Acyclovir dosage and administration
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Dosage And Administration
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 Suspension should be modified as shown in Table 3.
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Hemodialysis
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 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).[1]
References
- ↑ "http://www.accessdata.fda.gov/drugsatfda_docs/label/2004/18603slr027_zovirax_lbl.pdf" (PDF). External link in
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Adapted from the FDA Package Insert.