MedlinePlus Drug Information: Acyclovir

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Other drug names:	A-Am An-Az B C-Ch Ci-Cz D-Dh Di-Dz E F G H I-J K-L M-Mh Mi-Mz N-Nh Ni-Nz O P-Pl Pm-Pz Q-R S-Sn So-Sz T-To Tp-Tz U-V W-Z 0-9

Acyclovir

(ay sye' kloe veer)

Brand name(s): Zovirax

Contents of this page:
Why is this medication prescribed? How should this medicine be used? What special precautions should I follow? What special dietary instructions should I follow? What should I do if I forget a dose?	What side effects can this medication cause? What storage conditions are needed for this medicine? In case of emergency/overdose What other information should I know?

Why is this medication prescribed?

Acyclovir is used to treat herpes infections of the skin, lip, and genitals; herpes zoster (shingles); and chickenpox. It does not cure herpes infections but decreases pain and itching and promotes healing.

Topical acyclovir does not prevent the recurrence of sores but may decrease pain and itching if applied when the earliest symptoms first appear. Oral acyclovir decreases the frequency and severity of recurrent sores, but it is used only by people with severe herpes infections because of possible adverse effects.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used?

Acyclovir comes as an ointment for use on the skin and as a tablet, capsule, and liquid to take by mouth. 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 than prescribed by your doctor. Use this medication as soon as possible after symptoms appear.

Clean and dry the skin area before applying the ointment. Wear protective gloves when applying it to prevent the spread of infection. Rub the ointment in gently. Use enough ointment to cover all sores completely. Do not apply acyclovir ointment to the eyes.

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

Continue to take acyclovir even if you feel well. Do not stop taking acyclovir without talking to your doctor.

What special precautions should I follow?

Before taking acyclovir,

tell your doctor and pharmacist if you are allergic to acyclovir, valacyclovir (Valtrex), or any other drugs.
tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially probenecid (Benemid), zidovudine (Retrovir, AZT), and vitamins.
tell your doctor if you have or have ever had kidney disease, problems with your immune system, human immunodeficiency virus infection (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 taking acyclovir, call your doctor.

What special dietary instructions should I follow?

Acyclovir may cause an upset stomach. Take acyclovir with food or milk.

What should I do if I forget a dose?

If you are using tablets, capsules, or liquid, take the missed dose as soon as you remember it and take any remaining doses for that day at evenly spaced intervals.

If you are using ointment, apply it as soon as you remember and apply further doses at your regular interval (e.g., every 3 hours) until you go to bed.

However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose of either the ointment or oral medication to make up for a missed one.

What side effects can this medication cause?

Although side effects from acyclovir are not common, they can occur. Tell your doctor if any of these symptoms are severe or do not go away:

burning, stinging, itching, or rash when ointment is applied
headache
upset stomach
vomiting
diarrhea or loose stools

If you experience any of the following symptoms, call your doctor immediately:

severe rash
severe itching
fever
confusion
yellowness of the skin or eyes
blood in the urine
stomach pain

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.

What other information should I know?

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

Do not have sexual intercourse when you can see the genital herpes lesions. However, genital herpes can be spread even when there are no symptoms.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription. If you still have symptoms of infection after you finish topical acyclovir, call your doctor.

Last Revised - 01/01/2003

American Society of Health-System Pharmacists, Inc. Disclaimer