Guidelines before using Zovirax cream for cold sores

Zovirax cream (acyclovir or aciclovir) is a prescription antiviral medication used to treat cold sores in adults and adolescents age 12 and older. Cold sores are caused by viruses - specifically, the herpes simplex viruses (HSV). Zovirax cream is an antiviral medication that helps the body fight the infection by preventing the virus from multiplying.

It is important to understand that once a person has been infected with these viruses, they never go away. They remain inactive in certain nerve cells of the body, waiting to become active again. In addition, treatment with Zovirax cream does not prevent future outbreaks of cold sores.

Before using Zovirax Cream:

Some medical conditions may interact with Zovirax Cream. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

* if you are pregnant, planning to become pregnant, or are breast-feeding
* if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
* if you have allergies to medicines, foods, or other substances

Ask your health care provider if Zovirax cream may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine. Do not use this medicine if you are allergic to acyclovir or valacyclovir (Valtrex). Before using acyclovir, tell your doctor if you are allergic to any drugs, or if you have:

* kidney disease (or if you are on dialysis);
* liver disease;
* a brain or nervous system disorder such as Parkinson's disease, schizophrenia, or tardive dyskinesia;
* breathing problems; or
* an electrolyte imbalance (such as high or low calcium , sodium, or potassium blood levels).

If you have any of these conditions, you may need a dose adjustment or special tests to safely use acyclovir injection.

This medicine is not known to be harmful if used during pregnancy. It is absorbed into the bloodstream only in very low amounts after being applied to the lips. However, the manufacturer states that it should be used with caution during pregnancy, and only if the expected benefit to the mother is greater than any possible risk to the baby. If you are pregnant you should ask your doctor for advice before using this medicine.