THERMOGENIC EFFECT OF AMRINONE IN HEALTHY-MEN

Objectives: The thermogenic effect of amrinone is unknown and its util ization in patients with severe cardiac failure could. potentially inc rease oxygen requirements and therefore aggravate oxygen debt. Consequ ently, the present study was undertaken to assess the thermogenic resp onse to amrinone at three different plasma concentrations under contro lled conditions and to analyze amrinone's effects on various biochemic al variables. Design: A prospective, unblinded, controlled study. The initial control period was followed by three sequential, experimental treatments. Subjects: Ten young, healthy, male volunteers with normal body weight. Interventions: Three experimental periods. Amrinone was a dministered intravenously in progressive doses: a) 0.5 mg/kg followed by 5 mu g/ kg/min; b) 0.5 mg/kg followed by 10 mu g/kg/min; and c) 1.0 mg/kg followed by 10 mu g/kg/min. Measurements and Main Results: Oxyg en consumption (Vo(2)) and CO2 production were continuously measured b y means of a computerized indirect calorimeter. At the highest dose, a mrinone produced a slight and significant (p < .01) increase in Vo(2) and in resting metabolic rate (+ 4.5% and + 3.7%, respectively), while no change in CO2 production or in respiratory quotient occurred throu ghout the study. At the medium and high doses, amrinone increased plas ma free fatty acid concentrations by 38% and 53%, respectively (p < .0 5). No variation in plasma glucose, lactate, insulin, norepinephrine, or epinephrine concentrations was observed during the study. Conclusio ns: Amrinone administered intravenously at therapeutic doses has minim al thermogenic and metabolic effects in humans without cardiac failure .