The January and February 1999 editions of Drug Therapy were devoted, in part, to the new COX-2 selective non-steroidal anti-inflammatory agents. While there are theoretical advantages of the COX-2 specific drugs in the incidence of gastrointestinal ulceration, other side effects may not be reduced. A recent publication by Swan and colleagues¹ suggests that clinicians need to exercise caution in the use of both rofecoxib (Vioxx) and celecoxib (Celebrex).

Swan and her colleagues examined the effects of rofecoxib on renal function in elderly patients. Two studies were actually performed. The first was a single high-dose study (250mg of rofecoxib and 75mg of indomethacin and placebo) and the second a multiple-dose study of rofecoxib at either 12.5mg or 25mg daily compared with indomethacin at 50mg three times daily for six days or placebo.

Subjects enrolled were between 60 and 80 years of age without significant medical history or concurrent disease. Subjects were fed a specially prepared low-salt diet prior to the study. This low-salt diet was employed in an effort to promote renal dependence on prostaglandin production, according to the authors. Renal function was measured using inulin, iothalamate and creatinine clearance. The data on inulin clearance with single dose are listed below: