Why is this medication prescribed?
Acyclovir cream is used to treat cold sores (fever blisters; blisters that are caused by a virus called herpes simplex) on the face or lips. Acyclovir ointment is used to treat first outbreaks of genital herpes (a herpes virus infection that causes sores to form around the genitals and rectum from time to time) and to treat certain types of sores caused by the herpes simplex virus in people with weak immune systems. Acyclovir is in a class of antiviral medications called synthetic nucleoside analogues. It works by stopping the spread of the herpes virus in the body. Acyclovir does not cure cold sores or genital herpes, does not prevent outbreaks of these conditions, and does not stop the spread of these conditions to other people.
How should this medicine be used?
Topical acyclovir comes as a cream and an ointment to apply to the skin. Acyclovir cream is usually applied five times a day for 4 days. Acyclovir cream may be applied at any time during a cold sore outbreak, but it works best when it is applied at the very beginning of a cold sore outbreak, when there is tingling, redness, itching, or a bump but the cold sore has not yet formed. Acyclovir ointment is usually applied six times a day (usually 3 hours apart) for 7 days. It is best to begin using acyclovir ointment as soon as possible after you experience the first symptoms of infection. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Use topical acyclovir exactly as directed. Do not use more or less of it or use it more often than prescribed by your doctor.
Your symptoms should improve during your treatment with topical acyclovir. If your symptoms do not improve or if they get worse, call your doctor.
Acyclovir cream and ointment are for use only on the skin. Do not let acyclovir cream or ointment get into your eyes, or inside your mouth or nose, and do not swallow the medication.
Acyclovir cream should only be applied to skin where a cold sore has formed or seems likely to form. Do not apply acyclovir cream to any unaffected skin, or to genital herpes sores.
Do not apply other skin medications or other types of skin products such as cosmetics, sun screen, or lip balm to the cold sore area while using acyclovir cream unless your doctor tells you that you should.
To use acyclovir cream, follow these steps:
- Wash your hands.
- Clean and dry the area of skin where you will be applying the cream.
- Apply a layer of cream to cover the skin where the cold sore has formed or seems likely to form.
- Rub the cream into the skin until it disappears.
- Leave the skin where you applied the medication uncovered. Do not apply a bandage or dressing unless your doctor tells you that you should.
- Wash your hands with soap and water to remove any cream left on your hands.
- Be careful not to wash the cream off of your skin. Do not bathe, shower, or swim right after applying acyclovir cream.
- Avoid irritation of the cold sore area while using acyclovir cream.
To use acyclovir ointment, follow these steps:
- Put on a clean finger cot or rubber glove.
- Apply enough ointment to cover all of your sores.
- Take off the finger cot or rubber glove and throw it away in a trash can that is out of reach of children.
- Keep the affected area(s) clean and dry, and avoid wearing tight-fitting clothing over the affected area.
Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient. Read this information before you start using acyclovir and each time you refill your prescription.
Other uses for this medicine
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
What special precautions should I follow?
Before using topical acyclovir,
- tell your doctor and pharmacist if you are allergic to acyclovir, valacyclovir (Valtrex), any other medications, or any of the ingredients in acyclovir cream or ointment. Ask your pharmacist for a list of the ingredients.
- tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
- tell your doctor if you have or have ever had any condition that affects your immune system such as human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS).
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while using acyclovir, call your doctor.
What special dietary instructions should I follow?
Unless your doctor tells you otherwise, continue your normal diet.
What should I do if I forget a dose?
Apply the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not apply extra cream or ointment to make up for a missed dose.
What side effects can this medication cause?
Topical acyclovir may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- dry or cracked lips
- flaky, peeling, or dry skin
- burning or stinging skin
- redness, swelling, or irritation in the place where you applied the medication
Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately:
- difficulty breathing or swallowing
- swelling of the face, throat, lips, eyes, hands, feet, ankles, or lower legs
Topical acyclovir may cause other side effects. Call your doctor if you have any unusual problems while using this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].
What should I know about storage and disposal of this medication?
Keep this medication in the container it came in, with the cap on and tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Never leave this medication in your car in cold or hot weather. Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of emergency/overdose
If someone swallows topical acyclovir, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
What other information should I know?
Keep all appointments with your doctor.
Do not let anyone else use your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
- Zovirax® Cream
- Zovirax® Ointment
Brand names of combination products
- Xerese® (containing Acyclovir, Hydrocortisone)