Tacrolimus and Trimethoprim Sulfamethoxazole: Drug Interaction Guide
Quick answer: This combination requires caution. Tacrolimus and Trimethoprim Sulfamethoxazole can be used together with adjustments and monitoring.
How Tacrolimus interacts with Trimethoprim Sulfamethoxazole
Trimethoprim inhibits tubular secretion of creatinine and potassium and acts as an epithelial sodium channel blocker, causing additive nephrotoxicity and hyperkalaemia with tacrolimus.
What you should do
Monitor renal function and serum potassium weekly during therapy; reduce dose or change antibiotic if creatinine rises >30% or potassium >5.5 mmol/L.
Key facts
Severity
Moderate — caution required
Mechanism
Trimethoprim inhibits tubular secretion of creatinine and potassium and acts as an epithelial sodium channel blocker, ca...
Action
Monitor renal function and serum potassium weekly during therapy; reduce dose or change antibiotic if creatinine rises >...
Frequently asked questions
Can I take Tacrolimus and Trimethoprim Sulfamethoxazole together?
With caution. Monitor renal function and serum potassium weekly during therapy; reduce dose or change antibiotic if creatinine rises >30% or potassium >5.5 mmol/L.
What is the severity of this interaction?
The interaction between Tacrolimus and Trimethoprim Sulfamethoxazole is classified as Moderate — caution required. Trimethoprim inhibits tubular secretion of creatinine and potassium and acts as an epithelial sodium channel blocker, causing additive nephrotoxicity and hyperkalaemia with tacrolimus.
What should I do if I'm prescribed both?
Monitor renal function and serum potassium weekly during therapy; reduce dose or change antibiotic if creatinine rises >30% or potassium >5.5 mmol/L. Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.