Comparative effect of intravenous administration of atenolol and practolol on resting and exercise-evoked increase in heart rate and cardiac work load in normal human subjects.

A comparative study of the intensity and duration of action of intravenously administered single doses of atenolol and practolol on the resting and exercise-evoked increase in heart rate and rate-pressure product was carried out in six normal human subjects. On a weight to weight basis, atenolol was 8 times more potent than practolol. There were only marginal differences in the intensity and duration of action of the two drugs. Atenolol, like practolol, was well-tolerated and no side effects were observed. If found safe on longterm use, atenolol may be a suitable alternative to practolol. The daily administration of atenolol in two divided doses should suffice for therapeutic purposes.