Advances in human chronopharmacology

Area of Science:

• Chronobiology
• Pharmacology
• Biomedical Science

Background:

• Biological systems exhibit predictable rhythms influencing susceptibility and response to various agents.
• Chronopharmacology investigates how drug effects vary with biological timing and impact rhythm characteristics.
• Circadian rhythms (approximately 24-hour cycles) significantly influence drug efficacy and toxicity in humans.

Purpose of the Study:

• To summarize documented circadian chronopharmacologic facts in humans.
• To introduce new concepts for understanding chronopharmacologic findings: chronokinetics, chronesthesy, and chronergy.
• To highlight the goal of drug optimization through chronopharmacology, enhancing efficacy while reducing adverse effects.

Main Methods:

• Review and summarization of existing literature on chronopharmacology.
• Documentation of circadian changes in the effects of various chemical agents.
• Extension of studies beyond 24-hour rhythms to include longer biological cycles (e.g., monthly, yearly).

Main Results:

• Circadian variations in the effects of numerous agents including histamine, corticosteroids, and insulin are documented.
• New concepts like chronokinetics (drug bioavailability and excretion rhythms), chronesthesy (biosystem susceptibility rhythms), and chronergy (overall drug effect rhythms) are proposed.
• Metabolic pathways and drug fate are not constant but vary with biological time, impacting drug efficacy.

Conclusions:

• The chronobiologic approach to pharmacology offers a reduced risk of errors compared to conventional homeostatic models.
• Optimizing drug administration timing based on biological rhythms can enhance therapeutic outcomes.
• Future research should focus on integrating chronobiologic principles for personalized and more effective drug therapies.