Adults: Patients with Herpes Simplex (except herpes encephalitis) Infections: 5 mg/kg body weight IV infusion infused at a constant rate over a 1 hr period every 8 hrs (15 mg/kg/day) for 7 days in patients with normal renal function. Severe Initial Episodes of Herpes Simplex Genitalis: The same dosages as previously mentioned are administered for 5 days.
Immunocompromised Patients with Varicella Zoster Infection: 10 mg/kg body weight over 1 hr period every 8 hrs for 7 days, with provided renal function is not impaired.
Herpes Simplex Encephalitis and Has No Renal Impairment: 10 mg/kg body weight infused at a constant rate over 1 hr period every 8 hrs for 10 days, with provided renal function is not impaired.
Children: The dose of Zovirax IV for infusion for children 3 months to 12 years is calculated on the basis of body surface area.
Herpes Simplex Infection: 250 mg/m2 infused at a constant rate over a 1 hr period every 8 hrs (750 mg/m2) for 7 days.
In Immunocompromised Children with Varicella Zoster Infection: 500 mg/m2 over a 1 hr period every 8 hrs for 7 days.
Children in 6 months to 12 years With Herpes Simplex Encephalitis: More accurate dosing is achieved by infusing 500 mg/m2 at a constant rate over at least 1 hr every 8 hrs for 10 days.
Children with impaired renal function require an appropriately modified dose, according to the degree of impairment.
Elderly: In the elderly, total aciclovir body clearance declines in parallel with creatinine clearance. Special attention should be given to dosage reduction in elderly patients with impaired creatinine clearance.
Renal Impairment: Caution is advised when administering Zovirax IV for infusion to patients with impaired renal function. The following adjustments in dosage are suggested as follows:
Creatinine clearance (CrCl) >50 mL/min: 5 or 10 mg/kg body weight should be given every 8 hrs.
CrCl 25-50 mL/min: 5 or 10 mg/kg body weight every 12 hrs.
CrCl 10-25 mL/min: 5 or 10 mg/kg body weight every 24 hrs.
0 (anuric)-10 mL/min: In Patients Receiving Continous Ambulatory Peritoneal Dialysis (CAPD): 5 or 10 mg/kg body weight should be halved and administered every 24 hrs. In patients receiving haemodialysis 5 or 10 mg/kg body weight should be halved and administered every 24 hrs and after dialysis.