ZOVIRAX

Zovirax is the brand name for acyclovir, a synthetic nucleoside analogue active against herpesviruses. Zovirax Capsules, Tablets, and Suspension are formulations for oral administration. Each capsule of Zovirax contains 200 mg of acyclovir and the inactive ingredients corn starch, lactose, magnesium stearate, and sodium lauryl sulfate. The capsule shell consists of gelatin, FD&C Blue No. 2, and titanium dioxide. May contain one or more parabens. Printed with edible black ink.

Each 800-mg tablet of Zovirax contains 800 mg of acyclovir and the inactive ingredients FD&C Blue No. 2, magnesium stearate, microcrystalline cellulose, povidone, and sodium starch glycolate.

Each 400-mg tablet of Zovirax contains 400 mg of acyclovir and the inactive ingredients magnesium stearate, microcrystalline cellulose, povidone, and sodium starch glycolate.

Each teaspoonful (5 mL) of Zovirax Suspension contains 200 mg of acyclovir and the inactive ingredients methylparaben 0.1% and propylparaben 0.02% (added as preservatives), carboxymethylcellulose sodium, flavor, glycerin, microcrystalline cellulose, and sorbitol.

Acyclovir is a white, crystalline powder with the molecular formula C8H11N5O3 and a molecular weight of 225. The maximum solubility in water at 37°C is 2.5 mg/mL. The pka’s of acyclovir are 2.27 and 9.25.

The chemical name of acyclovir is 2-amino-1,9-dihydro-9-[(2-hydroxyethoxy)methyl]-6H-purin-6-one; it has the following structural formula:

Zovirax Cream and Breastfeeding: An Overview
It is unlikely that Zovirax® cream (acyclovir cream) will cause any problems for women who are breastfeeding or for their nursing infant. However, women who are breastfeeding should be aware of a few precautions with regards to Zovirax cream.

Zovirax Cream and Breastfeeding: What Does the Research Say?
Studies have shown that acyclovir (the active ingredient of Zovirax cream) passes through breast milk. However, these studies used acyclovir that was taken by mouth or intravenously (through an IV). With Zovirax cream, only a small amount of acyclovir is absorbed through the skin into the bloodstream, meaning that it is highly unlikely that the medication would cause any problems during breastfeeding. Many healthcare providers consider it safe for nursing women. However, if your healthcare provider recommends taking Zovirax cream while breastfeeding, you should still watch for any side effects in your child.

You may want to consider stopping breastfeeding if your herpes lesions are on or near your breasts, because the infection (and the Zovirax cream) could be spread to your nursing infant.

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./p>