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Zovirax Suspension Dosage

Generic name: ACYCLOVIR 200mg in 5mL
Dosage form: oral suspension
Drug class: Purine nucleosides

Medically reviewed by Last updated on Apr 5, 2023.

Acute Treatment of Herpes Zoster

800 mg every 4 hours orally, 5 times daily for 7 to 10 days.

Genital Herpes

Treatment of Initial Genital Herpes

200 mg every 4 hours, 5 times daily for 10 days.

Chronic Suppressive Therapy for Recurrent Disease

400 mg 2 times daily for up to 12 months, followed by re-evaluation. Alternative regimens have included doses ranging from 200 mg 3 times daily to 200 mg 5 times daily.

The frequency and severity of episodes of untreated genital herpes may change over time. After 1 year of therapy, the frequency and severity of the patient’s genital herpes infection should be re-evaluated to assess the need for continuation of therapy with ZOVIRAX.

Intermittent Therapy

200 mg every 4 hours, 5 times daily for 5 days. Therapy should be initiated at the earliest sign or symptom (prodrome) of recurrence.

Treatment of Chickenpox

Children (2 years of age and older)

20 mg/kg per dose orally 4 times daily (80 mg/kg/day) for 5 days. Children over 40 kg should receive the adult dose for chickenpox.

Adults and Children over 40 kg

800 mg 4 times daily for 5 days.

Intravenous ZOVIRAX is indicated for the treatment of varicella-zoster infections in immunocompromised patients.

When therapy is indicated, it should be initiated at the earliest sign or symptom of chickenpox. There is no information about the efficacy of therapy initiated more than 24 hours after onset of signs and symptoms.

Patients With Acute or Chronic Renal Impairment

In patients with renal impairment, the dose of ZOVIRAX Capsules, Tablets, or Oral Suspension should be modified as shown in Table 3.

Table 3. Dosage Modification for Renal Impairment

Normal Dosage Regimen



(mL/min/1.73 m2)

Adjusted Dosage Regimen



Dosing Interval

200 mg every 4 hours

> 10




every 4 hours, 5x daily

every 12 hours

400 mg every 12 hours

> 10




every 12 hours

every 12 hours

800 mg every 4 hours

> 25






every 4 hours, 5x daily

every 8 hours

every 12 hours


For patients who require hemodialysis, 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.

Bioequivalence of Dosage Forms

ZOVIRAX Oral Suspension was shown to be bioequivalent to ZOVIRAX Capsules (n = 20) and 1 ZOVIRAX 800-mg tablet was shown to be bioequivalent to 4 ZOVIRAX 200-mg capsules (n = 24).

Frequently asked questions

Further information

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