Abstract: 
In this review, the concepts of biological rhythms, chronobiology, chronopharmacology, and chronotherapy for various diseases have been discussed. The presence of circadian rhythms in human health and illness has been alluded to since the time of Hippocrates. However, it was not until the 1960’s that a large variety of physiologic functions and biologic rhythms were described. Biologic variations have now been reported for several physiologic processes and play an important role in the manifestation of many illnesses. The past decade has witnessed rapid advances in the field of chronobiology, which are now being incorporated into clinical medicine, pharmacology and pharmacy practice. A number of chronotherapeutic medications, aiming at synchronizing medications and the intrinsic biorhythms of disease have been developed by novel drug delivery technology. In some cases, conventional medications are being administered according to circadian rhythms. This article focuses on biorhythms and the emerging role of chronotherapeutics in optimizing the treatment of several diseases.

Keywords: Biological Rhythms, Chronobiology, Chronotherapeutic, Hippocrates, Circadian Rhythms.