Celecoxib × Tacrolimus

Celecoxib (a selective COX-2 inhibitor) reduces renal blood flow via prostaglandin suppression. Tacrolimus is nephrotoxic in its own right. Additive acute kidney injury risk, especially with borderline renal function.

Reduced urine output, rising creatinine and potassium, fluid retention, raised blood pressure. The risk is higher in older patients, in impaired renal or liver function or heart failure, and with diuretics, angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers.

Avoid using tacrolimus with drugs known to harm the kidneys, including non-steroidal anti-inflammatory drugs (NSAIDs) such as celecoxib (tacrolimus SmPC). If celecoxib cannot be avoided, monitor renal function and other adverse effects and adjust the tacrolimus dose if needed (tacrolimus SmPC); renal function must be monitored with this combination (celecoxib SmPC). The US Food and Drug Administration (FDA) also advises monitoring renal function and tacrolimus blood concentrations when tacrolimus is used with nephrotoxic drugs (US tacrolimus label). NSAIDs are highly bound to plasma proteins, so check tacrolimus trough concentrations and adjust the dose if needed (tacrolimus SmPC). Measure blood pressure at the start of celecoxib and during treatment (celecoxib SmPC).