[Ambulatory measurement of blood pressure and efficacy of diltiazem. Influence of the timing of drug ingestion and initial blood pressure level].

Clinical and 24-hour ambulatory measurements were made in 46 patients with mild to moderate essential hypertension in order to confirm that the efficacy and safety of sustained-release diltiazem LP 300 mg were the same regardless of the time of day at which it was taken. After two weeks of placebo, patients were randomly assigned double-blind to take diltiazem LP 300 mg either morning or evening for four weeks. Diltiazem LP 300 mg significantly lowered diastolic and systolic blood pressure in both groups by clinical or 24-hour ambulatory measurement, and without any difference according to whether diltiazem LP 300 mg was administered morning or evening. A lesser fall in blood pressure during the night in both groups led to study of the effect of diltiazem LP 300 mg according to initial ambulatory diastolic blood pressure level. Diltiazem brought about a greater fall in blood pressure when patients had an ambulatory diastolic pressure of 90 mmHg or more. Clinical, laboratory and electrocardiographic parameters were all satisfactory, regardless of the time at which the drug was taken.