Trimethoprim-sulfamethoxazole hyperkalemia with

Trimethoprim produces the predictable adverse effects of an antifolate drug, especially megaloblastic anemia, leukopenia, and granulocytopenia. The combination trimethoprim-sulfamethoxazole may cause all of the untoward reactions associated with sulfonamides. Nausea and vomiting, drug fever, vasculitis, renal damage, and central nervous system disturbances occasionally occur also. Patients with AIDS and pneumocystis pneumonia have a particularly high frequency of untoward reactions to trimethoprim-sulfamethoxazole, especially fever, rashes, leukopenia, diarrhea, elevations of hepatic aminotransferases, hyperkalemia, and hyponatremia. 

Alappan R, Perazella MA, BuUer GK. Hyperkalemia in hospitalized patients treated with trimethoprim-sulfamethoxazole. Ann Intern Med 1996 124(3) 316-20. 

Koc M, Bihorac A, Ozener Cl, Kantarci G, Akoglu E. Severe hyperkalemia in two renal transplant recipients treated with standard dose of trimethoprim-sulfamethoxazole. Am J Kidney Dis 2000 36(3) E18. 

Mori H, Kuroda Y, Imamura S, Toyoda A, Yoshida I, Kawakami M, et al. Hyponatremia and/or hyperkalemia in patients treated with the standard dose of trimethoprim-sulfamethoxazole. Internal medicine (Tokyo, Japan). 2003 Aug 42(8) 665-9. 

Funai N, Shimamoto Y, Matsuzaki M, Watanabe M, Tokioka T, Sueoka E, Suga K, Ono K, Sano M, Yamaguchi M. Hyperkalemia with renal tubular dysfunction by sulfamethoxazole-trimethoprim for pneumocystis carinii pneumonia in patients with lymphoid malignancy. Haematologia 1993 25 137-141. 

Hyperkalemia due to high doses of co-trimoxazole (14 mg/kg/day trimethoprim and 70 mg/kg/day sulfamethoxazole) occurred in an HIV-positive patient with P. jiroveci pneumonia (70). 

Life-threatening hjrperkalemia secondary to the use of standard oral doses of co-trimoxazole (trimethoprim 320 mg/day and sulfamethoxazole 1600 mg/day) occurred in a 77-year-old man with moderate chronic renal insufficiency from diabetic nephropathy (71). In addition to hyperkalemia, he developed severe metabolic acidosis both resolved on appropriate medical intervention and withdrawal of co-trimoxazole. 

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