Acidosis tubular renal asociada a intoxicación por trimetoprim-sulfametoxazol

The combination of trimethoprim-sulfamethoxazole (TMP-SMZ or co-trimoxazole) has a bactericidal effect on gram-positive cocci and gram-negative bacilli. It is used clinically for skin and soft tissue, respiratory and urinary tract infections, and is also relevant for prophylaxis and treatment of opportunistic infections in immunosuppressed patients. Its use at established doses in immunocompetent patients is safe, with a low rate of adverse events. However, in immunosuppressed individuals (human immunodeficiency virus [HIV], transplants, or steroid users), the adverse effects (AEs) of this medication reach 83%; and, when administered parenterally at high doses, lactic acidosis has been documented secondary to the polyethylene glycol vehicle. We present two cases of patients who ingested an overdose of TMP-SMZ and developed type 2 renal tubular acidosis (RTA), which has not been described with this medication, and whose hyperlactatemia is not explained by the polyethylene glycol excipient, as it was taken orally