Oral
- Primary herpes simplex infections 200 mg 5 times/day for 5-10 days.
- Suppression of recurrent herpes simplex 800 mg/day in 2-4 divided doses.
- Prophylaxis of herpes simplex in immunocompromised patients 200-400 mg 4 times/day.
- Varicella zoster 800 mg 5 times/day for 5-7 days.
- Herpes zoster 800 mg 5 times/day for 7-10 days.
- Buccal recurrent herpes labialis: apply 1 tab as a single dose to the upper gum region w/in 1 hr of onset of prodromal symptoms.

IV
- Prophylaxis of herpes simplex in immunocompromised patients; 1st episodes of genital herpes 5 mg/kg 8 hrly for 5-7 days.
- Herpes simplex encephalitis 10 mg/kg 8 hrly for 10 days.
- Varicella zoster 5 mg/kg 8 hrly.

Topical/cutaneous
- Herpes simplex infections of skin: 5% oint/cream - apply 5 or 6 times/day for 5-10 days.
- Ophth herpes simplex keratitis: 3% oint - apply 5 times/day until 3 days after healing.

Adverse drug reactions: increased serum bilirubin and liver enzymes, haematological changes, rashes, fever, headache, dizziness, GI effects, hepatitis, jaundice, angioedema, reversible neurological effects, diffuse hair loss; local reactions, inflammation.

See reference for details.

Adapted from CIMS Drug Information System. Internet. Accessed on January 10, 2016.