Propranolol kinetics in patients submitted to cardiac surgery with cardiopulmonary bypass
© The Author(s) 2001
Published: 26 June 2001
Propranolol plasma levels and pharmacokinetics (PK) may be altered by cardiopulmonary bypass (CPB). Propranolol kinetic disposition was investigated in patients submitted to myocardial revascularization with mild hypothermic cardiopulmonary bypass (HCPB).
Fifteen patients receiving propranolol pre-(30-120 mg/day) and postoperatively (5-10 mg/day) were evaluated. Propranolol plasma levels were measured before, during and after surgery using high-performance liquid chromatography. PK modelling based on one compartment open model was applied to data obtained after drug administration (propranolol, tablets) 1 day before surgery and at the first postoperative day.
Plasma levels indicate propranolol mobilization, probably due to stress and surgical trauma, since the beginning up to the end of hypothermic cardiopulmonary bypass. The influence of HCPB on pharmacokinetics of propranolol was demonstrated by the three times prolongation of t1/2β and Vd/F increased by two times. Additionally, plasma levels increase could be justified by plasma clearance reduction.
An accumulation of propranolol might be expected in patients submitted to cardiac surgery with hypothermic cardiopul-monary bypass and lower doses of this drug could be required during the postoperative period.