pharmacology

Pharmacology is the branch of science that studies how chemical substances interact with living organisms to influence function. It covers the origin, development, and regulation of drugs, including their sources, chemical properties, therapeutic uses, and adverse effects. Pharmacology integrates physiology, biochemistry, and medicine to understand drug action.

Pharmacology is commonly divided into pharmacodynamics and pharmacokinetics. Pharmacodynamics examines how drugs produce effects in the body, including mechanisms of action, receptor interactions, and dose–response relationships. Pharmacokinetics describes the body’s handling of drugs—absorption, distribution, metabolism, and excretion—to determine concentration at action sites.

Subfields include clinical pharmacology, which studies drugs in humans and informs safe and effective use; toxicology, the study of harmful effects; pharmacogenomics, how genetic variation affects drug response; pharmacovigilance, monitoring adverse drug reactions; and pharmacoepidemiology, which analyzes drug use patterns.

Drug discovery and development involve preclinical testing, clinical trials, and regulatory approval before a product can be marketed. Post-marketing surveillance monitors safety in broader populations. Evidence-based guidelines, dosage adjustments, and considerations of drug interactions are central to practice in medicine, pharmacy, and dentistry.

Pharmacology underpins rational prescribing and patient care, facilitating optimized dosing, individualized therapy, and mitigation of risks. It is taught across healthcare disciplines and informs policy, education, and public health regarding safe and effective medication use.