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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.

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What is the price of this medication and similar alternatives?

This pricing information is subject to change at the sole discretion of DS Pharmacy. For the most current and up-to-date pricing information, please visit drugstore.com.

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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. Tell your doctor about any unusual or bothersome side effect.

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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.

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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.

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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.

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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.

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Can I take this if I am pregnant or trying to get pregnant or if I am breastfeeding?

Acyclovir has been assigned to pregnancy category B by the FDA. Nonstandard animal studies have produced fetal abnormalities, while standard animal testing failed to reveal evidence of teratogenicity. There are no controlled data in human pregnancy. Acyclovir is only recommended for use during pregnancy when benefit outweighs risk.

Studies to determine the pharmacokinetics and tolerability of acyclovir given near term have reported maternal-cord ratios of 0.6 to 1.9 at delivery. The pharmacokinetics of acyclovir are not significantly affected by pregnancy. No toxicity has been reported in mother or neonates. The Acyclovir in Pregnancy Registry was established in 1984 by the manufacturer and the Centers for Disease Control and Prevention (CDC) and completed in April 1999. The incidence of adverse events reported, in the 749 pregnancies followed in women exposed to systemic acyclovir during the first trimester of pregnancy resulting in 756 outcomes, approximates that of the general population. Given the small size of the registry there are no sufficient data to assess the safety of acyclovir in pregnant women and the fetus. Women exposed to systemic acyclovir during pregnancy may contact the Registry by calling GlaxoSmithKline, Inc., at (888) 825-5249. In the U.S. Michigan Medicaid study involving surveillance of 229,101 pregnancies from 1985 to 1992, there were 478 first trimester exposures to systemic acyclovir. Eighteen major birth defects were reported (versus 20 expected), including cardiovascular defects, polydactyly, limb reduction, and hypospadia. There was no evidence of an association between first trimester use of acyclovir and major groups of malformations. Acyclovir use has also been studied in five patients prior to delivery to determine the effects on asymptomatic shedding of the virus and vertical transmission to the neonate. Asymptomatic shedding and viral transmission to the infant occurred in one case. The CDC recommend the use of intravenous acyclovir in pregnant patients for the treatment of life-threatening herpes infections, including encephalitis, pneumonitis and hepatitis. Acyclovir has also been recommended for the treatment of severe or progressive maternal varicella infection. However, the use of acyclovir during pregnancy for non-life-threatening infections or for suppressive therapy is not recommended by the CDC. Primary herpes simplex infection during pregnancy has been treated with acyclovir, although this practice remains controversial. Some have suggested that acyclovir decreases the incidence of adverse pregnancy outcomes such as prematurity and growth retardation.

Acyclovir is excreted into and concentrated in human milk. Adverse effects in breast-feeding infants associated with exposure to acyclovir via breast milk have not been reported in the literature. Acyclovir is considered compatible with breast-feeding by the American Academy of Pediatrics. Moreover, acyclovir is used to treat viral infections in neonates.

In one woman, measurement of breast milk levels revealed her infant was exposed to 1% of the maternal dosage, or 0.73 mg/kg/day. No adverse effects were noted in this breast-feeding infant.

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Who should NOT use this medication?

• Known hypersensitivity to acyclovir or valacyclovir.

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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.

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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.

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Can I stop taking the medication if I feel better?
If you have been diagnosed with a disease for which an antibiotic is needed, you must complete the prescribed course of treatment. Even if you start to feel better, do not skip any doses and remember to take the medication until it is all gone.

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I am on so many medications; do I have to take them all?
This is called polypharmacy—many different medications being used at the same time by one person. Sometimes, being on multiple medications is acceptable and appropriate but at other times it may be problematic. If you are receiving your medications from multiple physicians you need to ensure that they all know what medications you are taking. The best way to do this is to make a list of all the medications you are currently using, including all nutritional supplements, homeopathic remedies, vitamins and over-the-counter drugs (if possible, also include all the diseases you have been diagnosed with). Give a copy to every doctor who takes care of you so they have it on file, this way they can avoid duplicating medications and perhaps even try to consolidate some. After every doctor's visit remember to update the list accordingly. Also, as much as you possibly can, try to use the same pharmacy to fill all your prescriptions, this way any potential drug interactions can be caught and averted.

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Where can I get more information?
More Information

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