A comparison of amlodipine, verapamil and placebo in the treatment of mild to moderate hypertension. Amlodipine Study Group.

This is a double blind parallel group comparison in patients with mild-moderate hypertension, of amlodipine, verapamil and placebo. One hundred and sixty patients entered the double blind phase. In the amlodipine group the mean supine and standing systolic pressures at week 12 were respectively lowered from baseline by 11.9 mmHg and 11.3 mmHg more than for the placebo group (P = 0.0001). Diastolic blood pressures were also significantly reduced. With verapamil the mean supine and standing systolic blood pressure at week 12 were reduced by 7.7 mmHg and 8.3 mmHg more on verapamil than on placebo (P = 0.0083). Blood pressures of the amlodipine group were lower 24 hour post-dose than verapamil 12 hours post dose. The responder rates after eight weeks of double blind therapy were amlodipine 72.3%, verapamil 47.8% and placebo 32.6%. Body weight after verapamil increased by mean 0.9 kg, after amlodipine by 0.2 kg and after placebo decreased by 0.2 kg. Six patients were withdrawn because of adverse effects (3 amlodipine, 2 verapamil, 1 placebo). The number of patients with adverse effects possibly related to therapy were 22/53 for amlodipine, 19/54 for verapamil and 14/53 for placebo. Both drugs were, overall, well tolerated, effective and had no unexpected adverse effects.