Chickenpox (Varicella Zoster) Antiviral Prescribing

Comments from Expert Advisory Group

Seek secondary care advice in patients who are:

  • Pregnant
  • Immunocompromised
  • Neonates
  • Displaying systemic symptoms of chickenpox

Look for signs of complications such as secondary bacterial infection of skin lesions, pneumonia, and encephalitis.

HPSC update on group A Streptococcus

Non-immune women significantly exposed to varicella at any stage of pregnancy should be offered post exposure prophylaxis (PEP). See NIAC guidance on varicella zoster for more information.

Varicella Zoster on the chest

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Close up of Varicella Zoster vesicle

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Prescribing Considerations

  • In immunocompetent patients the value of antivirals is minimal
  • Consider prescribing oral aciclovir within 24 hours of onset of rash in patients with one or more of the following:
    • ≥14 years of age
    • severe rash
    • severe pain
    • smoker
    • secondary household cases
    • immunocompromised (start oral aciclovir while seeking secondary care advice about need for IV aciclovir)

Chickenpox Treatment

Chickenpox (Varicella Zoster) Antiviral Treatment
 Drug Dose Duration Notes
Adults (if indicated)

800mg Five Times Daily

Doses to be taken five times a day at approximately 4 hourly intervals, during waking hours.

 7 Days For dose reduction in renal impairment
 Children (if indicated)

Child 1-23 Months:
200mg Four Times Daily

Child 2-5 years:
400mg Four Times Daily

Child 6-11 years:
800mg Four Times Daily

Child 12 and over:
As per adult dose

5 Days

5 Days

5 Days

7 Days


Dispersible Tablets and Liquid Available

For dose reduction in renal impairment

General Advice for Self-Care with Chickenpox

  • Patients should be advised they are contagious until all the vesicles have scabbed over (usually 5-7 days after onset of rash)
  • Pregnant women, who have not had chickenpox, should avoid patients with chickenpox/shingles
  • Use simple emollients, antihistamines & antipyretics for symptom relief – seek advice from pharmacist
  • Avoid NSAIDs due to increased risk of severe skin and soft-tissue infection
  • Advise to keep nails short and clean to minimise scratching and secondary bacterial infection. Socks over hands at night may help prevent scratching.
  • Bathe in lukewarm, not hot water.
  • Keep hydrated – ice lollies may be helpful if mouth is sore.

Patient Information

Safe Prescribing (visit the safe prescribing page)

Reviewed November 2022

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