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Valtrex

(valacyclovir)

In this factsheet:
• How does Valtrex work? What will it do for me?
• How should I use Valtrex?
• What form(s) does Valtrex come in?
• Who should NOT take Valtrex?
• What side effects are possible with Valtrex?
• Are there any other precautions or warnings for Valtrex?
• What other drugs could interact with Valtrex?

DIN (Drug Identification Number)

What side effects are possible with Valtrex?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal pain
• constipation
• diarrhea
• dizziness
• dry mouth
• flu-like symptoms
• gas
• headache
• heartburn
• joint pain
• loss of appetite
• nausea or vomiting
• skin rash

Contact your doctor as soon as possible if any of the following occur:

• depression
• easy bruising or bleeding
• fast heartbeat

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a serious allergic reaction, such as swelling of face or throat, hives, or difficulty breathing
• signs of a severe skin reaction, such as high fever; rash, sores, or painful blisters on the skin, mouth, or eyes; or skin peeling off

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for Valtrex?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Immunosuppression (weak immune system): People who have a weakened immune system should only use valacyclovir if the benefits outweigh the risks.

Kidney disease: People with kidney disease may need a lower dose of this medication.

Safer sex: Valacyclovir, when taken in appropriate doses each day, can reduce the risk of passing on genital herpes to sexual partners. It should be used in combination with safer sex practices such as using condoms and dental dams. If you have any questions about practicing safer sex, speak to your doctor.

Pregnancy: The safety of valacyclovir use during pregnancy has not been established. It should be used during pregnancy only if benefits outweigh risks.

Breast-feeding: If you are a breast-feeding mother and are taking valacyclovir, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

What other drugs could interact with Valtrex?

There may be an interaction between valacyclovir and any of the following:

• cimetidine
• probenecid

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

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