Rapid onset of co-trimoxazole induced interstitial nephritis.

An infant developed anuric renal failure within 18 hours of starting therapy with Co-trimoxazole for otitis media. There was no prior exposure to Co-trimoxazole, sulfonamides or trimethoprim. A renal biopsy revealed acute interstitial nephritis with eosinophilic infiltration (AIN). The lymphocyte blast transformation test revealed increased proliferation of the patient's lymphocytes on exposure to Co-trimoxazole (Bactrim). Both parents have clinically demonstrated hypersensitivity to sulfonamides. The extremely short latent period between ingestion of the offending drug and the onset of AIN in the absence of prior exposure to the drug has been reported previously. It suggests that drug induced AIN may develop more rapidly in patients with a strong genetic hypersensitivity to the drug.