Research Journal of Pharmacology and Pharmacodynamics

Chronopharmacology is an emerging field that investigates how the timing of drug administration in relation to biological rhythms particularly circadian rhythms affects pharmacological outcomes. Circadian clocks regulate a wide array of physiological processes, including hormone secretion, metabolism, enzyme activity, and receptor expression, all of which can influence a drug’s absorption, distribution, metabolism, and excretion (ADME). This review explores the molecular basis of circadian rhythms, the mechanisms by which they modulate pharmacokinetics and pharmacodynamics, and their clinical significance across major therapeutic areas such as cardiovascular disease, cancer, asthma, metabolic and psychiatric disorders. Accumulating evidence supports the idea that synchronizing drug administration with the body's internal clock can enhance therapeutic efficacy, reduce toxicity, and improve patient outcomes- a concept known as chronotherapy. However, challenges remain in individual variability, clinical implementation, and the integration of circadian biomarkers in treatment protocols. As personalized medicine advances, chronopharmacology is poised to play a central role in optimizing drug therapy through biologically timed interventions.