Single Daily Dosing of Gentamicin: Pharmacokinetic Comparison of Two Dosing Methodologies for Postpartum Endometritis

[摘要] Objective:We compared the pharmacokinetics of two methods for dosing gentamicin for the treatment of postpartum endometritis with the goal of achieving adequate peak serum concentrations (>12 mg/L) and prolonged trough levels below 2 mg/L.Methods:Group-I subjects (n = 5) received intravenous gentamicin, 5 mg/kg per total body weight over 60 min., with a maximum dose of 500 mg. Group-II subjects (n = 17) were dosed intravenously according to the followingformula: Dose = desired peak concentration (fixed at 14 mg/L)*(volume of distribution, i.e., 0.35 L/kg)* adjusted body weight (in kilograms).Serum gentamicin levels were obtained 1 hr. and 8–12 hr. after infusion of thesecond dose. Pharmacokinetic parameters for the subjects in each group were calculatedaccording to standard formulas.Results:Subjects in Group I had significantly higherdoses and peak drug concentrations (P< 0.01), while in Group II, 76% ofpatients had peak levels less than desired (<12 mg/L). Both groups maintained troughlevels of <2 mg/L in excess of 12 hr.Conclusions:Changing to the adjusted body weight formula for Group I,while maintaining a dose between 4 and 5 mg/kg, would reduce excessive peak concentrations.Using a calculated volume of distribution of 0.4 L/kg in Group II would improve peak serumconcentrations to the desired levels. Both dosing regimens ensure adequate aminoglycosidepharmacokinetic parameters and avoid the need for monitoring serial serum drug concentrations,provided the expected clinical response is also achieved. While the first dosing formula is simplerto calculate, the second dosing formula allows for more individualized dosingconsiderations. Infect. Dis. Obstet. Gynecol. 7:133–137, 1999.

[学科分类] 妇产科学