MORNING VERSUS EVENING ADMINISTRATION OF NIFEDIPINE GASTROINTESTINAL THERAPEUTIC SYSTEM IN THE MANAGEMENT OF ESSENTIAL-HYPERTENSION

The nifedipine gastrointestinal therapeutic system (GITS) is a recentl y developed controlled-release formulation for once-a-day dosing. We e valuated the influence of morning versus evening administration of the drug in a randomized double-blind cross-over study including 15 essen tial hypertensives. Five patients had to be excluded from blood pressu re analysis because of noncompliance (three cases) or intolerable side effects (two cases). To assess the exact duration of the antihyperten sive efficacy noninvasive automatic ambulatory blood pressure monitori ng was performed. After a placebo period patients were given 30 mg nif edipine GITS either at 1000 or 2200 hours. Twenty-four-hour systolic a nd diastolic blood pressure profiles documented a sustained antihypert ensive effect of both nifedipine regimens throughout the whole period without affecting the circadian rhythm. Statistical analysis revealed no significant difference between morning and evening administration. Two patients stopped their medication because of intolerable side effe cts (fatigue and muscle cramps, respectively). Two more eases suffered from mild reversible headache which provoked no discontinuation of th e drug. In conclusion our results document a sustained antihypertensiv e efficacy of 30 mg nifedipine GITS in patients with moderate essentia l hypertension. Time of administration has no impact on day- and night time blood pressure control.