Varicella zoster virus infections - 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.
CrCl ≥50 mL/min 1,000 mg tds;
30-49 mL/min 1,000 bd;
10-29 mL/min 1,000 mg once daily;
10 mL/min 500 mg once daily.
Herpes simplex virus (HSV) Immunocompetent adult & adolescent ≥12 yr (CrCl ≥30 mL/min) 500 mg bd;
CrCl <30 mL/min 500 mg once daily.
Immunocompromised adult (CrCl ≥30 mL/min) 1,000 mg bd for at least 5 days;
CrCl <30 mL/min 1,000 mg once daily.
Herpes labialis Immunocompetent adult & adolescent (CrCl ≥50 mL/min) 2,000 mg bd for 1 day. Take 2nd dose about 12 hr (no sooner than 6 hr) after the 1st dose;
CrCl 30-49 mL/min 1,000 mg bd in 1 day;
10-29 mL/min 500 mg bd in 1 day;
<10 mL/min 500 mg single dose.
Suppression of recurrences of HSV infections Immunocompetent adult & adolescent ≥12 yr (CrCl ≥30 mL/min) 500 mg once daily. For immunocompetent subjects w/ a history of ≥10 recurrences/yr, better results may be obtained w/ 250 mg bd.
CrCl <30 mL/min
250 mg once daily.
Immunocompromised adult ≥30 mL/min 500 mg bd;
CrCl <30 mL/min 500 mg once daily.
Prophylaxis of cytomegalovirus infection & disease Adult & adolescent ≥12 yr (CrCl ≥75 mL/min) 2,000 mg qds, to be initiated as early as possible post-transplant;
CrCl 50 to <75 mL/min 1,500 mg qds;
25 to <50 mL/min 1,500 mg tds;
10 to <25 mL/min 1,500 mg bd;
<10 mL/min or on dialysis 1,500 mg once daily.
Patients on intermittent haemodialysis Give the dose after dialysis on dialysis days.
Childn The efficacy in childn <12 yr has not been evaluated.
Elderly Adjust dose accordingly.
Hepatic impairment Dose modification is not required.