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Zovirax Injection Dosage

Medically reviewed by Drugs.com. Last updated on May 2, 2022.

Generic name: acyclovir sodium
Dosage form: for Injection

CAUTION—RAPID OR BOLUS INTRAVENOUS INJECTION MUST BE AVOIDED (see WARNINGS and PRECAUTIONS).

INTRAMUSCULAR OR SUBCUTANEOUS INJECTION MUST BE AVOIDED (see WARNINGS).

Therapy should be initiated as early as possible following onset of signs and symptoms of herpes infections.

A maximum dose equivalent to 20 mg/kg every 8 hours should not be exceeded for any patient.

Dosage

Herpes Simplex Infections: Mucosal and Cutaneous Herpes Simplex (HSV-1 and HSV-2) Infections in Immunocompromised Patients

Adults and Adolescents (12 years of age and older)

5 mg/kg infused at a constant rate over 1 hour, every 8 hours for 7 days.

Pediatrics (Under 12 years of age)

10 mg/kg infused at a constant rate over 1 hour, every 8 hours for 7 days.

Severe Initial Clinical Episodes of Herpes Genitalis

Adults and Adolescents (12 years of age and older)

5 mg/kg infused at a constant rate over 1 hour, every 8 hours for 5 days.

Herpes Simplex Encephalitis

Adults and Adolescents (12 years of age and older)

10 mg/kg infused at a constant rate over 1 hour, every 8 hours for 10 days.

Pediatrics (3 months to 12 years of age)

20 mg/kg infused at a constant rate over 1 hour, every 8 hours for 10 days.

Neonatal Herpes Simplex Virus Infections (Birth to 3 months)

10 mg/kg infused at a constant rate over 1 hour,every 8 hours for 10 days. In neonatal herpes simplex infections, doses of 15 mg/kg or 20 mg/kg (infused at a constant rate over 1 hour every 8 hours) have been used; the safety and efficacy of these doses are not known.

Varicella Zoster Infections

Zoster in Immunocompromised Patients

Adults and Adolescents (12 years of age and older)

10 mg/kg infused at a constant rate over 1 hour, every 8 hours for 7 days.

Pediatrics (Under 12 years of age)

20 mg/kg infused at a constant rate over 1 hour, every 8 hours for 7 days.

Obese Patients

Obese patients should be dosed at the recommended adult dose using Ideal Body Weight.

Patients with Acute or Chronic Renal Impairment

Refer to DOSAGE AND ADMINISTRATION section for recommended doses, and adjust the dosing interval as indicated in Table 5.

Table 5. Dosage Adjustments for Patients with Renal Impairment

Creatinine Clearance

(mL/min/1.73 m2)

Percent of

Recommended Dose

Dosing Interval

(hours)

>50

100%

8

25 - 50

100%

12

10 - 25

100%

24

0 - 10

50%

24
Hemodialysis

For patients who require dialysis, the mean plasma half-life of acyclovir during hemodialysis is approximately 5 hours. This results in a 60% decrease in plasma concentrations following a 6-hour dialysis period. Therefore, the patient’s dosing schedule should be adjusted so that an additional dose is administered after each dialysis.

Peritoneal Dialysis

No supplemental dose appears to be necessary after adjustment of the dosing interval.

Method of Preparation

Each 10-mL vial contains acyclovir sodium equivalent to 500 mg of acyclovir. The contents of the vial should be dissolved in 10 mL of Sterile Water for Injection.

The resulting solution contains 50 mg acyclovir per mL (pH approximately 11). Shake the vial well to assure complete dissolution before measuring and transferring each individual dose. The reconstituted solution should be used within 12 hours. Refrigeration of reconstituted solution may result in the formation of a precipitate which will redissolve at room temperature.

DO NOT USE BACTERIOSTATIC WATER FOR INJECTION CONTAINING BENZYL ALCOHOL OR PARABENS.

Administration

The calculated dose should then be removed and added to any appropriate intravenous solution at a volume selected for administration during each 1-hour infusion. Infusion concentrations of approximately 7 mg/mL or lower are recommended. In clinical studies, the average 70-kg adult received between 60 and 150 mL of fluid per dose. Higher concentrations (e.g., 10 mg/mL) may produce phlebitis or inflammation at the injection site upon inadvertent extravasation. Standard, commercially available electrolyte and glucose solutions are suitable for intravenous administration; biologic or colloidal fluids (e.g., blood products, protein solutions, etc.) are not recommended.

Once diluted for administration, each dose should be used within 24 hours.

Frequently asked questions

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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