title: Papaverine disposition in cardiac surgery patients and the effect of cardiopulmonary bypass.
abstract: Cardiac surgery involving cardiopulmonary bypass (CPB) causes substantial physiologic changes which may potentially alter the pharmacokinetic properties of drugs used during and after the procedure. Studies with fentanyl have implied a relationship between prolonged elimination half-lives following CPB and decreased liver perfusion during and after the procedure. To further test this hypothesis, the effects of CPB on the pharmacokinetics of papaverine, a coronary vasodilator currently being added to the cardioplegic solution to prevent vasospasm, were studied. The drug was given to two groups of patients, one (n = 6) undergoing surgery with and one (n = 5) without CPB, the latter serving as controls. Plasma papaverine concentrations declined biexponentially in the control patients with a mean elimination half-life of 1.30 +/- 0.25 h, total plasma clearance of 13.8 +/- 3.75 ml/min/kg, volume of distribution of 1.52 +/- 0.45 l/kg and volume of distribution, steady-state, of 0.992 +/- 0.530 l/kg. For the CPB group, only half-life was estimated, and averaged 2.77 +/- 0.28 h, significantly greater (p less than 0.01) than that in the controls. These results further confirm the increased half-lives seen with other hepatically cleared drugs following CPB and have implications in the clinical management of patients given drugs eliminated in this manner.
mesh_terms: D000328:Adult; D000368:Aged; D000758:Anesthesia; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D005260:Female; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D010208:Papaverine / Q000378:metabolism*
chemical_list: D010208:Papaverine