Effects of nilvadipine and amlodipine in patients with mild to moderate essential hypertension: a double blind, prospective, randomised clinical trial

Abstract

Objective: This double blind, prospective, randomised, parallel group clinical trial was aimed at investigating the effects of nilvadipine or amlodipine in mild to moderate hypertensive patients over a 3-month treatment period.

Research design and methods: Eligible outpatients (supine DBP > or = 90 mmHg and < or = 110 mmHg and supine SBP < or = 180 mmHg) entered a maximum 15-day placebo run-in period and were randomised to receive once daily nilvadipine 8 mg or amlodipine 5 mg (to be doubled in the case of lack of response at day 30). Follow-up visits with measurement of supine and orthostatic blood pressure and heart rate were performed after 15, 30, 60 and 90 days of treatment. Standard laboratory tests and 12-lead ECG were performed at study entry and at the end of treatment; adverse events were collected at any time.

Results: A total number of 168 patients, 83 in the nilvadipine and 85 in the amlodipine group, took part in the study: 15 and 14 in the two groups, respectively, were prematurely withdrawn. Supine DBP at endpoint similarly decreases in the two groups (-11.0 +/- 7.1 mmHg in the nilvadipine group and -12.7 +/- 8.2 mmHg in the amlodipine group), with no significant differences between groups at any time point. Measurements in the orthostatic position also did not show between-groups differences. Blood pressure was normalised in 61.8% of patients in the nilvadipine group and in 63.0% in the amlodipine group; responders to therapy were 64.5% and 69.1% in the two groups, respectively. Results of SBP also did not show differences between groups at any time point, except a more marked decrease in the amlodipine group compared to nilvadipine in the supine measurements at endpoint. A total number of 30 patients (36.6%) in the nilvadipine group and 23 (27.1%) in the amlodipine group reported adverse events (p = 0.24 between groups), which mainly consisted of vasodilatory effects (e.g. oedema, flushing and headache). A favourable lipid profile, i.e. a significant (p = 0.002 between groups) decrease of triglycerides levels and an increase of HDL-C, was observed in the nilvadipine group, compared with an increase of triglycerides in the amlodipine group. No effects on haematology, liver and renal function were observed in either group.

Conclusions: Nilvadipine or amlodipine produced comparable effects on DBP and shared a similar adverse effect profile. A favourable effect on lipid profile was observed following nilvadipine treatment.