Summary: Amlodipine, a potent long-acting dihydropyridine calcium antagonist, was compared with placebo in a parallel, randomized, double-blind study in 134 patients with chronic stable angina pectoris maintained on betaadrenergic blocking agents. After a single-blind, two-week placebo period, patients were randomized to receive either amlodipine (2.5, 5, and 10 mg) or placebo once daily for four weeks. The effects of amlodipine on maximal exercise time, work, time to angina onset, and subjective indices including angina frequency, nitroglycerin tablet consumption, and patient and investigator ratings were assessed. Each dose of amlodipine produced increases in exercise time and calculated total work accomplished compared to baseline. Improvements at 5 and 10 mg were significantly greater than placebo which produced no significant change (p < 0.05). Qualitative improvements in the severity of angina were produced by amlodipine at 5 and 10 mg daily assessed by patient-rating questionnaires (pc0.05). Reductions in angina frequency attacks per week and weekly nitroglycerin tablet consumption occurred but were not statistically significant when cornpared with placebo. Adverse effects observed during amlodipine treatment prompted discontinuation of treatment in only 2 out of 100 patients. Three patients discontinued treatment for reported lack of efficacy. No laboratory abnormalities prompted treatment discontinuation and minor side effects of dizziness, nausea, headache, and fatigue were observed infrequently. The results of this controlled, large-scale multicenter trial suggest that amlodipine significantly increased exercise capacity and was well tolerated when added to the antianginal regimen of patients remaining symptomatic while receiving beta-blocking agents.
The efficacy and safety of once-daily dosing of isradipine, a new calcium antagonist vasodilator, was evaluated in a multicenter, placebo-controlled trial in hypertensive patients who had supine diastolic blood pressure (SDBP) 100-119 mm Hg. After a 3-week single-blind placebo washout patients randomly received either isradipine, 5 mg once daily, or a matching placebo; if SDBP remained greater than or equal to 95 mm Hg or less than or equal to 10 mm Hg below baseline at four weekly clinic visits, isradipine was increased at weekly intervals by 5 mg once daily up to 20 mg and maintained during weeks 5 and 6. At week 6 mean supine blood pressure 24 hours after dosing had declined from 163 +/- 20/105 +/- 5 (N = 78) to 146 +/- 17/92 +/- 7 mm Hg (N = 60) on isradipine, 14.5 mg once daily, and from 163 +/- 20/105 +/- 6 (N = 85) to 157 +/- 18/99 +/- 10 mm Hg (N = 64) on placebo (P less than .001 between groups). Standing blood pressure decreased from 159 +/- 20/104 +/- 8 to 144 +/- 18/93 +/- 11 mm Hg with isradipine and from 160 +/- 22/105 +/- 9 to 154 +/- 19/101 +/- 11 mm Hg with placebo (P less than .001 between groups) without signs or symptoms of postural hypotension. A SDBP less than or equal to 90 mm Hg or a greater than or equal to 10 mm Hg fall below baseline was achieved in 41 of 78 isradipine-treated (53%) and 18 of 85 placebo-treated subjects (21%).(ABSTRACT TRUNCATED AT 250 WORDS)
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