Inclusion Criteria

Concurrent Medication:

Allowed:

• Antiretrovirals.
• PCP prophylaxis.
• IVIG, G-CSF, and erythropoietin.

Concurrent Treatment:

Allowed:

• Transfusions.

Patients must have:

• Localized mucocutaneous herpes simplex OR undisseminated varicella or zoster.
• HIV positive. NOTE: Varicella patients must NOT have AIDS.
• CD4 count >= 100 cells/mm3 (herpes simplex or zoster patients) OR >= 250 cells/mm3 (varicella patients).
• BSA > 0.6 m2.
• Ability to swallow solid dosage formulations.

Prior Medication:

Allowed:

• Prior VZV immune globulin and/or IVIG.
• Antiretrovirals if at a stable dose for at least 14 days.

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms or conditions are excluded:

• Clinical evidence of pneumonitis.
• Severe abdominal pain or back pain.
• Encephalopathy.
• Hemorrhagic varicella.
• Zoster involving ophthalmic branch of trigeminal nerve.
• Severe gastrointestinal disorder.

Concurrent Medication:

Excluded:

• Agents with potential activity against HSV or VZV, such as acyclovir, famciclovir, ganciclovir, foscarnet, and sorivudine.
• Probenecid.
• Aspartamine within 48 hours prior to pharmacokinetic samplings.

Patients with the following prior conditions are excluded:

• Grade 2 creatinine value within the past 30 days.
• Grade 3 hematologic or hepatic values within the past 30 days.
• Prior hypersensitivity and/or allergic reaction to acyclovir.
• Grade 3 or 4 mental status changes within the past 30 days.

Prior Medication:

Excluded:

• Acyclovir within 1 week prior to study entry.
• Steroids within 4 weeks prior to onset of varicella lesions.