Inclusion Criteria

Prior Medication:

Allowed:

• Ganciclovir (DHPG).

Exclusion Criteria

Co-existing Condition:

Patients with the following are excluded:

• Any clinically significant pulmonary or neurologic impairment (e.g., patients who are intubated or comatose).
• Corneal, lens, or vitreous opacification which precludes examination of the fundi, or evidence of tuberculotic, diabetic, and/or hypertensive retinopathy.
• Known allergy to foscarnet.

Concurrent Medication:

Excluded:

• Nephrotoxic drugs.
• Acyclovir.

Patients with the following are excluded:

• Any clinically significant pulmonary or neurologic impairment (e.g., patients who are intubated or comatose).
• Corneal, lens, or vitreous opacification which precludes examination of the fundi, or evidence of tuberculotic, diabetic, and/or hypertensive retinopathy.
• Known allergy to foscarnet.

Prior Medication:

Excluded within 7 days of study entry:

• Immunomodulators.
• Biologic response modifiers.
• Investigational agents (other than ganciclovir).

Patients with AIDS as defined by the CDC, with manifest first episode cytomegalovirus (CMV) retinitis as identified by its characteristic ophthalmoscopic appearance and verified by fundus photography.

• Patients must be able to give informed consent.
• Patients who enter the study because of ganciclovir toxicity will have received ganciclovir therapy which resulted in either absolute neutrophil count falling to < 750 cells/mm3 or platelet count falling to < 50000 platelets/mm3 on two separate occasions during either:
• A ganciclovir induction regimen of 7.5 mg (or more)/kg/day in divided doses.
• A maintenance regimen of 5 mg (or more)/kg/day as a single daily dose.
• Patients who enter the study because of ganciclovir treatment failure will meet one of the following criteria:
• CMV retinitis progression has occurred either 1) at the end of a 10 - 21 day induction course of ganciclovir (7.5 - 10 mg/kg/day in divided doses) or 2) during the first 28 days of maintenance ganciclovir therapy (5 mg (or more)/kg/day, at least 5 days/week) where maintenance therapy began within 1 week of completing induction therapy.