Tobramycin dosing in the puerperal patient

Abstract

Serum levels of tobramycin were determined with an enzyme immunoassay technique in 20 puerperal women with postcesarean endometritis who were being treated with metronidazole-tobramycin. Ideal dosing was then calculated to attempt to provide peak serum levels between 5 and 8 micrograms/mL and trough serum levels less than 2 micrograms/mL. In eight patients, therapeutic serum levels could not be attained even at doses greater than the package-insert recommendation of 3 mg/kg/d. Therapeutic levels were achieved in five patients with doses between 3 and 5 mg/kg/d and in seven patients only at doses above the maximum recommended daily dose of 5 mg/kg. The puerperal patient appears to usually require much higher dosages of tobramycin than usual, and serum levels must be monitored for therapeutic reasons rather than for toxicity.