Labetalol and pindolol in the treatment of hypertension: a comparative study.

Labetalol, a new hypotensive drug with both alpha- and beta-adrenoceptor antagonist properties, was compared with pindolol in a double blind cross-over study lasting 15 weeks. Both drugs caused a significant drop on blood pressure in both the standing and the supine position. The effect was seen after only two weeks treatment. The effect on the pulse rate was moderate. Three patients on pindolol (but none on labetalol) had to withdraw from the trial for medical reasons. In general the side effects recorded for labetalol and pindolol were mild. No postural hypotension was noticed with the moderate doses used in the study. Labetalol seems to be at least as effective as pindolol in mild to moderate hypertension.