The clinical relevance of chronopharmacology in therapeutics.

Circadian rhythms in the functions of the body are well established, e.g. in cardiovascular (blood pressure, heart rate, blood flow, etc.), pulmonary, hepatic and renal functions. Also the symptoms and the onset of diseases are not randomly distributed within 24 hours of a day (e.g. coronary infarction, angina pectoris attacks, silent ischaemia, asthmatic attacks). Accordingly, the effects and/or pharmacokinetics of drugs can display significant daily variations. Recent data on the chronopharmacodynamics and chronopharmacokinetics of H2-blockers, antiasthmatics (theophylline, beta-agonists, glucocorticoids), cardiovascular active drugs (beta-blockers, organic nitrates, calcium channel blockers, ACE-inhibitors) are described as representative examples. The data demonstrate that biological rhythms can have an impact on drug therapy.