ANTIHYPERTENSIVE EFFICACY OF A SLOW-RELEASE NIFEDIPINE TABLET FORMULATION GIVEN ONCE-DAILY IN PATIENTS WITH MILD-TO-MODERATE HYPERTENSION -A PLACEBO-CONTROLLED, DOUBLE-BLIND PARALLEL-GROUP TRIAL

In a double-blind, randomized parallel-group, multicenter study the an tihypertensive efficacy of a slow release tablet containing 60 mg nife dipine (Aprical long(R), CAS 21829-25-4) has been investigated. After two-weeks wash-out of previous antihypertensive medication and a two-w eeks placebo run-in period, 88 patients of both gender with a diastoli c blood pressure between 95 and 115 mmHg received either nifedipine or placebo for 8 weeks. Blood pressure was measured at the end of the do se interval at real by a semi-automatic, auscultatory device. Control measurements were recorded using a standard cuff sphygmomanometer. Pri mary efficacy criterion was the drop in diastolic blood pressure (DBP, measured semi-automatically) after 8 week therapy. 88 patients were r andomized to nifedipine or placebo. 86 patients completed the protocol (42 nifedipine, 44 placebo). However, only in 73 patients BP measurem ents were recorded appropriately with the semi-automatic device (36 ni fedipine, 37 placebo). In the nifedipine group, blood pressure fell fr om 152 (+/- 18) / 102 (+/- 6) mmHg to 139 (+/- 16) / 91 (+/- 10) mmHg. Blood pressure under placebo was determined to 149 (+/- 20) / 102 (+/ - 8) mmHg before treatment and 146 (+/- 18) / 100 (+/- 10) mmHg at the end of the study. Heart rate was not affected under both treatments. The 90% confidence interval of the difference between the mean fall in DBP ranged from 5.0 to 12.5 mmHg, the point estimator was 8.8 mmHg. A t the end of the study, 21 of 36 patients under nifedipine and 10 of 3 7 patients under placebo had a DBP below 90 mmHg and/or a decrease in DBP > 10 mmHg. The results show that a clinically relevant reduction o f DBP can be achieved in a considerable number of patients under treat ment with the slow release preparation under investigation in a once d aily regimen.