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Overview: Topical acyclovir is used to treat certain symptoms of cold sores or genital herpes. It is an antiviral medicine. Common side effects include burning, stinging, itching, or dryness where it is applied. Topical acyclovir is available in a cream and ointment.

Uses

What is topical acyclovir used for?

Topical acyclovir is applied to the skin and is commonly used to treat certain symptoms associated with cold sores and genital herpes.

Topical acyclovir may also be used for other conditions as determined by your healthcare provider.

How does topical acyclovir work (mechanism of action)?

Topical acyclovir is an antiviral medicine that stops the growth of herpes viruses and improves symptoms. It is important to note that topical acyclovir is not a cure. The herpes viruses remain in the body even if you do not have symptoms.

How is topical acyclovir supplied (dosage forms)?

Brands and other names

  • Zovirax

Dosage forms and strengths

  • 5% topical cream
  • 5% topical ointment

Acyclovir is also available for use by mouth or injection. See Acyclovir for more information.

Acyclovir is also available as a buccal tablet that dissolves in the mouth. See Sitavig for more information.

How should I store topical acyclovir?

Topical acyclovir should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place.

Side Effects

What are the most common side effects of topical acyclovir?

The most common side effects of topical acyclovir are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Mild pain
  • Dry, flaky skin
  • Itchiness
  • Burning or stinging sensation

There may be other side effects of topical acyclovir that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of topical acyclovir?

While less common, the most serious side effects of topical acyclovir are described below, along with what to do if they happen.

Severe Allergic Reactions. Topical acyclovir may cause allergic reactions, which can be serious. Stop using topical acyclovir and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Warnings & Precautions

Who should not use topical acyclovir?

Allergies to Ingredients. People who are allergic to any of the following should not use topical acyclovir.

  • Acyclovir
  • Valacyclovir
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific topical acyclovir products they stock.

What should I know about topical acyclovir before using it?

Do not use topical acyclovir unless it has been prescribed to you by a healthcare provider. Use it as prescribed. Ask your healthcare provider if you are not sure where or how to apply topical acyclovir.

Do not share topical acyclovir with other people, even if they have the same condition as you. It may harm them.

Keep topical acyclovir out of the reach of children.

Use topical acyclovir as soon as possible when you first have symptoms.

Topical acyclovir is for external use only. It should not be used in the eye.

Avoid touching the affected area, as this may spread the infection. 

Wash your hands with soap and water before and after applying topical acyclovir. Make sure the area where you are applying topical acyclovir is clean and dry. To prevent spreading the infection to other parts of the body, wear a protective glove when applying topical acyclovir. 

Do not apply other topical products to the same area where you are using topical acyclovir unless your healthcare provider tells you otherwise.

What should I tell my healthcare provider before using topical acyclovir?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if topical acyclovir is right for you.

In particular, make sure that you discuss any of the following.

Weak Immune System. Tell your healthcare provider if you have a weak immune system before using topical acyclovir.

Pregnancy. It is not known if or how topical acyclovir could affect pregnancy or harm an unborn baby. Tell your healthcare provider if you are or plan to become pregnant. Your healthcare provider will advise you if you should use topical acyclovir while you are pregnant or trying to get pregnant. 

Breastfeeding. It is not known if topical acyclovir passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should use topical acyclovir while breastfeeding.

Interactions

Does topical acyclovir interact with foods or drinks?

There are no known interactions between topical acyclovir and foods or drinks.

It is unknown if drinking alcohol will affect topical acyclovir, but heavy drinking can slow your immune response and make it harder for your body to fight infection.

Does topical acyclovir interact with other medicines (drug interactions)?

There are no known interactions between topical acyclovir and other medicines. Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much topical acyclovir?

If you or someone else has used too much topical acyclovir, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of topical acyclovir?

If you miss a dose, use it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only use the next dose. Do not use double or extra doses.