Drug Name

Zovirax (Acyclovir)

 Drug Uses

Zovirax 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 Zovirax does not prevent the recurrence of sores but may decrease pain and itching if applied when the earliest symptoms first appear. Oral Zovirax 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 Taken

Treatment with Zovirax topical should be started as soon as possible after the first appearance of symptoms (e.g. tingling, burning, blisters). Wash your hands before and after applying Zovirax topical. Wear a glove or a finger cot or use an applicator (e.g. cotton swab) when applying Zovirax topical to avoid spreading the virus to other body parts and to other people. Apply enough ointment to cover the lesion(s) completely. A one-half inch ribbon of ointment should cover approximately 4 square inches of surface area. Avoid getting this medication in the eyes. Zovirax topical is usually applied every 3 hours, six times a day for seven days. Follow your doctor's instructions. Use Zovirax topical for the full amount of time prescribed, even if you begin to feel better. Your symptoms may start to improve before the infection is completely treated. Lesions caused by herpes viruses should be kept as clean and dry as possible. Wearing loose clothing may help to prevent irritation of the lesions.

 Drug Class and Mechanism

Viral illnesses differ from bacterial infections in that viruses are not living organisms, but rather take over living cells and reproduce themselves, often at the expense of the host cell. Acyclovir is an antiviral drug which acts against the Herpes viruses, including herpes simplex 1 and 2 (cold sores and genital herpes), varicella-zoster (shingles and chicken pox), and the Epstein-Barr virus (mononucleosis). Acyclovir inhibits the replication of viral DNA needed to reproduce itself. Virally infected cells absorb more acyclovir than normal cells and convert more of it to an active form which prolongs its antiviral activity where it is most needed.

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 to make up for a missed one.

Store below 25 degrees C. Do not refrigerate.

 Warnings/Precautions

Before using Zovirax topical, tell your doctor if you have any other medical conditions or if you use any other medications. Zovirax topical is in the FDA pregnancy category C, which means that it is not known whether it will harm an unborn baby. Do not use Zovirax topical without first talking to your doctor if you are pregnant. It is not known whether Zovirax topical passes into breast milk. Do not use Zovirax topical without first talking to your doctor if you are breast feeding a baby.

 Possible Side Effects

No serious side effects are expected during treatment with Zovirax topical. If you suspect an allergic reaction (difficulty breathing; rash; hives; itching; swelling of your lips, tongue, or face) seek emergency medical attention. Other less serious side effects may be more likely to occur. Continue to use Zovirax topical and talk to your doctor if you experience itching, stinging, burning, or a rash. These side effects should resolve quickly. Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

 More Information

• Stop taking acyclovir and seek emergency medical attention or contact your doctor immediately if you experience any of the following serious side effects:
  • an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives);
  • little or no urine production; or
  • unusual bleeding or bruising.
• Other, less serious side effects may be more likely to occur. Continue to take acyclovir and talk to your doctor if you experience
• nausea, vomiting, diarrhea, decreased appetite, or abdominal pain;
• a headache or lightheadedness; or
• joint pain.
• Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.