Clinical effects and side effects of amrinone. A study of 24 patients with chronic congestive heart failure.

Amrinone, a new inotropic agent, was used to treat 24 patients with chronic congestive heart failure who were classified as clinically stable and who were in New York Heart Association's classes II and III. Patients were treated for up to 30 months (mean, 12.5 months). Exercise tolerance improved in 20 patients, but only eight experienced significant improvement in symptoms of fatigue, dyspnea, and orthopnea and only nine tolerated the drug without apparent side effects. Eight were unable to continue amrinone therapy because of limiting side effects. The most significant adverse effects were cardiac arrhythmias, thrombocytopenia, abnormal results of liver function tests, diarrhea, fever, and nausea. Amrinone has a narrow therapeutic-toxic ratio, but a significant proportion (42%) of patients tolerate and benefit from amrinone therapy.