NEPHROTOXICITY OF GENTAMICIN AND COTRIMOXAZOLE COMBINATION IN RATS

1. The nephrotoxicity of gentamicin is well known. However, little inf ormation is available regarding the combined effects of gentamicin plu s co-trimoxazole (sulfamethoxazole-trimethoprim). Therefore, Wistar ra ts were treated daily with 100 mg/kg gentamicin or 100 mg/kg gentamici n plus 30 mg/kg trimethoprim-150 mg/kg sulfamethoxazole for 14 days. 2 . Serum biochemical parameters were measured on days 0, 8 and 15, and histopathological examinations of kidneys were performed on day 15, on e day following end of treatment. Gentamicin treated rats exhibited a 63% increase in blood urea nitrogen (BUN), a 124% increase in uric aci d, and a 63% decrease in serum potassium levels on day 15. 3. The comb ination of gentamicin plus co-trimoxazole partially ameliorated these effects. With the three drug combination no change occurred in BUN, an d only a 30% decrease occurred in serum potassium levels. 4. While ser um creatinine levels significantly increased following gentamicin, the co-administration of co-trimoxazole resulted in a significant decreas e (30%) in creatinine. Histopathological examinations of kidneys sugge sted a lower degree of nephrotoxicity in rats treated with gentamicin plus co-trimoxazole as compared to animals treated with gentamicin alo ne. 5. The results support the importance of monitoring serum biochemi cal parameters when treating with gentamicin or gentamicin plus co-tri moxazole.