Comparative investigation of the respiratory and cardiovascular effect of mepindolol, propranolol and pindolol in asthmatic patients.

In a controlled double-blind crossover trial of 5 mg mepindolol versus 80 mg propranolol, 15 mg pindolol or placebo given as single oral doses in 16 asthmatic patients, respiratory function and cardiovascular parameters were measured simultaneously. The doses chosen of the 3 active drugs were almost equipotent as shown by the similarity in the percentage fall in pulse rates at 2 hr after ingestion, although it was observed that propranolol had a different time course of effect from the 2 other beta blockers. The effect on respiratory function was marked for propranolol, with statistically significant falls in FEV1 and FEV3 at all times; mild for pindolol with lesser falls which were statistically significant only at nearly 3 hr post-ingestion; and intermediate for mepindolol. Mepindolol gave rise to a rapid and statistically significant fall in lying diastolic blood pressure compared to control values; the reductions in diastolic B. P. for propranolol or pindolol were not statistically significant compared to pretreatment control values.