Why is this medication prescribed?  

Acyclovir is used to decrease pain and speed the healing of sores or blisters in people who have varicella (chickenpox), herpes zoster (shingles; a rash that can occur in people who have had chickenpox in the past), and first-time or repeat outbreaks of genital herpes (a herpes virus infection that causes sores to form around the genitals and rectum from time to time). Acyclovir is also sometimes used to prevent outbreaks of genital herpes in people who are infected with the virus. 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 will not cure genital herpes and may not stop the spread of genital herpes to other people.

How should this medicine be used?  

Acyclovir comes as a tablet, a capsule, and a suspension (liquid) to take by mouth. It is usually taken with or without food two to five times a day for 5 to 10 days, starting as soon as possible after your symptoms begin. When acyclovir is used to prevent outbreaks of genital herpes, it is usually taken two to five times a day for up to 12 months. Take acyclovir at around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take acyclovir exactly as directed. Do not take more or less of it or take it more often or for a longer time than prescribed by your doctor.

Shake the liquid well before each use to mix the medication evenly.

Your symptoms should improve during your treatment with acyclovir. Call your doctor if your symptoms do not improve or if they get worse.

Take acyclovir until you finish the prescription, even if you feel better. If you stop taking acyclovir too soon or skip doses, your infection may not be completely treated or may become more difficult to treat.

Other uses for this medicine  

Acyclovir is also sometimes used to treat eczema herpeticum (a skin infection caused by the herpes virus) to treat and prevent herpes infections of the skin, eyes, nose, and mouth in patients with human immunodeficiency virus (HIV), and to treat oral hairy leukoplakia (condition that causes hairy white or gray-colored patches on the tongue or inside of the cheek).

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What storage conditions are needed for this medicine?  

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). 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  

In case of overdose, 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.

Symptoms of overdose may include:

• agitation
• seizures
• extreme tiredness
• loss of consciousness
• swelling of the hands, feet, ankles, or lower legs
• decreased urination

What other information should I know?  

Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your response to acyclovir.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

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Other names