title: Milrinone and dobutamine in severe heart failure: differing hemodynamic effects and individual patient responsiveness.
abstract: Milrinone and dobutamine were compared in 15 patients with New York Heart Association functional class III and IV congestive heart failure. Dobutamine and milrinone were administered intravenously according a graded titration schedule up to maximum doses (14 micrograms/kg/min and 75 micrograms/kg, respectively) or until increased ventricular ectopy or a reduction in left ventricular end-diastolic pressure to 10 mm Hg or less occurred. Although both agents markedly increased cardiac index, milrinone caused a significantly greater reduction in left and right heart filling pressures and mean arterial pressure than did dobutamine, and for any given increase in dP/dt, milrinone caused a greater reduction in systemic vascular resistance than did dobutamine. Thus, the hemodynamic effects of milrinone are best represented by a combination of the actions of dobutamine, a positive inotropic agent, and a vasodilator such as nitroprusside, which causes both arterial and venous dilation. The positive inotropic responses of individual patients to dobutamine (5 micrograms/kg/min) and milrinone (25 micrograms/kg) were compared. The increases in dP/dt with both agents were variable, and correlated poorly (r = .50; p = .059). Patients were divided into two groups: Group I consisted of eight patients in whom the ratio of the increase in dP/dt with dobutamine vs milrinone was greater than 1.0 (good dobutamine responders); group II consisted of seven patients in whom this ratio was less than 1.0 (poor dobutamine responders).(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D004280:Dobutamine / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D005260:Female; D006333:Heart Failure / Q000188:drug therapy*; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020105:Milrinone; D009200:Myocardial Contraction / Q000187:drug effects; D009599:Nitroprusside / Q000494:pharmacology; D009638:Norepinephrine / Q000097:blood; D011728:Pyridones / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D013268:Stimulation, Chemical; D014655:Vascular Resistance / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
chemical_list: D002316:Cardiotonic Agents; D011728:Pyridones; D009599:Nitroprusside; D004280:Dobutamine; D020105:Milrinone; D009638:Norepinephrine