Evaluation of verapamil in the treatment of hypertension.

Two separate randomized double-blind, crossover trials were carried out in hypertensive patients to evaluate the antihypertensive efficacy and safety of verapamil. In the first study, verapamil, in doses of 120 mg three times daily, was compared with pindolol, in doses of 7.5 mg twice daily. A thiazide diuretic was given with both drugs. In another study, verapamil, in doses of 160 mg twice daily, was compared with 200 mg twice daily of labetalol in hypertensive patients with coexisting chronic obstructive lung disease. Blood pressure fell equally with these drugs, and neither of the drugs caused significant side effects. Labetalol significantly reduced both forced expiration volume at 1s (FEV1) and forced vital capacity (FVC), suggesting a bronchoconstrictor effect. Verapamil was devoid of any such effect. Verapamil did not affect plasma renin concentration.