Pamatolol: phase I evaluation of the pharmacodynamics of a cardioselective beta adrenoceptor blocking drug.

A Phase I evaluation of a new adrenoceptor blocker, pamatolol, was performed in 10 healthy male volunteers. Minor reductions in standing and exercise and isoproterenol-induced increases in heart rate were observed with the 10-mg oral dose and appeared maximal with the 400-600 mg dose. The rate of decline of effect averaged 1.5% of the exercise heart rate/hr. Neither resting systolic time intervals nor post-exercise pulmonary function was affected by this dose range of pamatolol. Based on the latter responses and the isoproterenol dose response curve, we tentatively conclude that pamatolol is relatively cardioselective in man.