ABSTRACT:
Hypertension is associated with increased cardio and cerebrovascular morbidity and mortality; antihypertensive drugs have been shown to reduce the risk of adverse cardio and cerebrovascular events. These events tend to be more common during the morning hours, a time when both normo and hypertensives show a circadian peak in blood pressure (BP). Although clinicians have a number of safe and well-tolerated antihypertensive agents in various classes and formulations at their disposal, few are designed to specifically attenuate the morning BP surge while maintaining 24-h efficacy. In the treatment of hypertension, investigation of chronobiology, chronopharmacology and chronotherapy began a few decades ago. Studies over the last decade have revealed that blood pressure (BP) and CVD are influenced by our behavior such as what we eat and even conditioned by the time of day. Also, the ability of the night day ratio of systolic BP predicts the risk for cardiovascular events more accurately compared with office BP measured only at once. Evidence clearly points to the fact that nocturnal BP is indeed the BP as it is most consistently correlated with prediction of cardiovascular risk and provides more close surveillance of safety. Circadian rhythm is a significant input into the regulation of BP. Hence, a circadian disorder such as hypertension requires chronopharmacotherapy. However, different medications have been studied for their chronopharmacology and potential chronotherapy. This article reviews the chronobiology of hypertension and the chronopharmacology and chronotherapy of the Diltiazem hydrochloride used in its management.