A double-blind comparison of verapamil and labetalol in hypertensive patients with coexisting chronic obstructive airways disease.

A randomized, double-blind, cross-over trial was carried out in nine hypertensive patients with coexisting chronic obstructive lung disease to evaluate the hypotensive efficacy and safety of verapamil and labetalol. The effects on respiratory function were also assessed. Verapamil in doses of 160 mg twice daily was equally effective as 200 mg twice daily of labetalol. Labetalol significantly reduced both forced expiration volume at 1 s (FEV1) and forced vital capacity (FVC), suggesting a bronchoconstrictor effect. Verapamil was devoid of any such effect. Neither drug caused significant side effects.