Zovirax: General Information about the Drug

Zovirax, also known as acyclovir, is a medicine that fights viruses which cause herpes, commonly known as cold sores. Herpes can occur on mouth, nose, eyes and genitalia. It is also used to cure chicken pox and shingles.

How Does It Work?

The drug decreases the growth of viruses and stimulates the immune system to fight the “enemy” itself. It is not possible to get rid of herpes completely once it happened to be in the blood.

Zovirax only helps to decrease the symptoms. It is quite important to use Zovirax if you have genital herpes when giving birth as a baby might get the virus after his/her skin contacts mother’s skin.

How to Use It?

The sooner you start using Zovirax the better. The best is to take it when you start feeling itching, tingling or burning on your skin, or when blisters appear. The medicine should be used as prescribed by your doctor: until the last day, even if the symptoms have disappeared.

It is not recommended to take the drug longer than prescribed, or in smaller or higher doses. If you miss a dose, try to take it as soon as you remember, however, it is not advised to take a double dose at the next scheduled time. In rare cases overdose may make you feel half-conscious, agitated or even have seizures.

Zovirax is produced in oral or buccal tablets, oral capsules, intravenous powder for injections, compounding powder, in oral suspensions or as an intravenous solution. An oral suspension is to be shaken before usage, and a dose-measuring spoon has to be used.

The dose usually depends on weight and severity of the sores and should be administered by your healthcare provider.

Don’t forget that herpes is contagious. Avoid physical contacts (kissing or having sex in case of genital herpes) with other people while you have it. Avoid touching your eyes after touching the sores.

While taking Zovirax you are advised to:

  • Drink at least 1,5 l of water a day (to keep the kidneys work properly);
  • Keep the sore area dry and clean;
  • Wear loose clothes and underwear made of natural fabric in case of genital herpes;
  • Stay away from heat and humidity.

Possible Side Effects

It is common to experience headache, general ill-feeling, vomiting, nausea, stomach pain or diarrhea while taking Zovirax.

Sometimes it can cause pain in the lower back, red or purple pinpoint spots on the skin, little or no urinating, painful or difficult urination, tiredness, swelling of your ankles or feet, loss of appetite, easy bleeding and bruising. Inform your doctor about those symptoms at once.

The reason might be that the drug affected your kidneys.

Zovirax can be a reason of allergic reactions: swelling of your throat, tongue, lips or the whole face, difficulty breathing, hives. You must call the emergency at once if you have any of those.

Usage with Other Meds

Zovirax doesn’t interact with other drugs, food or vitamins, so it can be freely combined with other drugs.

However, it is better to consult a doctor if you’re using it in the same time with other antiviral drugs, probenecid, cimetidine, medicines to prevent organ transplant rejection, remedies for bowel disorders, injected antibiotics, injectable osteoporosis medications, pain meds or chemotherapy. It may increase a harmful effect on kidneys.


Don’t take Zovirax if you are allergic to acyclovir or valacyclovir. Consult your doctor in case you have other allergies because Zovirax may include inactive ingredients you may be allergic to.

It is advised to talk to a doctor if you’re breastfeeding, as it may be harmful for a baby. Inform your doctor about kidney diseases if any, pregnancy or plans to get pregnant if you are taking the drug.