Disposition of cefotaxime and its desacetyl metabolite in morbidly obese male and female subjects.

Cefotaxime sodium (1 g) was injected intravenously in 12 normal (90-110% ideal body weight) and 11 obese (190-210% ideal body weight) male and female subjects. Plasma and urine levels were measured for cefotaxime and its active metabolite desacetylcefotaxime. Kinetic parameters were calculated. Results indicate that a dose adjustment for body weight in obese subjects is not needed, whereas a dose adjustment on the basis of body surface area is reasonable. Metabolite plasma levels in female subjects were significantly higher than in male subjects in both the normal and the obese populations.