What is meant by pharmacokinetics?

Pharmacokinetics refers to the study of how drugs are absorbed, distributed, metabolized, and excreted by the body. It involves understanding the factors that can influence the movement of drugs within the body and how these factors can affect drug efficacy and safety.

b. This choice is incorrect because it describes pharmacodynamics, not pharmacokinetics. Pharmacodynamics is the study of how drugs interact with target cells or tissues to produce therapeutic effects.

c. This choice is incorrect because it describes the formulation and delivery of drugs, not their absorption, distribution, metabolism, and excretion. The formulation and delivery of drugs are important aspects of drug development and administration but are not part of pharmacokinetics.

d. This choice is incorrect because it describes the regulation and control of drugs by government agencies, not their absorption, distribution, metabolism, and excretion. The regulation and control of drugs are important aspects of ensuring their safety and efficacy but are not part of pharmacokinetics.

Intravenous administration bypasses first-pass metabolism because drugs are injected directly into the bloodstream, avoiding metabolism in the liver before entering the systemic circulation.

a. Oral administration does not bypass first-pass metabolism because drugs must first pass through the liver before entering the systemic circulation.

c. Sublingual administration partially bypasses first-pass metabolism because some of the drugs is absorbed directly into the bloodstream through the mucous membranes under the tongue, but some may still be swallowed and subject to first-pass metabolism.

d. Rectal administration partially bypasses first-pass metabolism because some of the drugs is absorbed directly into the bloodstream through the rectal mucosa, but some may still be subject to first-pass metabolism.