Zovirax (Aciclovir)

What is Zovirax (aciclovir)?

Zovirax is a topical antiviral medicine used to treat cold sores in adults. It contains the antiviral ingredient aciclovir.

The brand Zovirax is owned by GlaxoSmithKline, though generic aciclovir cream is also available.

With Prescription Doctor's online prescription service, you can order Zovirax online from a UK regulated pharmacy.

To start your order, simply fill out the online questionnaire for one of our doctors to review.

If your order is approved before 3pm on a weekday, our pharmacy can dispatch your item the same day via a next-day, discreet delivery.

What are cold sores? 

Cold sores are caused by the herpes simplex virus (HSV-1). The virus can easily be transmitted through person to person contact. Cold sore symptoms appear as small fluid filled blisters on the lips or any other area around the face.

When the herpes virus infects the body, it targets the nerve cells and tissues around the face, which causes the outbreak of cold sores. Although the immune system attacks the virus initially, it does not completely rid the body of the virus.

Herpes can reside for as long as months or years in the nerve cells and body tissue. However, the virus can resurface and cause recurrent outbreaks when the body is subject to certain triggers like stress, menstruation or excessive exposure to sunlight.

Cold sores, caused by the herpes virus, can be highly contagious. There is currently no treatment to permanently remove the herpes virus from the body and prevent cold sore outbreaks, but there are antiviral medicines that can treat symptoms faster during an outbreak. 

Treatment should be started immediately to improve symptoms like itching and cold sore blisters, as the condition can be very painful and unsightly.

How does Zovirax (aciclovir) work for cold sores?

Zovirax cream contains the active ingredient aciclovir, which is an antiviral agent. Aciclovir works against the herpes virus by stopping it from multiplying in the nerve cells and tissues of the body. 

When aciclovir enters the herpes virus, it becomes another compound called aciclovir triphosphate. This compound acts to inhibit an enzyme which is necessary for the virus to multiply and spread, enabling the immune system to attack the virus into remission.

Zovirax cream helps to improve the symptoms of cold sores and speed up recovery, but it does not prevent the virus from being passed on to another person.

How long does it take for Zovirax (aciclovir) to work?

Zovirax should clear up your cold sore within 4 days. If you have a cold sore after 4 days of using Zovirax, speak to your doctor.

How do I use Zovirax?

Zovirax cream should only be applied generously on the skin, specifically on cold sore lesions.

You should ensure that you wash your hands before and after applying the cream.

Zovirax cream should be used as soon as cold sore symptoms such as tingling and itching present, however, it can also be used later on when blisters appear.

Zovirax cream should be applied 5 times a day for 4 full days to ensure speedy healing.

If there are no improvements with symptoms after 4 days, users can continue applying the cream for up to 10 days.

If your cold sore worsens, or does not fully heal after 10 of using Zovirax cream for 10 consecutive days, stop using the cream and consult your doctor for further advice.

What should I do if I accidentally use more Zovirax cream than I should?

If you accidentally use more Zovirax cream than you should, speak to your doctor for advice.

What should I do if I or someone else swallows Zovirax cream?

Zovirax cream is for external use only. If you or someone else swallows Zovirax cream by accident, seek immediate medical attention by going directly to your nearest accident and emergency department. Remember to take the packaging and any of the remaining medicine so that the doctors treating you know exactly what you have taken.

What should I do if I forget to use Zovirax cream when I should?

If you miss your dose of Zovirax cream, apply the dose as soon as you remember. If there is almost time for your next dose, skip the missed dose and continue to use Zovirax cream as you normally would. Do not apply more Zovirax cream to make up for the missed dose.

Side effects and cautions

All medicines carry the risk of side effects, though not everybody experiences them. For the full list of Zovirax cream side effects, cautions and drug interactions, read the patient information leaflet supplied with your medicine.

You can view the patient information leaflet (PIL) for Zovirax Cream online (PDF)

Uncommon side effects include:

• Irritation, such as burning, itching or stinging at the sight of the application.
• Mild drying or flaking of the skin

This is not an exhaustive list of side effects. Further information regarding the safety of Zovirax cream can be found within the patient information leaflet enclosed with your medicine.

Allergies

Do not use Zovirax if you are allergic to aciclovir or any other ingredients of this medicine. You can find the full list of Zovirax ingredients in the patient information leaflet supplied with your medicine.

Pregnancy and breastfeeding

Tell your doctor or pharmacist before using Zovirax (aciclovir) cream if you are pregnant, planning to be pregnant, or are breastfeeding.

Other safety information

Before you use Zovirax cream, it's important to familiarise yourself with the warnings presented in the patient information leaflet enclosed with your medicine.

Please inform our prescriber of all the medicines you are currently taking, including those prescribed, or bought over the counter, as well as herbal treatments.

Do not use Zovirax (aciclovir) cream past the expiry date printed on the label. The date refers to the last day of the specified month.

Never throw away medicines via household or water waste, as this can damage the environment. Instead, you should take all unwanted or expired medicines to your local pharmacy and ask them to dispose them safely on your behalf.

Always store Zovirax cream out of the sight and reach of children and pets.

Never share medicines prescribed to you with anybody else - even if they are experiencing the same symptoms or have been diagnosed with the same condition as you.