Maintenance therapy for cytomegalovirus retinitis in patients with acquired immunodeficiency syndrome: foscarnet.

The use of ganciclovir in the treatment of cytomegalovirus (CMV) retinitis in patients with acquired immunodeficiency syndrome (AIDS) is limited by marrow toxicity and by the development of resistance to this agent in CMV strains capable of causing progressive disease. Foscarnet retains activity against ganciclovir-resistant CMV and has an adverse effect profile different from that of ganciclovir. Preliminary data from studies conducted under the AIDS Clinical Trials Group (ACTG) program indicate that intravenous foscarnet maintenance therapy at 60, 90, and 120 mg/kg/day in AIDS patients with CMV retinitis successfully completing foscarnet induction therapy is associated with median times to retinitis progression of 90, 95, and greater than 123 days, respectively. An ACTG trial of foscarnet in patients failing ganciclovir therapy has been initiated, as has a trial jointly sponsored by the National Eye Institute and the National Institute of Allergy and Infectious Diseases comparing the safety and efficacy of foscarnet and ganciclovir. Also underway is a trial evaluating the effects of combination and alternating regimens of these two agents.