Administration-time-dependent effects of blood pressure-lowering medications: basis for the chronotherapy of hypertension.

There is growing interest on how to best tailor blood pressure (BP)-lowering medications according to the circadian (24 h) BP pattern of individual patients, that is, chronotherapy. Significant and clinically meaningful treatment-time differences in the beneficial and/or adverse effects of at least six different classes of hypertension medications are now known. Generally, calcium channel blockers are more effective with bedtime than morning dosing, and in the case of dihydropyridine derivatives bedtime dosing significantly reduces the risk of edema. Scheduling angiotensin II receptor blockers and angiotensin-converting enzyme inhibitors at bedtime, as opposed to awakening, increases the proportion of patients with properly controlled BP, enhances the sleep-time relative BP decline towards a normal dipping pattern and best reduces urinary albumin excretion, a marker of functional renal status. The chronotherapy of conventional BP-lowering medications entails their correct scheduling with reference to the body's circadian rhythms, not only to achieve control of daytime and night-time systolic and diastolic BP but to normalize the dipping status of the 24 h pattern. Chronotherapy constitutes a cost-effective strategy for enhancing BP control during both nocturnal sleep and daytime activity and for potentially reducing the risk of cardiovascular disease and end-organ injury of the blood vessels and tissue of the heart, brain, kidney, eye and other organs.