A comparison of once-daily and 8-hour gentamicin dosing in the treatment of postpartum endometritis

Objective: To evaluate whether once-daily gentamicin dosing is as effective as the traditional 8-hour regimen for the treatment of postpartum endometritis. Methods: Postpartum women with endometritis were randomized to receive gentamicin 5 mg/kg as a single daily dose or 1.75 mg/kg every 8 hours. All subjects also received clindamycin. Each participant had a peak serum gentamicin level of at least 5.0 mu g/mL within the first 24 hours. The dosing regimens were compared by analyzing the number of hours that patients were febrile, the length of hospital stay occurrence of complications, pharmacy costs, and nursing time required to administer the regimens. Results: The study group (n = 62) and the control group (n = 65) were similar in demographic characteristics and the presence of endometritis risk factors. No differences were found between the groups in the number of patients who completed therapy without complications, required changes in antibiotics, or required readmission for endometritis. The groups did not differ in the number of hours that patients remained febrile after the start of therapy or in the length of hospital stay. No patient in the study group had an initial peak serum concentration less than 5.0 mu g/mL, whereas 24 patients in the control group had initial peak serum concentrations less than 5.0 mu g/mL and required dose adjustment, a statistically significant difference (P < .001). Pharmacy costs averaged $16.12 +/- 5.68 for the study group and $41.75 +/- 17.41 for the control group, also a significant difference (P < .001). Nurse tasking time averaged 13.62 +/- 2.56 minutes for the study group and 28.06 +/- 8.77 minutes for the control group (P < .001). Conclusion: In patients with postpartum endometritis, once-daily gentamicin dosing provides consistently high peak serum levels of gentamicin, requires less nurse tasking time, costs less, and is as effective as the 8-hour dosing regimen.