title: Duration of drug action.
abstract: Duration of drug action depends on several factors: the absolute amount of drug given; the pharmaceutical preparation; the reversibility of drug action; the half-life of the drug; the slope of the concentration-response curve; the activity of metabolites, and the influence of disease on drug elimination. The duration of action of a drug with more than one effect may differ, depending on which effect is followed. Drugs with a prolonged therapeutic effect should be given once or twice daily. Drugs with a short duration of therapeutic effect are best given at regular intervals rather than by t.i.d. or q.i.d. regimens.
mesh_terms: D000328:Adult; D000368:Aged; D003692:Delayed-Action Preparations; D004305:Dose-Response Relationship, Drug; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D006801:Humans; D008297:Male; D004364:Pharmaceutical Preparations / Q000008:administration & dosage / Q000378:metabolism; D010600:Pharmacology; D013997:Time Factors
chemical_list: D003692:Delayed-Action Preparations; D004364:Pharmaceutical Preparations