Pharmacology Terms

PTCE 2026

Pharmacology

the study of drugs and their effects on living organisms

Clinical pharmacology

the study of how drugs work in the human body

Pharmacodynamics

what the drug does to the body

Pharmacokinetics

what the body does to the drug

Components of PK

absorption, distribution, metabolism, excretion

absorption

the process of drugs entering the body into the bloodstream

distribution

the process where the drug is distributed or dispersed throughout the body

metabolism

the process where the drug is broken down by the body

excretion

the drug is eliminated by the body

bioavailability

the amount of the administered drug that reaches the blood circulation and can be used by the body

bioequivalent

when two drugs are absorbed equally into the body; have the same bioavailability

receptors

proteins located inside or on the surface of cells; where drugs must reach to affect the body

agonist drug molecules

mimic normal physiological processes in the body; activates receptors

antagonist drug molecules

inhibits or blocks an agonist from activating a receptor

neurotransmitters

brain chemicals that send messages to the body by binding with specific receptors; often mimicked by agonists

Therapeutic Index (TI)

range of doses at which a medication is both effective and safe

NTI drugs

drugs with a narrow therapeutic index; closely monitored

drug interactions

combinations of a medication with other substances that alter the effects on the body

indication

a reason to use a certain treatment

contraindication

a reason not to use a certain treatment

drug-drug interactions

when two or more drugs react with each other

addition

the combined effects of two drugs is equal to the sum of the effects of each drug taken alone

antagonism

the action of one drug works against the action of another drug

potentation

one drug enhances or prolongs the effect of another drug

synergism

the combined effect of two drugs is greater than the sum of the effect of two drugs

drug-disease interactions

when a drug that is intended for therapeutic uses causes certain harmful effects because of a disease or pre-existing condition the patient has

drug-nutrient interactions

when certain foods or beverages increase or decrease the effects of drugs in the body

drug-herbal interactions

when herbal or dietary supplements increase or decrease a drug's effects

drug-alcohol interactions

occur for two main reasons: alcohol can have chemical reactions with the drug molecule itself, and/or alcohol can have additive harmful side effects with some drugs that are central nervous system (CNS) depressants

drug-laboratory interactions

when drugs interfere with or affect laboratory results