Valtrex

valaciclovir

Valtrex is used to treat cold sores (herpes labialis), shingles (herpes zoster). It is also used to treat genital herpes in patients with a normal immune system. Valaciclovir can also be used to control genital herpes outbreaks in all patients including those with HIV. This is also known as suppressive therapy. This medication helps control symptoms, but does not cure the disease. This medication may be used to prevent or treat other types of viral infections (cytomegalovirus) in certain patient populations.

What is Valtrex?

Genital herpes is a viral infection that breaks out periodically in sores around the genitals and rectum. Valtrex is an antiviral medication that suppresses the herpes virus, preventing it from spreading to other cells in your body. Valtrex is clinically proven to reduce the number of outbreaks. It can also lower the risk of giving genital herpes to a sexual partner. Valtrex will not prevent the spread of genital herpes. Herpes infections are contagious and you can infect other people even while you are taking with Valtrex.

Before taking Valtrex

Do not take this medicine if you are allergic to valaciclovir or acyclovir (Zovirax). If you have certain conditions, you may need a dose adjustment or special tests to safely take this medication. Before taking Valtrex, tell your doctor if you have:

• HIV/AIDS, or other conditions that can weaken the immune system;
• kidney disease (or if you are on dialysis); or
• if you have had a kidney or bone marrow transplant.

How should I take Valtrex?

Take Valtrex by mouth with or without food. If stomach upset occurs, take with food to reduce stomach irritation. Drinking extra fluids while you are taking Valtrex is recommended. Check with your doctor for instructions.

To treat an outbreak of genital herpes, the usual dose of Valtrex is increased to twice daily for three days. Valtrex is most effective when taken as soon as symptoms of herpes appear. If you are taking Valtrex for shingles, you should start using it as soon as possible. It's best to start with the drug within 48 hours of first noticing the rash. If you wait more than 72 hours after you first get a herpes zoster rash, the medication may not be effective.

If you are taking Valtrex for cold sores, you should start using it at the earliest signs of infection, such as tingling, itching, or burning. If you wait until the cold sore develops, the medication might not work. You may take Valtrex with or without food. If your symptoms do not improve or if they become worse, check with your doctor.

Valtrex side effects

Common side effects associated with Valtrex include nausea, vomiting, headache, stomach pain, dizziness, cold and sore throat. Valtrex can be harmful to the kidneys, and these effects are increased when it is used together with other medicines that can harm the kidneys.

Precautions

Valaciclovir belongs to a class of medications known as antivirals. If you are taking valacyclovir for treatment of genital herpes, to lower the chance of giving herpes to your partner, it is important to follow safe sex practices even if there are no symptoms present. Always use a condom made of latex or polyurethane. When you have symptoms or are experiencing an outbreak, do not have sexual contact with your partner.

Drug interactions

Valtrex can be harmful to the kidneys, and these effects are increased when it is used together with other medicines that can harm the kidneys. Before taking Valtrex, tell your doctor if you are also using:

• lithium (Eskalith, Lithobid);
• methotrexate (Rheumatrex, Trexal);
• pain or arthritis medicines such as aspirin (Anacin, Excedrin), acetaminophen (Tylenol), diclofenac (Voltaren), etodolac (Lodine), ibuprofen (Advil, Motrin), indomethacin (Indocin), naproxen (Aleve, Naprosyn), and others;
• medicines used to treat ulcerative colitis, such as mesalamine (Pentasa) or sulfasalazine (Azulfidine);
• medicines used to prevent organ transplant rejection, such as sirolimus (Rapamune) or tacrolimus (Prograf);
• IV antibiotics such as amphotericin B (Fungizone, AmBisome, Amphotec, Abelcet), amikacin (Amikin), bacitracin (Baci-IM), capreomycin (Capastat), gentamicin (Garamycin), kanamycin (Kantrex), streptomycin, or vancomycin (Vancocin, Vancoled);
• antiviral medicines such as adefovir (Hepsera), cidofovir (Vistide), or foscarnet (Foscavir); or
• cancer medicine such as aldesleukin (Proleukin), carmustine (BiCNU, Gliadel), cisplatin (Platinol), ifosfamide (Ifex), oxaliplatin (Eloxatin), plicamycin (Mithracin), streptozocin (Zanosar), or tretinoin (Vesanoid).

Preganacy

Valtrex is not expected to be harmful to an unborn baby. Do not take this medication without first talking to your doctor if you are pregnant or could become pregnant during treatment. It is not known whether Valtrex passes into breast milk and how it may affect a nursing baby. Do not take this medication without first talking to your doctor if you are breast-feeding a baby.

Overdose

Seek emergency medical attention if you think you have used too much of this medicine. Overdose symptoms may include urinating less than usual or not at all.

Notes

This information is a summary only. It does not contain all information about Valtrex. If you have any other questions about Valtrex, please talk with your doctor, pharmacist, or other health care provider.