THE DOPAMINE CONGENER, IBOPAMINE, IN CONGESTIVE HEART-FAILURE

The hemodynamic effects of the dopamine congener, ibopamine, were investigated in 9 patients with chronic congestive heart failure. A placebo-controlled design was used. Placebo and ibopamine in doses of 100, 200 and 300 mg were given orally as a single dose on 4 successive days. Dopamine at 1, 2, 4 and 6 .mu.g/kg per min i.v. was the internal standard. Ibopamine did not significantly change heart rate, systemic and pulmonary arterial pressures, pulmonary capillary wedge pressure or mean right atrial pressure. Ibopamine doses of 200 and 300 mg significantly decreased systemic arterial resistance (19%), total pulmonary arterial resistance (21%), and significantly increased cardiac index (20%) and stroke volume index (16%). Peak effects occurred at 1-2 h with a duration of action of less than 4 h. The 2 changes were comparable with those obtained by dopamine 2-4 .mu.g/kg per min. Except for mild changes at 30 min postdosing, the inotropic indices of the systolic time intervals were not altered significantly by ibopamine. Ibopamine elicits significant hemodynamic effects in patients with chronic congestive heart failure; these effects appear to be largely mediated through vasodilatory properties rather than direct positive inotropy.