Pharmacodynamic studies in man of theβ-adrenoceptor antagonist DL 071 IT

DL 071 IT, a new potent non-selectiveβ-adrenergic blocking drug with intrinsic sympathomimetic activity and weak membrane stabilizing activity, was evaluated alone and in comparison with oxprenolol, in six volunteers, at rest and during an exercise test. Heart rate and systolic pressure were monitored for up to 7 h after oral administration of the drugs. Exercise heart rate and systolic pressure were significantly reduced by both drugs, but only DL 071 IT caused a significant reduction in resting heart rate. As compared to oxprenolol, DL 071 IT has a longer duration of action and is from 5.0 to 13.5 times more potent.