ZOVIRAX (acyclovir)

ZOVIRAX

Patient Education - English

• Generic Name: acyclovir (oral)

• Pronounced: a SYE klo veer

• Brand Name: Zovirax

What is the most important information I should know about acyclovir?

Take this medication for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated.

Treatment with acyclovir should be started as soon as possible after the first appearance of symptoms (such as tingling, burning, blisters).

Herpes infections are contagious and you can infect other people, even while you are being treated with acyclovir. Avoid letting infected areas come into contact with other people. Avoid touching an infected area and then touching your eyes. Wash your hands frequently to prevent passing the infection to others.

What is acyclovir?

Acyclovir is an antiviral drug. It slows the growth and spread of the herpes virus so that the body can fight off the infection. Acyclovir will not cure herpes, but it can lessen the symptoms of the infection.

Acyclovir is used to treat infections caused by herpes viruses. Illnesses caused by herpes viruses include genital herpes, cold sores, shingles, and chicken pox.

Acyclovir may also be used for purposes other than those listed in this medication guide.

What should I discuss with my healthcare provider before taking acyclovir?

Do not take this medicine if you are allergic to acyclovir or valacyclovir (Valtrex).

Before taking acyclovir, tell your doctor if you are allergic to any drugs, or if you have kidney disease. You may need a dosage adjustment or special tests during treatment.

FDA pregnancy category B. This medication is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. Herpes virus can be passed from an infected mother to her baby during childbirth. If you have genital herpes, it is very important to prevent herpes lesions during your pregnancy so that you do not have a genital lesion when your baby is born.

Acyclovir passes into breast milk and may harm a nursing infant. Do not take this medication without telling your doctor if you are breast-feeding a baby.

How should I take acyclovir?

Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.

Treatment with acyclovir should be started as soon as possible after the first appearance of symptoms (such as tingling, burning, blisters).

Take each dose with a full glass of water. Drink plenty of water while you are taking acyclovir to keep your kidneys working properly.

Acyclovir can be taken with or without food. Taking acyclovir with food may decrease stomach upset.

Shake the oral suspension (liquid) well just before you measure a dose. To be sure you get the correct dose, measure the liquid with a marked measuring spoon or medicine cup, not with a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.

Take this medication for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated. Acyclovir will not treat a viral infection such as the common cold or flu.

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.

Store acyclovir at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include seizure (convulsions), hallucinations, and urinating less than usual or not at all.

What should I avoid while taking acyclovir?

Herpes infections are contagious and you can infect other people, even while you are being treated with acyclovir. Avoid letting infected areas come into contact with other people. Avoid touching an infected area and then touching your eyes. Wash your hands frequently to prevent passing the infection to others.

Acyclovir will not prevent the spread of genital herpes. Avoid sexual intercourse or use a latex condom to prevent spreading the virus to others.

What are the possible side effects of acyclovir?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these serious side effects:

• pain in your lower back;
• urinating less than usual or not at all;
• easy bruising or bleeding; or
• unusual weakness.

Less serious side effects may include:

• nausea, vomiting, diarrhea, loss of appetite, stomach pain;
• headache, feeling light-headed; or
• swelling in your hands or feet.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect acyclovir?

Before taking acyclovir, tell your doctor if you are also taking probenecid (Benemid). If you are using probenecid, you may not be able to use acyclovir, or you may need dosage adjustments or special tests during treatment.

There may be other drugs that can affect acyclovir. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Where can I get more information?

Your pharmacist can provide more information about acyclovir.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Zovirax liquid, capsules, and tablets are used in the treatment of certain infections with herpes viruses. These include genital herpes, shingles, and chickenpox. This drug may not be appropriate for everyone, and its use should be thoroughly discussed with your doctor. Zovirax ointment is used to treat initial episodes of genital herpes and certain herpes simplex infections of the skin and mucous membranes. Zovirax cream is used for herpes cold sores on the lips and face only.

Zovirax liquid, capsules, and tablets are used in the treatment of certain infections with herpes viruses. These include genital herpes, shingles, and chickenpox. This drug may not be appropriate for everyone, and its use should be thoroughly discussed with your doctor. Zovirax ointment is used to treat initial episodes of genital herpes and certain herpes simplex infections of the skin and mucous membranes. Zovirax cream is used for herpes cold sores on the lips and face only.

Some doctors use Zovirax, along with other drugs, in the treatment of AIDS, and for unusual herpes infections such as those following kidney and bone marrow transplants.

Most important fact about Zovirax

Zovirax does not cure herpes. However, it does reduce pain and may help the sores caused by herpes to heal faster. Genital herpes is a sexually transmitted disease. To reduce the chance of infecting your partner, forgo intercourse and other sexual contact while you have sores or any other symptom.

How should you take Zovirax?

Your medication should not be shared with others, and the prescribed dose should not be exceeded. You can take Zovirax with or without food.

Zovirax ointment should not be used in or near the eyes. To reduce the risk of spreading the infection, use a rubber glove to apply the ointment.

Zovirax cream should not be used in or near the eyes, or inside the nose or mouth. The medication can, however, be applied on the outside of the lips. Apply the cream with your fingers to clean, dry skin. Be sure to wash your hands before and after applying Zovirax cream, and avoid bathing or swimming afterward to prevent it from washing off. Do not cover the cold sore with a bandage or make-up unless your doctor approves.

• If you miss a dose...
  Take it as soon as you remember. If it is almost time for your next dose, skip the one you missed and go back to your regular schedule. Never take 2 doses at the same time.

If you are using the ointment, apply it as soon as you remember and continue your regular schedule.

• Storage instructions...
  Store Zovirax at room temperature in a dry place.

What side effects may occur?

Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Zovirax.

• Side effects may include:
  Diarrhea, general feeling of bodily discomfort, nausea, vomiting

• Side effects of Zovirax ointment may include:
  Burning, itching, mild pain, skin rash, stinging, vaginal inflammation

• Side effects of Zovirax cream may include:
  Allergic reactions, burning, dry or cracked lips, dry or flaky skin, eczema (inflamed, irritated patches of skin), hives, inflammation, itchy spots, stinging

Why should Zovirax not be prescribed?

If you are sensitive to or have ever had an allergic reaction to Zovirax or similar drugs, you should not take Zovirax. Make sure that your doctor is aware of any drug reactions that you have experienced.

Special warnings about Zovirax

If you are being treated for a kidney disorder, consult your doctor before taking Zovirax. The drug has been known to cause kidney failure.

If you develop unusual bruising or bleeding under the skin, be sure to alert your doctor. It could signal a dangerous blood disorder.

Possible food and drug interactions when taking Zovirax

If Zovirax is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Zovirax with the following:

Cyclosporine
Interferon
Probenecid
Zidovudine

Special information if you are pregnant or breastfeeding

Zovirax seems relatively safe during pregnancy. Nevertheless, it should be used only if its benefits outweigh the potential risk to the baby. If you are pregnant or plan to become pregnant, inform your doctor immediately. Zovirax appears in breast milk and could affect a nursing infant. If Zovirax is essential to your health, your doctor may advise you to discontinue breastfeeding your baby until your treatment with Zovirax is finished.

Recommended dosage for Zovirax

ADULTS

For Genital Herpes

The usual dose is one 200-milligram capsule or 1 teaspoonful of liquid every 4 hours, 5 times daily for 10 days. If the herpes is recurrent, the usual adult dose is 400 milligrams (two 200-milligram capsules, one 400-milligram tablet or 2 teaspoonfuls) 2 times daily for up to 12 months.

If genital herpes is intermittent, the usual adult dose is one 200-milligram capsule or 1 teaspoon of liquid every 4 hours, 5 times a day for 5 days. Therapy should be started at the earliest sign or symptom.

Ointment: Apply ointment to affected area every 3 hours, 6 times per day, for 7 days. Use enough ointment (approximately one-half inch ribbon of ointment per 4 square inches of surface area) to cover the affected area.

For Herpes Cold Sores

Apply Zovirax cream to the affected area 5 times a day for 4 days. Therapy should begin as soon as possible after the first sign of a cold sore such as a bump, tingling, redness, or itchiness.

For Herpes Zoster (Shingles)

The usual adult dose is 800 milligrams (one 800-milligram tablet or 4 teaspoonfuls of liquid) every 4 hours, 5 times daily for 7 to 10 days.

For Chickenpox:

The usual adult dose is 800 milligrams 4 times a day for 5 days.

If you have a kidney disorder, the dose will need to be adjusted by your doctor.

CHILDREN

The usual dose for chickenpox in children 2 years of age and older is 20 milligrams per 2.2 pounds of body weight taken orally 4 times daily, for a total of 80 milligrams per 2.2 pounds, for 5 days. A child weighing more than 88 pounds should take the adult dose.

The safety and effectiveness of oral Zovirax have not been established in children under 2 years of age. However, your doctor may decide that the benefits of Zovirax outweigh the potential risks. The safety and effectiveness of Zovirax ointment in children have not been established. Zovirax cream has not been studied in children less than 12 years old.

OLDER ADULTS

Your doctor will start you at the low end of the dosage range, since older adults are more apt to have kidney problems or other disease, or to be taking other medications.

Overdosage

Zovirax is generally safe. However, any medication taken in excess can have serious consequences. If you suspect an overdose, seek medical attention immediately.

• Symptoms of Zovirax overdose may include:
  Agitation, kidney failure, lethargy, coma, seizures