Diclofenac can impair kidney function by reducing prostaglandin synthesis, which is crucial for blood flow in the kidneys. Patients with kidney issues should have regular kidney function tests.

Diclofenac may worsen renal function in patients with existing kidney disease by affecting prostaglandin-mediated renal blood flow. Monitoring of serum creatinine and BUN levels is advised.

In patients with renal conditions, diclofenac can lead to further renal impairment by decreasing prostaglandin production, which maintains renal perfusion. Regular monitoring of renal function is essential.