Systemic and coronary haemodynamic effects of the new hypotensive drug L 6150

The acute systemic and coronary haemodynamic effects of a new hypotensive drug L 6150 (3-hydrazino-6-[N,N-bis(2-hydroxyethyl)amino]pyridazine) have been studied in six patients with renal or essential hypertension. The drug, administered intravenously at a dose of 2-9 mg, caused a marked hypotension and increase of cardiac output in five cases. Though left ventricular work was reduced or unchanged after the drug, myocardial blood flow increased markedly, coronary resistance decreased and coronary A-V oxygen difference decreased by about 50% indicating coronary vasodilation. When compared with the available data on the effects of hydrazinophthalazine, L 6150 appeared to have qualitatively similar effects, but a somewhat greater direct coronary vasodilator effect.