Twenty-four hour ambulatory blood pressure profile of a new slow-release formulation of diltiazem in mild to moderate hypertension.

Twelve patients with a mild to moderate essential hypertension were included in a double-blind, balanced, randomized placebo-controlled cross-over study to assess the efficacy and duration of action of a new slow-release formulation of diltiazem (300 mg) given once daily for 3 weeks. All office blood pressure measurements were done 24 hours after drug intake. In order to improve the accuracy of the trial, 24-hours non-invasive ambulatory blood pressure monitoring (Spacelabs 90207 system) were performed as well. Diltiazem significantly lowered supine and standing systolic and diastolic office blood pressure (by 16.9/12.7 mmHg and by 17.3/13.8 mmHg, respectively), without changing office heart rate. Diltiazem also significantly lowered ambulatory blood pressure measured over 24 hours, as well as ambulatory heart rate. The blood pressure lowering effect was most pronounced during the daytime period and did not reach statistical significance during the sleeping hours. The treatment was well tolerated, and there were no significant side effects. The results confirm the antihypertensive efficacy of diltiazem LP 300 mg once daily during the daytime and during the early morning blood pressure rise, without inducing nocturnal hypotension.