Valtrex

Generic name: Valacyclovir hydrochloride

What is Valtrex?

Valtrex is a prescription antiviral medication that lowers the ability of herpes viruses to multiply in your body. It is used to treat cold sores, shingles, control (and treat) genital herpes infections in adults with healthy immune systems, control genital herpes infections in patients with HIV, and, along with safer sex practices, to help reduce the transmission of genital herpes. It can also be used to treat chickenpox for children ages 12-18 with healthy immune systems.

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

Valtrex may cause life-threatening blood disorders, especially when taken at high doses and in patients with advanced HIV (human immunodeficiency virus) disease, or those undergoing allogenic bone marrow or kidney transplants. You should use caution when taking Valtrex if you have kidney problems or are elderly. It is not known if Valtrex can reduce the transmission of genital herpes if you have multiple sexual partners or in nonheterosexual couples. Valtrex does not cure genital herpes. You should avoid sexual contact if you have open lesions or an active outbreak; however, genital herpes may be spread even if you have no symptoms of an outbreak. You should always use a condom made of latex or polyurethane whenever you have sexual contact. If your doctor advises you to take Valtrex for recurrent outbreaks, start taking it at the first sign or symptom of an outbreak. If taking Valtrex to treat cold sores, you should take the first dose at the first sign or symptom, but not for longer than 1 day.

Who should not take Valtrex?

You should not take Valtrex if you are allergic to acyclovir or any ingredients in Valtrex.

What should I tell my doctor before I take the first dose of Valtrex?

Mention all prescription, over-the-counter, and herbal medications you are taking before beginning treatment with Valtrex. Also, talk to your doctor about your complete medical history, especially if you have had a bone marrow transplant or kidney transplant, or if you have advanced HIV disease or AIDS (Acquired Immunodeficiency Syndrome), if you have kidney problems, are over 65 years old, if you are pregnant or are planning to become pregnant, or if you are breastfeeding.

What is the usual dosage?

The information below is based on the dosage guidelines your doctor uses. Depending on your condition and medical history, your doctor may prescribe a different regimen. Do not change the dosage or stop taking your medication without your doctor's approval.

Adults: Herpes Zoster

Adults and adolescents 12 years and older: The usual dosage is 1 gram (g) taken 3 times a day for 7 days.

Genital Herpes, Initial Episodes

Adults: The usual dosage is 1 g taken 2 times a day for 10 days.

Genital Herpes, Recurrent Episodes

Adults: The usual dosage is 500 milligrams (mg) taken 2 times a day for 3 days.

Suppressive Therapy

Adults: The usual dosage is 1 g taken once daily. In patients with 9 or fewer recurrences a year, the alternative is 500 mg taken once daily. For patients with HIV who have a CD4 cell count of less than 100 cells/mm3, the usual dosage is 500 mg taken 2 times a day.

Reduction of Transmission

Adults: The usual dosage for patients with 9 or fewer episodes a year is 500 mg taken once daily.

Cold Sores (Herpes Labialis)

Adults: The usual dosage is 2 g taken 2 times a day for 1 day, each dose separated by 12 hours.

There are also a series of dosage recommendations for patients with kidney disease in the official Valtrex package insert.

Chickenpox

Children 2 years old to less than 18 years old: 20 mg/kg three times a day for 5 days; not to exceed more than 1 g three times a day.

How should I take Valtrex?

Valtrex should be taken as prescribed at the same time every day, and should not be discontinued unless directed by a healthcare provider. Valtrex may be taken with or without food. If you are taking Valtrex to treat shingles, cold sores, or genital herpes, you should start taking it as soon as you notice any symptoms of an outbreak. Do not take more Valtrex than prescribed. If you take too much, call your doctor right away.

What should I avoid while taking Valtrex?

You should avoid becoming dehydrated, so drink plenty of fluids while taking Valtrex. Do not have sexual intercourse during an outbreak. Always use a latex condom.

What are possible food and drug interactions associated with Valtrex?

If Valtrex 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 Valtrex with antacids, cimetidine, digoxin, probenecid, or thiazide diuretics.

What are the possible side effects of Valtrex?

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

Side effects may include: dizziness, headache, nausea, stomach pain, vomiting

Side effects in HIV-infected adults: headache, rash, tiredness

Can I receive Valtrex if I am pregnant or breastfeeding?

The effects of Valtrex during pregnancy and breastfeeding are unknown. Tell your doctor immediately if you are pregnant, plan to become pregnant, or are breastfeeding.

What should I do if I miss a dose of Valtrex?

If you miss a dose of Valtrex, take it as soon as you remember and then return to your normal dosing schedule. If it is almost time for your next dose, do not take the missed dose. Wait and take the next dose at the regular time.

How should I store Valtrex?

Store at room temperature in a child-resistant container.