The pharmacokinetics of cotrimoxazole sulphonamide in malnourished (marasmic) infants.

The pharmacokinetics of trimethoprim-sulphamethoxazole was examined in seven malnourished (marasmic) infants receiving cotrimoxazole (CMZ) for treatment of urinary tract infection. Comparisons were made with the SMZ level of ten nutritionally normal infants, hospitalized for first and second degree burns, receiving CMZ for treatment of bronchitis. CMZ was administered as an oral suspension (20 mg TMP and 100 mg SMZ, 5 ml), patients receiving 22 mg SMZ/kg body weight. Capillary blood samples, 0.05 ml were taken at prescribed intervals. Elimination half-life of SMZ in the marasmic infants was prolonged, 9.6 vs 4.9 hr, in their eutrophic counterparts. In addition, greater area under the curve (AUC), 573 vs 328 micrograms/ml/h, was noted in the malnourished group. This disparity may be due to differences in body fluid distribution between the two groups.