Comparison of Nitrendipine Combined with Low-Dose Hydrochlorothiazide to Hydrochlorothiazide Alone in Mild to Moderate Essential Hypertension

Abstract

Patients with mild to moderate essential hypertension were treated in four centers with hydrochlorothiazide (HCTZ) 25 mg daily for 4 weeks. Those patients failing to achieve control (supine diastolic blood pressure (DBP) 90 mm Hg or lower) were randomly assigned to nitrendipine (NTP) 5 mg or placebo (PLA) b.i.d. NTP or PLA was increased stepwise to 20 mg b.i.d. as needed to achieve control. Treatment with HCTZ was maintained at 25 mg daily. Eighty-six patients completed the study: 41 in NTP + HCTZ and 45 in PLA + HCTZ groups. Both groups were comparable in baseline characteristics. Supine systolic blood pressure (SBP) was 148.6 +/- 14.4 and DBP was 96.0 +/- 5.4 mm Hg in the NTP + HCTZ group. SBP was 147.4 +/- 16.6 and DBP was 96.4 +/- 5.6 mm Hg in the PLA + HCTZ group. At the end of 7 weeks of titration and treatment with NTP or PLA combined with HCTZ, SBP had fallen to 133.4 +/- 15.1 and DBP to 85.4 +/- 5.9 mm Hg in the NTP + HCTZ group. SBP fell to 138.8 +/- 16.2 and DBP to 90.7 +/- 6.3 mm Hg in the PLA + HCTZ group. The increment in lowering of both SBP and DBP was significantly greater (p = 0.002 and p = 0.0007, respectively) in the NTP + HCTZ group compared to the PLA + HCTZ group.