What is Zovirax used for?

• Genital herpes
• Shingles (Herpes zoster)
• Chickenpox (Varicella)
• Cold sores (Herpes labialis)

Herpes viruses are a family of viruses, including varicella-zoster virus (VCZ) and herpes simplex virus (HSV).

Chickenpox and shingles are skin conditions caused by the varicella-zoster virus. These are also known as herpes zoster infections. Symptoms of chickenpox and shingles are painful rash which is treatable with Zovirax.

Genital herpes and cold sores are sexually-transmitted infections caused by the herpes simplex virus (HSV). Symptoms can appear days or weeks after exposure. 

There may be other uses of Zovirax—your pharmacist or physician can give you further information and assistance.

How does Zovirax work?

Zovirax belongs to a class of antiviral medications called synthetic nucleoside analogues. Zovirax reduces the ability of the herpes viruses to multiply in the body. Zovirax works by inhibiting the herpes virus DNA polymerase. Without this enzyme (DNA polymerase), herpes viruses can’t make copies of themselves. Zovirax (acyclovir) is eliminated via active renal tubular secretion. Meaning, Zovirax is cleared mainly through the kidney. For patients with impaired renal function, Zovirax or acyclovir doses will need to be adjusted based on their renal function. 

Zovirax does not cure herpes, but by preventing the virus from multiplying, Zovirax reduces the severity and duration of the infection.

What is the suggested dosing for Zovirax? 

For patients with renal impairment or reduced renal function, Zovirax dosage must be adjusted accordingly to their renal functions. 

Typical dosing of Zovirax for shingles:

• Take 800 mg (oral tablet or capsule) by mouth five times daily for 7 to 10 days 

Typical dosing of Zovirax for genital herpes:

• For treatment: Take 200 mg (oral tablet or capsule) five times daily for 10 days. May extend treatment if not healed after 10 days. 
• Suppressive therapy (taken daily to prevent recurrent herpes simplex infections): take 400 mg (oral tablet or capsule) by mouth twice daily for up to 12 months. Reassess treatment need at 1 year. 
• Topical: Apply the ointment or cream 6 times daily (every 3 hours) for 7 days. Start at symptoms onset. Use enough cream or ointment to cover all the lesions. Wearing gloves is recommended to prevent the spreading of the virus. 

Typical dosing of Zovirax for chickenpox:

• Adults: 
  • Take 800 mg (oral tablet or capsule) by mouth four times daily for 5 days 
• Children between 2 and 18 years old: the dose is weight-based 
  • For oral administration, the dose is typically 80mg/kg/day divided into 4 doses (every 6 hours)
  • The duration of treatment is 5 days
  • The maximum daily dose is 3200 mg
  • Therapy is to be started as soon as possible within 24 hours of rash onset.

Typical dosing of Zovirax for cold sores:

• Place 1 buccal tablet (50 mg) in the mouth between the upper cheek and gum