GENERAL PRINCIPLES OF PHARMACOLOGY

Part 1 Topics

Drug Names Sources of Drug Products Drug Classifications Food & Drug Administration Medication Administration Properties of Drugs

Drugs are chemicals used to diagnose, treat, and prevent

disease.

Pharmacology is the study of drugs and their actions

on the body.

Names of Drugs

Chemical…states its chemical composition and molecular structure.

Generic…usually suggested by the manufacturer.

Official…as listed in the U.S. Pharmacopeia.

Brand…the trade or proprietary name.

Chemical Name7-chloro-1, 3-dihydro-1, methyl-5-phenyl-2h-1

Generic Name diazepam

Official Name diazepam, USP

Brand Name Valium®

Names of Drugs

Sources of Drug Information

United States Pharmacopeia (USP)

Physician’s desk reference (PDR)

Drug information

Monthly prescribing reference

AMA drug evaluation

EMS field guides

Components of a Drug Profile

Name Classification Mechanism of

Action Indications Pharmacokinetics Side Effects

Routes of Administration

Contraindications Dosage How Supplied Special

Considerations

Names

Most Frequently Include Generic and Trade Names

Classification

The broad group to which a drug belongs. Knowing classifications is essential to understanding the properties of drugs.

Mechanism of Action

The way in which a drug causes its effects; its pharmacodynamics.

Indications

Conditions that enable the appropriate administration of the drug (as approved by the FDA).

Pharmacokinetics

How the drug is absorbed, distributed, and eliminated; typically includes onset and duration of action.

Side Effects/Adverse Reactions

The drug’s untoward or undesired effects.

Routes of Administration

How the drug is given.

Contraindications

Conditions that make it inappropriate to give the drug.

…means a predictable harmful event will occur if the drug is given in this situation.

Dosage

The amount of the drug that should be given.

How Supplied

This typically includes the common concentration of the available preparations; many drugs come in different concentrations.

Legal

Knowing and obeying the laws and regulations governing medications and their administration is an important part of a paramedic’s career.

These include federal, state, and agency regulations.

Federal…

Pure Food & Drug Act of 1906 Harrison Narcotic Act of 1914 Federal Food, Drug, & Cosmetic

Act of 1938 Comprehensive Drug Abuse

Prevention & Control Act of 1970

State vs. Local Standards

They vary widely. Always consult local protocols

and with medical direction for guidance in securing and distributing controlled substances.

New Drug Development

Providing Patient Care Using Medications (1 of 4)

Know the precautions and contraindications for all medications you administer.

Practice proper technique. Know how to observe and document

drug effects.

Providing Patient Care Using Medications (2 of 4)

Maintain a current knowledge in pharmacology.

Establish and maintain professional relationships with other healthcare providers.

Understand pharmacokinetics and pharmacodynamics.

Providing Patient Care Using Medications (3 of 4)

Have current medication references available.

Take careful drug histories including: Name, strength, dose of prescribed medications; Over-the-counter drugs; Vitamins; Herbal medications; Allergies.

Providing Patient Care Using Medications (4 of 4)

Evaluate the patient’s compliance, dosage, and adverse reactions.

Consult with medical direction as needed.

Know the 6 Rights of Medication

Administration Right Medication Right Dosage Right Time Right Route Right Patient Right Documentation

Special Considerations

Pregnant Patients Pediatric Patients Geriatric Patients

Pregnant Patients

Ask the patient if there is a possibility that she could be pregnant.

Some drugs may have an adverseeffect on the fetus of a pregnant female.

Teratogenic drug…is a medicationthat may deform or kill the fetus.

Pharmacokinetics

Absorption…a drug must find itsway to the site of action.

Distribution…a drug must then be distributed throughout the body.

Pharmacokinetics

Biotransformation…the process of breaking down, or metabolizing, drugs.

Elimination…drugs must eventually be excreted from the body.

Drug Routes (1 of 2)

Enteral: Deliver medications by absorption

through the gastrointestinal tract. Oral, orogastric/nasogastric, sublingual,

buccal, rectal.

Drug Routes (2 of 2)

Parenteral: Delivers medications via routes other

than the GI tract. Include intravenous, endotracheal,

intraosseous, umbilical, intramuscular, subcutaneously, inhalation, topical.

Enteral – examples (1 of 2)

Oral (PO) — good for self-administering drugs.

Orogastric (OG) / Nasogastric (NG) — alternate method to providing POmedications.

Sublingual (SL) — excellent absorption without problems of gastric acidity.

Buccal — between the cheek/gum.Similar to sublingual.

Rectal (PR) — reserved forunconscious or vomiting patients.

Enteral – examples (2 of 2)

Parenteral – examples

(1 of 3)

Intravenous (IV) — preferred route inemergencies.

Endotracheal (ET) — alternate route in emergencies for select medications.

Intraosseous (IO) — alternative use inemergencies, mostly in pediatrics.

Umbilical — provides alternate access in newborns.

Intramuscular (IM) — slower absorption than IVs.

Subcutaneous (SQ) — slower absorption than IM.

Parenteral – examples

(2 of 3)

Inhalation — very rapid absorption via the lungs.

Topical — delivers drugs directly to the skin.

Parenteral – examples

(3 of 3)

Most emergency medications are given

intravenously to avoid drug degradation in the liver.

Drug Forms

Solid Forms: Such as pills, powders, suppositories,

capsules.

Liquid Forms: Such as solutions, tinctures,

suspensions, emulsions, spirits, elixirs, syrups.

Pills—drugs shaped spherically to be swallowed.

Powders—not as popular as they once were. Tablets—powders compressed into disk-like

form. Suppositories—drugs mixed with a waxlike

base that melts at body temperature. Capsules—gelatin containers filled with

powders or tiny pills.

Solid Forms

Liquid Forms (1 of 2)

Solutions—water or oil-based. Tinctures—prepared using an alcohol

extraction process. Suspensions—preparations in which

the solid does not dissolve in the solvent.

Emulsions—suspensions with an oilysubstance in the solvent.

Liquid Forms (2 of 2)

Spirits—solution of a volatile drug in alcohol.

Elixirs—alcohol and water solvent; often with flavoring.

Syrups—sugar, water, and drugsolutions.

Actions of Drugs

Drugs that Act by Binding to a Receptor Site

Drugs that Act by Changing Physical Properties

Drugs that Act by Chemically Combining with Other Substances

Drugs that Act by Altering a Normal Metabolic Pathway

Responses to Drug Administration

(1 of 5)

Side Effect—unintended response to a drug.

Allergic Reaction—hypersensitivity.

Idiosyncrasy—drug effect unique to

an individual.

Responses to Drug Administration

(2 of 5)

Tolerance—decreased response tothe same amount.

Cross Tolerance—tolerance for a drugthat develops after administration ofa different drug.

Tachyphylaxis—rapidly occurringtolerance to a drug.

Responses to Drug Administration

(3 of 5) Cumulative effect—increased effectiveness

when a drug is given in several doses. Drug dependence—the patient becomes

accustomed to the drug’s presence in hisbody.

Drug interaction—the effects of one drug alter the response to another drug.

Drug antagonism—the effects of one drug block the response to another drug.

Responses to Drug Administration

(4 of 5)

Summation—also known as additiveeffect, two drugs with the same effectare given together — similar to 1+1=2.

Synergism—two drugs with the sameeffect are given together and produce a response greater than the sum of their individual responses — similar to 1+2=3.

Responses to Drug Administration

(5 of 5)

Potentiation—one drug enhances the effect of another.

Interference—the direct biochemical interaction between two drugs; one drug affects the pharmacology of another drug.

Factors Affecting Drug Response

Age Body Mass Sex Environment

Time of Administration Pathology Genetics Psychology

Drug Interactions

Drug interactions occur whenever two or more drugs are available in the same patient.

The interaction can increase, decrease, or have no effect on their combined actions.

Part 1 Summary

Drug Names Sources of Drug Products Drug Classifications Food & Drug Administration Medication Administration Properties of Drugs