Consumer medicine information

ZOVIRAX® 400 mg Tablets

Aciclovir 400 mg

Consumer Medicine Information

What is in this leaflet

This leaflet answers some common questions about Zovirax® 400 mg tablets (Zovirax 400). It does not contain all of the available information.

Reading this leaflet does not take the place of talking to your doctor or pharmacist.

Taking any medicine involves some risk. It is possible that all risks associated with this medicine might not have been detected, despite proper testing. Only your doctor or pharmacist is able to weigh up all of the relevant facts, and you should consult them if you have any queries.

If you have any concerns about taking Zovirax 400 ask your doctor or pharmacist.

Keep this information.

You may want to read it again. This leaflet provides information about Zovirax 400. The statements that are made in this leaflet cannot be applied to any other medicine, even those that are similar or appear to contain the same ingredients.

What Zovirax 400 is used for

Zovirax 400 is used for the treatment of shingles (herpes zoster).

How does Zovirax 400 work

Aciclovir (the active ingredient in Zovirax 400) belongs to a group of medicines called “anti-virals”. Zovirax 400 works by stopping the production of the herpes virus. This reduces the length and severity of an outbreak of herpes. Zovirax 400 does not get rid of the virus from your body.

Your doctor may, however, have prescribed Zovirax 400 for a different use to that described above.

If you have any questions about why you are taking Zovirax 400 ask your doctor or pharmacist. Your doctor or pharmacist will be able to provide you with more information.

Before you take Zovirax 400

Zovirax 400 is not suitable for everyone.

Be sure that your doctor knows about the following before you take Zovirax 400:

  1. If you are allergic to:
    – Aciclovir (the active ingredient in Zovirax 400) or valaciclovir.
    – Any other ingredient listed at the end of this leaflet.
  2. If you are pregnant, or become pregnant while using Zovirax 400, or are breastfeeding.
  3. If you suffer from:
    – A kidney or liver condition, or
    – A blood condition, or
    – Any condition affecting your brain.

Taking other medicines

Tell your doctor or pharmacist if you are taking any other medications, including any that you get without a prescription from your pharmacy, supermarket or health food shop.

Some medicines and ZOVIRAX 400 may interfere with each other. These include:

  • medicines used to prevent gout or gouty arthritis such as probenecid.
  • fluid tablets (diuretics).
  • medicines used to treat gastric ulcers or reflux such as cimetidine.
  • medicines used prevent rejection of transplanted organs such as mycophenolate mofetil.

These medicines may be affected by ZOVIRAX or may affect how well it works. You may need different amounts of your medicines, or you may need to take different medicines.

Your doctor and pharmacist have more information on medicines to be careful with or avoid while taking this medicine.

When you must not take Zovirax 400

Do not take Zovirax 400 after the expiry date printed on the pack.

Do not take Zovirax 400 if the packaging shows signs of tampering.

Do not take Zovirax 400 to treat any other conditions unless advised by your doctor.

Do not give Zovirax 400 to anyone else, even if their symptoms seem similar to yours.

Taking Zovirax 400

Take Zovirax 400 as directed by your doctor or pharmacist. Never change the dose yourself.

Your doctor and pharmacist will be able to tell you:

  • how many tablets to take at each dose.
  • how many doses to take each day.
  • when to take each of your doses.

The label on the pack that the tablets were supplied in will give the same information. If there is something that you do not understand ask either your doctor or pharmacist.

The usual dose of Zovirax 400 is two 400 mg tablets every four hours while awake (a total of ten tablets daily) for 7 days.

The shingles compliance pack will help you remember to take the tablets at the correct times.

Your doctor may also vary the Zovirax 400 dosage for other medical reasons.

If you have any questions about the dose that you have been prescribed you should ask your doctor or pharmacist.

How to take Zovirax 400

Your Zovirax 400 tablets may be swallowed whole with a glass of water, or dispersed in a quarter of a glass of water (about 50 mL) and then swallowed.

If you forget to take your dose

If you have just missed your scheduled dose, take it as soon as you remember and continue as before.

If you have forgotten to take one dose of Zovirax 400 and it is almost time to take your next scheduled dose, then skip the dose you have missed, and continue taking your Zovirax 400 as directed by your doctor or pharmacist.

If you have forgotten to take more than one dose contact your doctor or pharmacist for advice.

Do not take a double dose to make up for the dose that you have missed.

If you have trouble remembering when to take your medicine, as your pharmacist for some hints.

In case of overdose

Immediately contact your doctor or Poisons Information Centre (telephone 13 11 26) for advice, or go to accident and emergency at your nearest hospital, if you think that you may have taken too much, or if anyone else may have taken too much Zovirax 400. Do this even if there are no signs of discomfort or poisoning. You may need urgent medical attention.

Keep telephone numbers for these places handy.

While you are taking Zovirax 400

Drink plenty of plain fluids. Your doctor or pharmacist will be able to tell you whether there are any special instructions while you are taking Zovirax 400.

See your doctor if you feel that your condition is not improving or getting worse.

Driving and using machines

Some side effects such as feeling drowsy or sleepy may impair your ability to concentrate and react. Make sure you are not affected before you drive or operate machinery

When to stop taking Zovirax 400

Do not stop taking Zovirax 400 just because you feel better. It is important that you complete your course of tablets to effectively treat the shingles.

Your doctor will advise you when to stop taking Zovirax 400. If you are unsure whether you should stop taking Zovirax 400 talk to your doctor or pharmacist.

Side Effects

All medicines can have some side effects. Sometimes they are serious. Most of the time they are not.

Zovirax 400 helps most people with shingles. In a few people it may have some unwanted side effects.

Be sure that your doctor or pharmacist knows as soon as possible if you do not feel well while you are taking Zovirax 400. Often it is difficult to tell the difference between side effects of medication and symptoms of the underlying illness.

Tell your doctor if you notice any of the following:

  • Severe allergic reactions (rare). Signs include: itchy, bumpy rash (hives), swelling sometimes of mouth causing difficulties breathing, collapse. Contact your doctor immediately if you get these symptoms. Stop taking Zovirax.
  • Nausea, vomiting, diarrhoea, stomach pain, headache, dizziness, confusion, hallucinations, seizures, fatigue, itching, skin reaction after sunlight exposure, and fever.

Less common side effects include:

  • Hair loss, itchy, bumpy rash (urticaria).
  • Chest pain, shortness of breath, aching.
  • Constipation.
  • Taste disturbance.
  • Liver disorders.
  • Vertigo, difficulty sleeping.

A small number of patients have had other unwanted effects after taking Zovirax 400.

There is no evidence that Zovirax 400 is addictive.

Ask your doctor or pharmacist to answer any questions you may have.

Ask your doctor or pharmacist if you don’t understand anything in this list.

Do not be alarmed by this list of possible side-effects. You may not experience any of them.

After taking Zovirax 400

If your doctor advises you to stop taking Zovirax 400 ask your pharmacist what to do with any remaining tablets.


Keep your tablets in the pack that they were supplied in.

Keep Zovirax 400 in a cool, dark and dry place where the temperature stays below 30°C. Do not store Zovirax 400 in the bathroom or near a sink. Heat and dampness may affect Zovirax 400.

Keep Zovirax 400, and all other medicines, where children cannot reach them.

Do not leave Zovirax 400 in the car on hot days.

Product description

What Zovirax 400 looks like

Zovirax 400 tablets are white, concave, shield-shaped, film-coated tablets, branded GXCF5 on one side and plain on the other. They are available in packs of 100 tablets.

The information provided applies only to: Zovirax 400 mg tablets.


Zovirax 400 contains 400 mg of the active ingredient aciclovir.

Zovirax 400 also contains:

  • cellulose-microcrystalline
  • povidone
  • sodium starch glycollate
  • aluminium magnesium silicate
  • magnesium stearate
  • macrogol 8000
  • coating opadry Y-1-7000 concentrate


Zovirax 400 tablets are supplied in Australia by:
GlaxoSmithKline Australia Pty Ltd
Level 4, 436 Johnston Street
Abbotsford, Victoria, 3067

AUST R 51428

This leaflet was prepared on 13 February 2015.

Zovirax® is a registered trade mark of the GlaxoSmithKline group of companies.

© 2013 GlaxoSmithKline.

Version 5.0

Published by MIMS July 2015