Herpes zoster & ophth zoster Immunocompetent adult 1,000 mg tds for 7 days.
Immunocompromised adult 1,000 mg tds for at least 7 days & for 2 days following crusting of lesions.
HSV infections Immunocompetent adult & adolescent ≥12 yr 500 mg bd for 10 days (initial episodes) or 3-5 days (recurrent episodes).
Immunocompromised adult 1,000 mg bd for at least 5 days or 10 days (initial episodes).
Herpes labialis (cold sore) Adult & adolescent Initially 2,000 mg bd for 1 day. 2nd dose to be taken 12 hr after 1st dose.
Suppression of recurrences of HSV infections Immunocompetent adult & adolescent ≥12 yr 250 mg bd.
Immunocompromised adult 500 mg bd.
Prophylaxis of CMV infection & disease Adult & adolescent ≥12 yr 2,000 mg qds for 90 days but may need to be extended in high-risk patients. All doses to be reduced according to CrCl.