Aciclovir Cream

Medication Information Leaflet

What is this medication for?

Aciclovir cream is used for the treatment of mild herpes simplex infections of the lips (cold sores) and the skin.

Aciclovir works by stopping the growth of the Herpes simplex virus (HSV) that causes cold sores. While aciclovir cream does not prevent cold sores from coming back, it can reduce the severity and duration of the cold sore symptoms when they appear.

Symptoms of cold sores often include itching, burning or tingling before blisters appear. The blisters may merge and burst before crusting over. The HSV is able to infect other parts of the body or can spread to others, via direct contact with the cold sores or contaminated items (e.g. towels, eating and drinking utensils). The HSV can also be sexually transmitted.

How should I use this medication?

  • Wash and dry hands before and after use to prevent the spread of infection

  • Apply aciclovir cream on the blisters. It is best to apply when the first signs of a cold sore appear (e.g. itching, tingling)

  • Apply a thin layer to the affected areas 5 times a day, approximately every 4 hours. You do not need to apply the cream when you are asleep

  • Continue application for at least 5 days, or up to 10 days if the cold sores have not healed

  • For cold sores on the lips, apply aciclovir cream after eating or drinking to minimize accidental swallowing of the medication

What should I do if I forget to use this medication?

If you forget to apply a dose, apply as soon as you remember. If it is nearly time for the next application, skip the missed application and continue with the next dose at the usual time.

What precautions should I take?

Inform your healthcare professional if:

  • You are allergic to this medication & other similar antivirals (e.g. valacyclovir), or any of the other ingredients of this medication (e.g. propylene glycol)

  • You have a weakened immune system due to an illness such as AIDS (Acquired Immuno-Deficiency Syndrome) or you have had a bone marrow transplant

Take care to avoid accidental application into the eye or inside the mouth.

What are some common side-effects of this medication?

  • Itching

  • Temporary burning or stinging sensation after application

  • Mild drying or flaking of skin

Consult your healthcare professional if the symptoms do not go away or become bothersome.

What are some rare but serious side-effects that I need to seek medical advice immediately?

The symptoms of a drug allergy include one or more of the following:

  • Swollen face/eyes/lips/tongue

  • Difficulty in breathing

  • Itchy skin rashes over your whole body

If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children.

How should I throw away this medication safely?

Pack this medication into a black trash bag and seal it tightly before throwing it into the rubbish chute or bin.


Please take note that the above is not a complete list of all possible side effects. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on Oct 2022

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