[Chronopharmacology].

Chronopharmacology studies the influence of time of administration of drugs. Numerous studies have report on the influence of time of administration on acute toxicity of drugs. Qualitative and quantitative responses of the organism to drugs have been described in different areas such as anaesthesiology, cardiology, oncology, endocrinology, gastroenterology, obstetrics, neurology, pneumology, psychiatry, rheumatology... in animals and in men. Underlying mechanisms of such variations involve temporal variations of the mode of action of the drug i.e. at the receptor level or temporal modifications of the kinetics of the drug. Absorption, distribution and drug protein binding, metabolism and elimination vary according to the moment of administration of the drug. Chronotherapy consists on the choice of the moment of administration of a drug in order to minimise its side effects and/or to emphasize its therapeutic effects.