Описание
Trimethoprim impairs renal potassium excretion and may inhibit tubular secretion of tacrolimus, collectively increasing the risk of hyperkalemia and tacrolimus nephrotoxicity.
Механизм
Trimethoprim blocks the epithelial sodium channel (ENaC) in the distal nephron, reducing potassium secretion; tacrolimus independently reduces GFR and promotes hyperkalemia. Trimethoprim may also mildly inhibit P-gp-mediated tacrolimus renal elimination.
Клиническое значение
Case reports and retrospective analyses in transplant patients show clinically significant hyperkalemia (K⁺ >6.0 mEq/L) and acute kidney injury when trimethoprim or TMP-SMX is added to tacrolimus.
Тактика ведения
Monitor serum potassium and creatinine within 3–5 days of starting trimethoprim; consider alternative antibiotics (e.g., azithromycin, doxycycline for susceptible organisms) when feasible in tacrolimus-treated transplant recipients.
Медицинский отказ от ответственности
This content is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making medication decisions.