Drug interactions between Bextra and Viread

GENERALLY AVOID: Coadministration of tenofovir with other nephrotoxic agents may increase the risk and severity of nephrotoxicity due to additive effects on the kidney. Additionally, renal impairment secondary to the use of these agents may reduce the clearance of tenofovir, which is primarily eliminated by renal excretion. The use of tenofovir has been associated with dose-related nephrotoxicity including cases of acute renal failure and Fanconi syndrome characterized by renal tubular injury with severe hypophosphatemia. Generally, the risk is low in patients with adequate renal function receiving the normally recommended dosage but may increase in patients with underlying renal impairment. MANAGEMENT: The use of tenofovir in patients who have recently received or are receiving treatment with other potentially nephrotoxic agents (e.g., aminoglycosides, polypeptide and polymyxin antibiotics, vancomycin, amphotericin B, adefovir, cidofovir, foscarnet, cisplatin, gallium nitrate, lithium, mesalamine, certain immunosuppressants, intravenous bisphosphonates, intravenous pentamidine, high intravenous dosages of methotrexate, high dosages of nonsteroidal anti-inflammatory agents) should generally be avoided. Renal function should be evaluated prior to and during therapy with tenofovir. Patients with renal insufficiency at baseline or during treatment may require dosage adjustment in accordance with the manufacturer's product labeling.