Vistide Disease Interactions

Cidofovir is associated with dose-dependent nephrotoxicity, which is minimized by adequate hydration. One liter of normal saline should be infused over 1 to 2 hours prior to each dose of cidofovir in normal adults. Therapy with cidofovir should be administered cautiously in patients who are dehydrated. These patients may be candidates for an additional liter, given over 1 to 3 hours upon the initiation or completion of cidofovir infusion.

Cidofovir may cause neutropenia (20% in clinical trials). Therapy with cidofovir should be administered cautiously in patients with preexisting neutropenia or those receiving concomitant drugs with myelosuppressive effects. With some drugs (e.g., zidovudine or AZT), a temporary interruption of therapy or a reduction in dosage may be necessary on days of cidofovir administration. Close monitoring of neutrophil count is recommended during therapy with cidofovir. Some patients may be candidates for granulocyte colony stimulating factor.

The initiation of cidofovir therapy is contraindicated in patients with renal impairment defined by a serum creatinine > 1.5 mg/dL, a calculated creatinine clearance <= 55 mL/min, or a urine protein >= 100 mg/dL (i.e., 2+ proteinuria). Cidofovir is associated with dose-dependent nephrotoxicity, which may result in acute renal failure and the need for dialysis in some cases, as well as Fanconi's syndrome. Patients with normal renal function or mild dysfunction should be monitored closely for declining renal function during cidofovir therapy, and the dosing adjusted or discontinued accordingly. Renal function should be assessed within 48 hours preceding each dose.