Tropodifene (Tropaphen) is an α-Adrenergic receptor blocking agent. Clinical trials have shown that tropaphen has a beneficial effect on hypertension. Tropaphen has a very marked adrenolytic and vasodilator action. It greatly lowers the tone of the peripheral vessels. The preparation is effective starting with a dose of 0.1 mg/kg. After injection of the drug in a dose of 0.25 mg/kg, a considerable and gradually progressive decrease in the perfusion pressure takes place. The pressure falls by 30-35% and remained at a low level for 90-100 min. With a dose of tropaphen of 0.5 mg/kg, the perfusion pressure falls by 40-45% and remains low for 120 min or more. Strong vasodilatation is also observed after injection of tropaphen into intact rabbits.