between over-the-counter

and prescription drugs.

19.6 Compare the five schedules of

controlled substances.

19.7 Describe how to register or renew a

physician with the Drug Enforcement Administration (DEA) for permission to administer, dispense, and prescribe

controlled drugs.

Learning Outcomes (cont.)

19.8 Carry out the procedure for renewing

medications using a telephone.

19.9 Describe how vaccines work in the immune

system.

19.10 Organize patient education topics related to

the use of nonprescription and prescription drugs.

– Ask patients about use

of alcohol and recreational drugs– Provide patient education

• Administration of drugs

– Check state regulations scope of practice

– Understand pharmacologic principles

– Translate prescriptions

– Answer basic patient questions

– Adhere to legal requirements

– Keep accurate records

Drugs and Pharmacology

• Drug – chemical compound used to

prevent, diagnose, or treat disease

characteristics of natural drugs and their

sources

drugs do to the body

Drugs and Pharmacology (cont.)

• Pharmacokinetics – study of what the

body does to drugs

• Pharmacotherapeutics – study of how

drugs are used to treat disease

• Toxicology – study of poisons or

poisonous effects of drugs

Drugs and Pharmacology (cont.)

• Prescribe – physician gives a patient a

prescription to be filled by a pharmacist

• Administer – give a drug by injection,

mouth, or other route that introduces it into

the body

• Dispense – health-care professional

distributes the drug, in a properly labeled

container, to the patient for whom it is

prescribed

– Bacteria and fungi

• Chemical development of natural products

– Synthesis of chemical makeup of a drug

– Manipulation of genetic information

Foxglove – source of 

digitoxin

Apply Your Knowledge

1. What is the role of the medical assistant in

pharmacology?

ANSWER: The medical assistant should be sure the

physician is aware of all medications the patient is

taking, including OTC medications; ask patients about

use of alcohol and recreational drugs; and provide

patient education If the scope of practice permits, the

medical assistant may also be responsible for

administering some medications.

Apply Your Knowledge

2 Matching:

_ Study of poisons A Pharmacokinetics

_ Study of what the body does to drugs B Pharmacognosy

_ Used to prevent, diagnose, or treat disease C Toxicology

_ Study of what drugs do to the body D Pharmacotherapeutics

_ Study of how drugs are used to treat disease E Pharmacodynamics

_ Study of characteristics of natural drug F Drugs

and their sources

• Mechanism of action

of a drug to produce a therapeutic effect

• Interaction between drug and target cells and body’s response

to the interaction

• What the body does to a drug

– Absorption

• Conversion of a drug into a form the body can use

• Allows the drug to enter the blood and tissues

• Rate and extent of absorption depend on

– Route of administration – Characteristics of the drug

– Distribution

• Transportation of a drug from site of administration

to site of action

Pharmacokinetics (cont.)

– Metabolism

• Drug molecules are transformed into metabolites

• Usually in liver, some in kidneys

• Affected by age, genetic makeup, and characteristics of drug

Apply Your Knowledge

What is the difference between pharmacodynamics

and pharmacokinetics?

ANSWER: Pharmacodynamics is the way a drug affects the

body to produce its effect It is the interaction between the

drug and cells and the body's response to the interaction

Pharmacokinetics is what the body does to the drug and

includes absorption, distribution, metabolism, and excretion

of the drug.

Very Good!

• Clinical pharmacology

• Drug names

– Generic – official name

– International nonproprietary name

– Chemical name

– Trade – brand or proprietary name

• Generic and trade names used most often

• Indication and labeling

– Indication – reason(s) for using a drug

– Must be approved by FDA to be part of

labeling– Off-label use

Pharmacotherapeutics (cont.)

• Safety

– Adverse reaction to drug

– Interaction with another medication

– Be alert to patient complaints after starting a

new drug

• Efficacy – drug is working as expected

Pharmacotherapeutics (cont.)

• If a patient complains a drug is not working

– The patient may not understand how the drug

works – Dosage may need to be adjusted

– Therapeutic level may not have been reached

– Wrong drug may have been prescribed

– Some drugs work better for one patient than

another – Some forms of drugs work better

Kinds of Drug Therapy

• Acute – improve a

life-threatening or serious

condition

• Empiric – given before

test results are available

• Replacement – provide chemicals a patient lacks

• Supportive – for a condition other than the primary disease

• Supplemental – avoid a deficiency

– Inform physician of any adverse effects

– Discuss concerns with physician or

pharmacist

Apply Your Knowledge

1 Mr Anderson is complaining that the new

medication does not seem to be working What

may be the reason for this?

Apply Your Knowledge

2 Toxicology includes which of these?

A Poisons and poisonous effects of drugs

Sources of Drug Information

• Sources must be up-to-date

• PDR

– Information provided by pharmaceutical

companies – Information closely resembles package insert

– Published annually

• Drug Evaluations – published

annually by the AMA

Sources of Drug Information

• USP/NF

– Official source of drug standards

– Published about every 5 years

• AHFS – published by the

American Society of

Hospital Pharmacists

The FDA Regulatory Function

Controlled Substances

• Drugs categorized as potentially

dangerous and addictive

• Strictly regulated by federal laws

• Comprehensive Drug Abuse Prevention

and Control Act (1970)

– Created the DEA

– Strengthened drug enforcement authority

– Schedules – based on abuse potential

Schedule Abuse Potential Example

III Lower than II

(moderate dependence) Butabarbital

IV Lower than III

(limited dependence) Diazepam

(very limited dependence) Antidiarrheals

Controlled Substances (cont.)

Controlled Substances (cont.)

• Comprehensive Drug Abuse Prevention and

Control Act (1970)

– Controlled substance

labeling– Doctor registration

– Ordering controlled

substances– Drug security

– Record keeping

– Dispensing records– Inventory records– Disposal of drugs

• Name of the drug

• Amount of drug per dose

– Subscription – directions to the pharmacist

– Signature – patient instructions

Writing Prescriptions (cont.)

Prescription for a

single medication

Writing Prescriptions (cont.)

Prescription for

multiple medications

Writing Prescriptions (cont.)

• Keep prescription

blanks secure

• Telephone prescriptions

– Only at request of the physician

– Follow facility policy– Document carefully

Apply Your Knowledge

Which of the following sources of drug information is most

like the package insert?

A AHFS B PDR C USP/NF D Drug Evaluations

ANSWER:

Match

_ Contains the patient information A Subscription

_ Instructions to the pharmacist C Superscription

Antibody Formation

1 Antigen enters body

2 White cells produce antibodies

3 Antibodies combine with antigens

to neutralize them

4 This arrests or prevents reaction or disease

5 Vaccines stimulate antibody formation and

reduce symptoms if patient is exposed to

disease

– Potential adverse effects

– Methods of storing and

handling

Apply Your Knowledge

ANSWER: Vaccines are administered to a person to

produce reduced sensitivity to or increase immunity to

an infectious disease.

Why are vaccines given to patients?

Patient Instruction on Medications

• Medical assistant role is important

• OTC drugs

– Should not be used to avoid medical care

– May not produce enough therapeutic benefit

– May be dangerous in combination with other

substances or drugs – May mask symptoms or aggravate a problem

Patient Instruction on Medications (cont.)

• Prescription drugs

– Inform patient about special

considerations and drug safety precautions

Patient Instruction on Medications (cont.)

• To prevent medication errors, be sure

patient understands prescription

– How and when to take the medication

– Appropriate language

– Demonstrate if necessary

– Review warnings about

the medication

Apply Your Knowledge

Mrs Del Rosario tells you she does not take any

medication when you are taking her history When you

question her further, she says she takes an OTC pain

medication occasionally and routinely take several herbal

supplements What should you tell her?

ANSWER: You should tell her it is important to report all

medications, including OTC drugs and herbal and other

supplements, to the physician and that they may be

dangerous in combination with other substances or drugs

or may mask symptoms or aggravate a problem.

In Summary

19.1 The five categories of pharmacology include

pharmacognosy, pharmacokinetics, pharmacodynamics, pharmacotherapeutics, and toxicology

19.2 The chemical name of a drug is based upon the

chemical makeup of the medication The generic name is the drug’s official name, and the trade name

is the name given a medication by the manufacturer

A medical assistant should be familiar with both the generic and trade names

In Summary (cont.)

19.3 Drug categories are sometimes named based upon

their action; for example, anticonvulsants are used to treat convulsions (seizures) The major drug

categories and their actions are outlined in Table

19-2

19.4 The main book sources for drug information are the

Physicians’ Desk Reference (PDR), Drug Evaluations, United States Pharmacopeia/National Formulary, and the American Hospital Formulary Service You may

also access medication information from package inserts, at the web site www.rxlist.com, or at other

In Summary (cont.)

19.5 Nonprescription or over-the-counter drugs can be

obtained without a physician’s order For prescription drugs, patients must have a physician’s order

19.6 For drugs that have been classified as controlled

substances because they are potentially dangerous and addictive, extensive regulations apply There are five schedules (I to V) of controlled substances, with schedule I being the most addictive

In Summary (cont.)

19.7 All physicians must be registered with the Drug

Enforcement Administration and follow the legal requirements of the Controlled Substances Act of

1970 to administer, dispense, and prescribe controlled drugs The medical assistant must follow these legal requirements when registering the physician

19.8 Receiving and telephoning medication refills is

frequently done by the medical assistant for all medications except schedule II and III drugs

In Summary (cont.)

19.9 Immunizations usually contain killed or weakened

organisms When given, they stimulate the body to build up a resistance to the organism They are used

to provide immunity against specific diseases

19.10 Patients should be educated about why, when, and

how they should take medications This includes instruction to ensure patient compliance regarding nonprescription and prescription drugs, herbal

remedies, and supplements Patients should also be instructed about the dangers of medication

combinations, the importance of reporting an adverse effect, and maintaining a complete medication list

End of Chapter 19

It is easy to get a thousand  prescriptions but hard to  get one single remedy. 

 ~Chinese Proverb