Posology : מינונים

4.2   Posology and method of administration
Route of administration: Slow intravenous infusion over 1 hour.
A course of treatment with Zovirax I.V. usually lasts 5 days, but this may be adjusted according to the patient's condition and response to therapy. Treatment for herpes encephalitis usually lasts 10 days. Treatment for neonatal herpes infections usually lasts 14 days for mucocutaneous (skin-eye-mouth) infections and 21 days for disseminated or central nervous system disease.
The duration of prophylactic administration of Zovirax I.V. is determined by the duration of the period at risk.
Dosage in adults:
Patients with Herpes simplex (except herpes encephalitis) or Varicella zoster infections should be given Zovirax I.V. in doses of 5 mg/kg body weight every 8 hours provided renal function is not impaired (see Dosage in renal impairment).
Immunocompromised patients with Varicella zoster infections or patients with herpes encephalitis should be given Zovirax I.V. in doses of 10 mg/kg body weight every 8 hours provided renal function is not impaired (see Dosage in renal impairment).
In obese patients dosed with intravenous aciclovir based on their actual body weight, higher plasma concentrations may be obtained (see 5.2 Pharmacokinetic properties).
Consideration should therefore be given to dosage reduction in obese patients and especially in those with renal impairment or the elderly.
Dosage in infants and children:
The dose of Zovirax I.V. for infants and children aged between 3 months and 12 years is calculated on the basis of body surface area.
Infants and children 3 months of age or older with Herpes simplex (except herpes encephalitis) or Varicella zoster infections should be given Zovirax I.V. in doses of 250 mg per square metre of body surface area every 8 hours if renal function is not impaired.
In immunocompromised children with Varicella zoster infections or children with herpes encephalitis, Zovirax I.V. should be given in doses of 500 mg per square metre body surface area every 8 hours if renal function is not impaired.
The dosage of Zovirax I.V. in neonates and infants up to 3 months of age is calculated on the basis of body weight.
The recommended regimen for infants treated for known or suspected neonatal herpes is aciclovir 20 mg/kg body weight IV every 8 hours for 21 days for disseminated and CNS disease, or for 14 days for disease limited to the skin and mucous membranes.
Infants and children with impaired renal function require an appropriately modified dose, according to the degree of impairment (see Dosage in renal impairment).


Dosage in the elderly:
The possibility of renal impairment in the elderly must be considered and dosage should be adjusted accordingly (see Dosage in renal impairment below).
Adequate hydration should be maintained.
Dosage in renal impairment:
Caution is advised when administering Zovirax I.V. to patients with impaired renal function. Adequate hydration should be maintained.
Dosage adjustment for patients with renal impairment is based on creatinine clearance, in units of ml/min for adults and adolescents and in units of ml/min/1.73m2 for infants and children less than 13 years of age. The following adjustments in dosage are suggested:
Dosage adjustments in adults and adolescents:
Creatinine Clearance                       Dosage
25 to 50 ml/min                            The dose recommended above (5 or 10 mg/kg body weight) should be given every 12 hours.
10 to 25 ml/min                              The dose recommended above (5 or 10 mg/kg body weight) should be given every 24 hours.
0(anuric) to 10 ml/min                       In patients receiving continuous ambulatory peritoneal dialysis (CAPD) the dose recommended above (5 or 10 mg/kg body weight) should be halved and administered every 24 hours.


In patients receiving haemodialysis the dose recommended above (5 or 10 mg/kg body weight) should be halved and administered every 24 hours and after dialysis.


Dosage adjustments in infants and children:
Creatinine Clearance                         Dosage
25 to 50 ml/min/1.73m2                       The dose recommended above (250 or
500 mg/m2 body surface area or 20 mg/kg body weight) should be given every 12 hours.


10 to 25 ml/min/1.73m2                       The dose recommended above (250 or 500 mg/m2 body surface area or 20 mg/kg body weight) should be given every 24 hours.


0(anuric) to 10 ml/min/1.73m2                In patients receiving continuous ambulatory peritoneal dialysis (CAPD) the dose recommended above (250 or
500 mg/m2 body surface area or 20 mg/kg body weight) should be halved and administered every 24 hours.
In patients receiving haemodialysis the dose recommended above (250 or 500 mg/m2 body surface area or 20 mg/kg body weight) should be halved and administered every 24 hours and after dialysis