Martin Middeke

Comparison of the efficacy and safety of losartan (50-100 mg) with the T-type calcium channel blocker mibefradil (50-100 mg) in mild to moderate hypertension.

Abstract— The objective of this study was to compare the antihypertensive efficacy and safety of losartan and mibefradil. 324 outpatients (57 ± 9.2 years) with mild to moderate hypertension were randomly allocated in a double‐blind fashion to receive 50 mg of losartan or mibefradil once daily p.o. for 6 weeks after 2 weeks of placebo run‐in. Titration was then forced to 100 mg of losartan or mibefradil for an additional 6 weeks. Patients were assessed at baseline, 6 and 12 weeks. The primary efficacy variable was change in predose sitting diastolic (SDBP) and systolic (SSBP) blood pressure at 12 weeks. Secondary variables included change in mean 24‐hour ambulatory blood pressure and comparison of safety and tolerability. Both treatments lowered SSBP and SDBP at 6 and 12 weeks (week 6: mibefradil −14/−9 mm Hg; losartan −12/−7 mm Hg) (p < 0.001). The primary objective, a difference between treatments in reduction of SSBP and SDBP at week 12 could be demonstrated (mibefradil −22/−16 mm Hg; losartan −16/−10 mm Hg) (p = 0.003 and P = 0.001, respectively). Twenty‐four‐hour SBP and 24‐hour DBP were reduced (p < 0.001) within each treatment group at weeks 6 and 12. The secondary objective, a difference between treatments in reduction of 24‐hour blood pressure at week 12 could be demonstrated (P < 0.001). Twenty‐four‐hour heart rate was lowered in the mibefradil group at weeks 6 and 12 (P < 0.001). Responder rates at 6 and 12 weeks were 56.2% and 78.5% for mibefradil versus 56.1% and 55.3% for losartan (P = 0.001). Both treatments were equally well tolerated. This study demonstrates that 50 mg losartan is comparably effective to 50 mg mibefradil in the treatment of mild to moderate hypertension with 100 mg mibefradil being more potent than losartan.