Treatment of Acyclovir-Resistant Mucocutaneous Herpes Simplex Infection in Patients With the Acquired Immunodeficiency Syndrome: A Randomized Multicenter Study of Foscarnet Versus Vidarabine

Inclusion Criteria Concurrent Medication: Allowed for phase B: * Aerosolized pentamidine prophylaxis for Pneumocystis carinii pneumonia (PCP). Prior Medication: Allowed for phase A: * Ganciclovir. Patients receiving this drug at the time of study enrollment must discontinue the drug at the time of enrollment and for the duration of the study period. Exclusion Criteria Co-existing Condition: For phase A, patients with pre-existing severe neurologic impairment such as seizure disorder or marked or incapacitating ataxia are excluded. Concurrent Medication: Excluded upon entry into phase B: * Ganciclovir. * Immunomodulators. * Probenecid. * Ciprofloxacin. * Allopurinol. * Zidovudine (AZT). * Antiretrovirals. * Other investigational agents. * Acyclovir for another labeled indication. * Potentially nephrotoxic agents. Patients will be excluded from the study for the following reasons: Phase A: * Previous hypersensitivity reaction to foscarnet or vidarabine. Patients who have a documented history of vidarabine intolerance may be eligible for the foscarnet on the non-randomized arm of the study. Phase B: * Clinical response to therapy with acyclovir in phase A described as "healed" or "good." Prior Medication: Excluded within 14 days of study entry: * Immunomodulators or biologic response modifiers. Phase A: * Excluded within 30 days of study entry: * Foscarnet. Phase B: Excluded within 7 days of study entry into phase B: * Any potentially nephrotoxic agent, except acyclovir. Prior Treatment: Excluded for phase A within 14 days of study entry: * Lymphocyte replacement therapy. Patients must demonstrate the following clinical and laboratory findings: Phase A: * HIV positive by federally licensed ELISA test confirmed by Western blot, p24 serum antigen, or a positive HIV culture; or a prior diagnosis of AIDS as defined by Centers for Disease Control criteria. * Mucocutaneous herpes simplex virus (HSV) infection confirmed by viral culture persisting for a minimum of 2 weeks which is clinically resistant to therapy with acyclovir in the opinion of the patient's physician. Phase B: * Persistent shedding of HSV at the completion of or within 1 week after completion of phase A acyclovir therapy as confirmed by viral culture. Documented in vitro resistance of the virus to acyclovir. * All strains must be referred to the Diagnostic Virology Laboratories at either San Francisco General Hospital or Beth Israel Hospital, Boston, for susceptibility testing. * Two serum acyclovir levels drawn during phase A. Results may be pending at time of entry into phase B. * All eligibility evaluations must be performed within 7 days prior to study entry for phase A or B.