Pethidine clearance during continuous intravenous infusions in postoperative patients.

1 Pethidine pharmacokinetics in ten female patients during continuous i.v. infusion for 32 h post-surgery have been determined. 2 The blood clearance of pethidine (mean +/- 2.d.) measured directly was 599 +/- 135 ml/min and is in marked contrast to some reported values. 3 Other model-dependent pharmacokinetic parameters were consistent with previously reported values. 4 Pethidine and indocyanine green clearance were correlated but the correlation was mediated through body weight. 5 Pethidine clearance and steady state concentration were predictable retrospectively from linear multivariable equations involving simple physical characteristics of the patient.