Cidofovir Dihydrate

INDICATION AND USAGE Cidofovir injection is indicated for the treatment of CMV retinitis in patients with acquired immunodeficiency syndrome (AIDS). THE SAFETY AND EFFICACY OF CIDOFOVIR INJECTION HAVE NOT BEEN ESTABLISHED FOR TREATMENT OF OTHER CMV INFECTIONS (SUCH AS PNEUMONITIS OR GASTROENTERITIS), CONGENITAL OR NEONATAL CMV DISEASE, OR CMV DISEASE IN NON-HIV-INFECTED INDIVIDUALS. DESCRIPTION OF CLINICAL TRIALS Three phase II/III controlled trials of cidofovir injection have been conducted in HIV-infected patients with CMV retinitis.

ADVERSE REACTIONS Nephrotoxicity: Renal toxicity, as manifested by ≥2+ proteinuria, serum creatinine elevations of ≥0.4 mg/dL, or decreased creatinine clearance ≤55 mL/min, occurred in 79 of 135 (59%) patients receiving cidofovir injection at a maintenance dose of 5 mg/kg every other week. Maintenance dose reductions from 5 mg/kg to 3 mg/kg due to proteinuria or serum creatinine elevations were made in 12 of 41 (29%) patients who had not received prior therapy for CMV retinitis (Study 106) and in 19 of 74 (26%) patients who had received prior therapy for CMV retinitis (Study 107). Prior foscarnet use has been associated with an increased risk of nephrotoxicity; therefore, such patients must be monitored closely (see CONTRAINDICATIONS , WARNINGS , DOSAGE AND ADMINISTRATION ).

Pregnancy Teratogenic Effects: Pregnancy Category C Cidofovir was embryotoxic (reduced fetal body weights) in rats at 1.5 mg/kg/day and in rabbits at 1 mg/kg/day, doses which were also maternally toxic, following daily intravenous dosing during the period of organogenesis. The no-observable-effect levels for embryotoxicity in rats (0.5 mg/kg/day) and in rabbits (0.25 mg/kg/day) were approximately 0.04 and 0.05 times the clinical dose (5 mg/kg every other week) based on AUC, respectively.

WARNING RENAL IMPAIRMENT IS THE MAJOR TOXICITY OF CIDOFOVIR INJECTION. CASES OF ACUTE RENAL FAILURE RESULTING IN DIALYSIS AND/OR CONTRIBUTING TO DEATH HAVE OCCURRED WITH AS FEW AS ONE OR TWO DOSES OF CIDOFOVIR INJECTION. TO REDUCE POSSIBLE NEPHROTOXICITY, INTRAVENOUS PREHYDRATION WITH NORMAL SALINE AND ADMINISTRATION OF PROBENECID MUST BE USED WITH EACH CIDOFOVIR INFUSION. WARNINGS Nephrotoxicity Dose-dependent nephrotoxicity is the major dose-limiting toxicity related to cidofovir injection administration. Cases of acute renal failure resulting in dialysis and/or contributing to death have occurred with as few as one or two doses of cidofovir injection. Renal function (serum creatinine and urine protein) must be monitored within 48 hours prior to each dose of cidofovir injection. Dose adjustment or discontinuation is required for changes in renal function (serum creatinine and/or urine protein) while on therapy. Proteinuria, as measured by urinalysis in a clinical laboratory, may be an early indicator of cidofovir injection -related nephrotoxicity. CONTRAINDICATIONS Initiation of therapy with cidofovir injection is contraindicated in patients with a serum creatinine >1.5 mg/dL, a calculated creatinine clearance ≤55 mL/min, or a urine protein ≥100 mg/dL (equivalent to ≥2+ proteinuria). Cidofovir injection is contraindicated in patients receiving agents with nephrotoxic potential.