Pharmacokinetics and Pharmacodynamics of Olprinone after Cardiac Surgery

摘要

Background Phosphodiesterase type HI inhibitors are often delivered by continuous intravenous infusion without initial loading to prevent hypotension, i.e., by "slow induction". We evaluated the pharmacokinetics (PK) and pharmacodynamics (PD) of olprinone slow induction after open-heart surgery. Methods Olprinone was infused at a rate of 0.2 μg·kg~(-1)·min~(-1) in seven patients post operatively after elective cardiac surgery. Olprinone plasma concentration was determined by HPLC. PK parameters were calculated from concentrations at 90 and 180 minutes after start of infusion. PD data were analyzed by collected E_(max) model using SAAMII~(~R) PC programs. Results Systemic vascular resistance index initially decreased about 20 ng/mL and then cardiac index increased. Initially, a vasodilating effect occurs and then inotropic effect follows. Systemic hypotension may induced by the different EC_(50) between inotropic and vasodilating action. Moreover, much vasodilating effect will be observed with olprinone than with milrinone, based on our previous data. Conclusions Olprinone slow induction is useful and safe for critically ill patients.