An Open-Label Study of the Safety and Efficacy of Cidofovir for the Treatment of Relapsing Cytomegalovirus Retinitis in Patients With AIDS

Inclusion Criteria Concurrent Medication: Allowed: * Antiretroviral agents. * Oral trimethoprim/sulfamethoxazole. * Aerosolized pentamidine. * Dapsone. * Fluconazole. * Rifabutin. * Filgrastim (G-CSF). * Itraconazole. * HIV vaccines. Patients must have: * AIDS. * CMV retinitis, with severity as specified in the Disease Status field. * Life expectancy of at least 3 months. * Consent of parent or guardian if less than 18 years of age. Exclusion Criteria Co-existing Condition: Patients with the following symptoms or conditions are excluded: * Known clinically significant allergy to probenecid. * Clinically significant cardiac disease, including symptoms of ischemia, congestive heart failure, or arrhythmia. * Other active medical problems sufficient to hinder study compliance. Concurrent Medication: Excluded: * Amphotericin B. * Aminoglycoside antibiotics. * Vidarabine. * Intravenous pentamidine. * CMV hyperimmune immunoglobulin. * Other nephrotoxic or potentially nephrotoxic agents. * Other investigational agents with anti-CMV activity. * Ganciclovir. * Intravenous or oral acyclovir (except following development of herpetic lesion). * Foscarnet. * Diuretics. Prior Medication: Excluded within 2 days prior to study entry: * Ganciclovir or foscarnet. Excluded within one week prior to study entry: * Amphotericin B. * Aminoglycoside antibiotics. * Vidarabine. * Intravenous pentamidine. * CMV hyperimmune immunoglobulin. * Other nephrotoxic agents. * Other investigational agents with anti-CMV activity. Excluded at any time: Prior systemic or intravitreal HPMPC. Drug or alcohol abuse that is considered sufficient to hinder study compliance.