Comparison of the acute hemodynamic effects of ibopamine and dopamine in chronic congestive heart failure.

The acute hemodynamic effects of ibopamine (SB-7505), the 3,4-diisobutyryl ester of N-methyldopamine which can be administered orally, were compared with those of dopamine. Ten male patients aged 54 years on average, with chronic congestive heart failure in NYHA (New York Heart Association) classes II-IV were studied. Eight of them were suffering from idiopathic congestive cardiomyopathy and two from ischemic cardiopathy. Baseline hemodynamic parameters were recorded within 24 h after withdrawal of previous treatment, the patients being kept on digitalis only. The investigation was carried out for a period of 3 days running. On day 1 of treatment one group of 5 patients were given dopamine at increasing doses of 2, 4 and 6 micrograms/kg/min. Their hemodynamic parameters were assessed 15 min after each dose and 15 and 60 min after withdrawal of the drug. Ibopamine was then administered orally in single doses of 50 mg on day 2 and 100 mg on day 3. The hemodynamic parameters were evaluated at 30, 60, 90, 120, 180, 360 and 480 min after administration. On day 1, another group of 5 patients were given 50 mg ibopamine, on day 2, 100 mg ibopamine and on day 3, dopamine. Hemodynamic data in this group of patients were evaluated at the same times mentioned above. The hemodynamic effects of ibopamine 100 mg are very similar to those obtained with 4 micrograms/kg/min dopamine. Indeed, the effects of both drugs on the cardiac index, right atrial pressure, peripheral and pulmonary vascular resistance do not differ significantly from each other.(ABSTRACT TRUNCATED AT 250 WORDS)