Chronopharmacology & Chronotherapeutics

Chronopharmacology & Chronotherapeutics

1. Definition and therapeutic purpose

• Chronopharmacology studies the relationship between drug effects and circadian rhythm. It adds the biological time of administration to the usual questions of which drug, which dose and which route to use. Padmaja introduces the subject through daily variation in disease activity and examples of timed treatment. (Padmaja 7e Ch.5, pp.73–74)
• Chronotherapeutics applies that relationship to treatment by arranging drug administration or drug exposure in relation to a relevant biological rhythm. (Padmaja 7e Ch.5, pp.73–74)
• Three useful purposes emerge from the textbook examples: approximate physiological hormone secretion, inhibit a process when its activity is greater, or provide treatment before the expected period of symptoms. Morning glucocorticoids, evening short-acting statins and night-time antihistamines illustrate these respective purposes. (Padmaja 7e Ch.5, pp.73–74; KDT 8e Ch.46, p.684)
• Timing is one component of an individualised regimen. The prescribed dose must still account for the desired response, drug potency, pharmacokinetics and patient variability; KDT emphasises adjusting treatment according to the response of the individual patient. A plausible timing rationale by itself does not establish a clinically superior regimen. (KDT 8e Ch.5, pp.71, 73, 77)