COX-2 inhibitors and the kidney. 
Prostaglandins produced by the COX-2 isoform of cyclooxygenase may be important for renal function--and perhaps even more so in diseases that render the kidney highly prostaglandin-dependent.  COX-2 inhibitors may thus have much the same renal risks that a standard NSAID does.  Several clinical trials have already focused on the new drugs' renal effects.