Chapter 2: Basic Principles of Drug Action and Drug Interactions

Percutaneous

Absorbed through the skin and mucous membranes Inhalation, sublingual, or topical

Parenteral

Bypasses the GI tract by using subcutaneous, intramuscular, and intravenous injection

Excretion

Depends on GI tract and kidneys

Distribution

Depends on circulation to be transported throughout body

Metabolism

Depends on enzyme systems

Absorption

Depends on route of administration Drug is transferred from entry site into the body's circulating fluids Absorption rate depends on route, blood flow, and solubility of the drug Subcutaneous and intramuscular injection absorption is affected by circulation Intravenous medications are absorbed fastest Topical medications applied to the skin can be influenced by skin thickness and hydration

Liberation

Drug released from dosage form and is dissolved in body fluid Process of converting oral drug can be influenced by food and water in the stomach

Antagonist

Drugs that attach to a receptor but do not stimulate a response

Agonists

Drugs that interact with a receptor to stimulate a response

LADME

Liberation Absorption Distribution Metabolism Excretion

Drug receptors

Specific sites where drugs form chemical bonds

Pharmacodynamics

Study of interactions between drugs and their receptors and the series of events that result in a pharmacologic response

Enteral

Via the gastrointestinal tract by the oral, rectal, or nasogastric routes

All drugs are processed in the body through pharmacokinetics. What is the correct order that drugs pass through the body? a)Liberation, absorption, distribution, metabolism, excretion b)Distribution, metabolism, liberation, absorption, excretion c)Biotransformation, liberation, distribution, absorption, excretion d)Excretion, distribution, liberation, absorption, metabolism

a)Liberation, absorption, distribution, metabolism, excretion