Forskolin, A New Inotropic Agent

Abstract

Forskolin is a labdane diterpene obtained from the plant Coleus Forskohlii. Forskolin probably acts by activation of adenylcylase. Forskolin was infused intravenously in patients with low cardiac output, commencing with 0.1 ug/kg/minute in Hemaccel solution. The rate was doubled every 2 minutes to a maximum of 1.6 ug/kg/Min. Ventricular functions was evaluated by a nuclear stethoscope before infusion and 5, 10, 15 and 50 Minutes after stopping the infusion. The cardiovascular parameters included heart rate, systolic blood pressure, diastolic blood pressure, ejection fraction, cardiac output, peak ejection rate, peak filling time and overall filling time. The ejection fraction, in 8 patients, rose from the mean basal value of 23.10± 2037 to 38±3.59(P< 0.001). There were also significant increases in ejection velocity and filling velocity. These effects were seen at a dose of 8–16 ug/kg/10 minutes. No significant chronotropic or barotropic effects were notedo Forskolin was extremely well tolerated at this dose.