pharmacology part 1
TRANSCRIPT
GENERAL PRINCIPLES OF PHARMACOLOGY
Part 1 Topics
Drug Names Sources of Drug Products Drug Classifications Food & Drug Administration Medication Administration Properties of Drugs
Pharmacology is the study of drugs and their actions
on the body.
Drugs are chemicals used to diagnose, treat, and prevent
disease.
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.
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.
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
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.
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.
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.
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.
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.
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
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
Part 1 Summary
Drug Names Sources of Drug Products Drug Classifications Food & Drug Administration Medication Administration Properties of Drugs