Coadministration has not been studied but based on metabolism and clearance a clinically significant interaction is unlikely. Celecoxib is metabolised mainly by CYP2C9. The potential for hepatically metabolised interactions with adefovir is low. Adefovir is eliminated renally via glomerular filtration and active renal secretion by OAT1. [Note, use in patients with severe liver impairment is contraindicated in the European SmPC and not recommended in the US Prescribing Information. In patients with moderate liver impairment (serum albumin 25-35 g/L, Child-Pugh Class B), celecoxib treatment should be started at half the recommended dose.]