title: [Clinical chronopharmacokinetics].
abstract: Circadian (approximately or equal to 24 hours) and other endogenous biological rhythms, detectable at all levels of organisation, constitute a temporal structure in all species, including man. Circadian, circannual, and other rhythmic changes in biological susceptibility and response of organisms to a large variety of physical and chemical agents, including medications and foods, are rather common phenomena. A better understanding of periodic and thus predictable changes in drug effects can be attained through consideration of three complementary concepts: the chronopharmacokinetics of a drug (rhythmic changes in its pharmacokinetics), the chronesthesy (rhythmic changes in susceptibility of target biosystems to the drug), and the chronergy (the drug-integrated overall effects). The chronopharmacokinetics of many drugs have been evaluated in man (tables I-IV) including sodium salicylate, aspirin, indomethacin (fig. 1), sustained-release indomethacin, paracetamol (acetaminophen), phenacetin, amidopyrine, theophylline sustained-release theophylline (fig. 2), aminophylline, sustained-release aminophylline, digitalis, propranolol, clorazepate, hexobarbitone (hexobarbital), diazepam, midazolam, lithium, phenytoin (diphenylhydantoin), nortriptyline, ethanol, erythromycine , ampicillin, sulfasymazine , sulphanilamide, cis-diammine-dichloroplatinum (fig. 3), mequitazine (fig. 4), d-xylose, ferrous sulphate, potassium chloride, hydrocortisone and prednisolone, among others. The roles presumably played by circadium rhythms in drug metabolizing liver enzymes (fig. 5), and kidney function are summarized, and the practical implications of chronopharmacokinetics, aiming both to improve in a quantitative manner the metabolic fate of a drug and its effectiveness, are discussed.
mesh_terms: D000758:Anesthesia; D000818:Animals; D001798:Blood Proteins / Q000378:metabolism; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002940:Circadian Rhythm; D004435:Eating; D006801:Humans; D007668:Kidney / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D010507:Periodicity; D004364:Pharmaceutical Preparations / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D001798:Blood Proteins; D004364:Pharmaceutical Preparations
vernacular_title: Chronopharmacocinétique clinique.