Successful Use of Fludrocortisone for the Management of Trimethoprim–Sulfamethoxazole-Induced Hyperkalemia: A Case Series

Trimethoprim–sulfamethoxazole (TMP–SMX) is a widely used antibiotic for various infections but is often associated with hyperkalemia. In this case series, we evaluate the use of fludrocortisone (FCS), a mineralocorticoid receptor agonist, in managing TMP–SMX-induced hyperkalemia. Six patients treated with TMP–SMX for infectious indications developed hyperkalemia within 2–6 days of therapy initiation. The administration of FCS at doses ranging from 0.1 to 0.2 mg daily effectively stabilized potassium levels in all patients within 1–2 days, allowing most to continue the TMP–SMX treatment. These findings highlight the efficacy of FCS in mitigating TMP–SMX-induced potassium retention, thereby providing a safe and practical approach to maintaining essential antibiotic therapy.