The authors have investigated the hemodynamic changes accompanying the hypotension that occasionally follows administration of amine oxidase inhibitors, particularly iproniazid phosphate. Iproniazid was given intravenously and orally, in varying doses, to hospitalized patients with toxemia of pregnancy or with essential hypertension associated with pregnancy. Similar observations were made with carboxazid, an analogue of iproniazid. Data on blood pressure in supine and upright positions and on renal hemodynamics and cardiac output indicated that the hypotension was probably caused by venous pooling and by a decrease in the cardiac output rather than by a true vasodilator action.
Assali NS, Dasgupta K. HYPOTENSIVE EFFECTS OF IPRONIAZID AND CARBOXAZID. JAMA. 1960;173(14):1549-1552. doi:10.1001/jama.1960.03020320029008