Health Centres - Zovirax cold sore cream
How does it work?
Zovirax cold sore cream contains the active ingredient aciclovir, which is an antiviral medicine used to treat infections with the herpes virus. This cream is used to treat cold sores, which are caused by infection with the herpes simplex virus.
Aciclovir works by stopping the herpes simplex virus from reproducing and infecting more cells.
Aciclovir is converted to a more active form inside cells of the body that are infected with herpes simplex. The activated aciclovir then works by blocking the action of a viral enzyme called DNA polymerase.
The herpes virus needs the DNA polymerase enzyme to copy its genetic material from RNA to DNA. This process is necessary for the virus to multiply and continue to survive. By blocking the action of DNA polymerase, aciclovir prevents the herpes virus from multiplying. This controls the infection and helps the immune system to deal with it.
This aciclovir cream is designed for the treatment of herpes simplex infections of the lips (cold sores) and is not recommended for use in genital herpes.
For recurrent cold sores aciclovir cream is most effective if treatment is started as soon as the first signs of the infection begin to reappear.
What is it used for?
Warning!
- Avoid contact with eyes
- This preparation is for external use only.
- This cream is not suitable for application to mucous membranes such as inside the mouth, eye or vagina, as it may be irritant to these areas.
- Wash your hands before and after applying the cream and avoid touching sores unnecessarily, with either hands or towels, to avoid spreading the infection.
- This medicine is not recommended for the treatment of infections in people whose immune systems have a decreased ability to fight infections (immunocompromised people, for example people with AIDS or people who have had a bone marrow transplant). These people should consult their doctor concerning the treatment of infections so that the most effective treatment can be prescribed.
Not to be used in
-
Genital herpes
- Herpes simplex virus infection of the eye
This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.
Pregnancy and Breastfeeding
Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby.

