Valtrex

DRUG DESCRIPTION

VALTREX (valacyclovir hydrochloride) is the hydrochloride salt of the L-valyl ester of the antiviral drug acyclovir.

VALTREX (valacyclovir hydrochloride) Caplets are for oral administration. Each caplet contains valacyclovir hydrochloride equivalent to 500 mg or 1 gram valacyclovir and the inactive ingredients carnauba wax, colloidal silicon dioxide, crospovidone, FD&C Blue No. 2 Lake, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, povidone, and titanium dioxide. The blue, film-coated caplets are printed with edible white ink.

The chemical name of valacyclovir hydrochloride is L-valine, 2-[(2-amino-1,6-dihydro-6oxo-9H-purin-9-yl)methoxy]ethyl ester, monohydrochloride. It has the following structural formula:

VALTREX (valacyclovir hydrochloride) Structural Formula Illustration

Valacyclovir hydrochloride is a white to off-white powder with the molecular formula C13H20N6O4•HCl and a molecular weight of 360.80. The maximum solubility in water at 25°C is 174 mg/mL. The pkas for valacyclovir hydrochloride are 1.90, 7.47, and 9.43.

What are the possible side effects of valacyclovir (Valtrex)?

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.

Stop taking valacyclovir and call your doctor right away if you have any of the following signs of a serious side effect that can harm red blood cells:

  • fever, easy bruising or bleeding;
  • red spots on the skin (not related to herpes or chickenpox);
  • bloody diarrhea, vomiting;
  • pale or yellowed skin;
  • weakness or...

Read All Potential Side Effects and See Pictures of Valtrex »

What are the precautions when taking valacyclovir hydrochloride (Valtrex)?

See also Side Effects section.

Before taking valacyclovir, tell your doctor or pharmacist if you are allergic to it; or to acyclovir; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney problems.

This drug may rarely make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.

Older adults may be more sensitive to the side effects of this drug, especially mental/mood changes (such as confusion, agitation) and kidney...

Read All Potential Precautions of Valtrex »


Valtrex Consumer (continued)

SIDE EFFECTS: Nausea, stomach pain, headache, or dizziness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: mental/mood changes (such as agitation, confusion, hallucinations), trouble speaking, shaky/unsteady movements, change in the amount of urine.

This medication may rarely cause a life-threatening disorder that affects the blood cells, kidneys, and other parts of the body. This disorder is more likely to occur if you have conditions related to a weakened immune system (such as HIV disease, bone marrow transplant, kidney transplant). Get medical help right away if you have any serious side effects, including: extreme tiredness, slow/fast/irregular heartbeat, easy bruising/bleeding, new fever, bloody/dark urine, severe stomach/abdominal pain, yellowing eyes/skin, sudden vision changes, loss of consciousness, seizures.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: See also Side Effects section.

Before taking valacyclovir, tell your doctor or pharmacist if you are allergic to it; or to acyclovir; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney problems.

This drug may rarely make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.

Older adults may be more sensitive to the side effects of this drug, especially mental/mood changes (such as confusion, agitation) and kidney problems (such as a change in the amount of urine).

Cold sores can spread easily. Avoid close physical contact with others (such as kissing) during an outbreak until the cold sores have completely healed. Try not to touch the cold sore. If you do, wash your hands afterward.

Valacyclovir does not prevent the spread of herpes. To lower the chance of giving genital herpes to your partner, do not have sexual contact during an outbreak or if you have symptoms. You can spread genital herpes even if you do not have symptoms. Therefore, always use an effective barrier method (latex or polyurethane condoms/dental dams) during all sexual activity. Consult your doctor or pharmacist for more details.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This medication passes into breast milk, but is unlikely to harm a nursing infant. Consult your doctor before breast-feeding.


Valtrex Patient Information Including Side Effects

Brand Names: Valtrex

Generic Name: valacyclovir (Pronunciation: val a SYE kloe veer)

  • What is valacyclovir (Valtrex)?
  • What are the possible side effects of valacyclovir (Valtrex)?
  • What is the most important information I should know about valacyclovir (Valtrex)?
  • What should I discuss with my healthcare provider before taking valacyclovir (Valtrex)?
  • How should I take valacyclovir (Valtrex)?
  • What happens if I miss a dose (Valtrex)?
  • What happens if I overdose (Valtrex)?
  • What should I avoid while taking valacyclovir (Valtrex)?
  • What other drugs will affect valacyclovir (Valtrex)?
  • Where can I get more information?

What is valacyclovir (Valtrex)?

Valacyclovir is an antiviral drug. It slows the growth and spread of the herpes virus so that the body can fight off the infection. Valacyclovir will not cure herpes, but it can lessen the symptoms of the infection.

Valacyclovir is used to treat infections caused by herpes viruses in adults and children. Illnesses caused by herpes viruses include genital herpes, cold sores, shingles, and chickenpox.

Valacyclovir is used to treat cold sores in children who are at least 12 years old, and to treat chickenpox in children who are at least 2 years old.

Valacyclovir may also be used for other purposes not listed in this medication guide.

What are the possible side effects of valacyclovir (Valtrex)?

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.

Stop taking valacyclovir and call your doctor right away if you have any of the following signs of a serious side effect that can harm red blood cells:

  • fever, easy bruising or bleeding;
  • red spots on the skin (not related to herpes or chickenpox);
  • bloody diarrhea, vomiting;
  • pale or yellowed skin;
  • weakness or fainting; or
  • urinating less than usual or not at all.

Call your doctor at once if you have any of these other serious side effects:

  • pain in your lower back;
  • drowsiness, mood changes, increased thirst, loss of appetite, nausea and vomiting;
  • swelling, weight gain, feeling short of breath;
  • confusion, agitation, aggression, hallucinations, trouble concentrating;
  • feeling shaky or unsteady;
  • problems with speech or vision; or
  • seizure (convulsions).

Less serious side effects may include:

  • nausea, stomach pain;
  • headache, dizziness, tired feeling, depression;
  • joint pain;
  • menstrual pain;
  • mild skin rash; or
  • stuffy nose, sore throat.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

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

Before taking valacyclovir, tell your doctor if you have HIV/AIDS, a weak immune system, kidney disease (or if you are on dialysis), or if you have had a kidney or bone marrow transplant.

Valacyclovir can be harmful to the kidneys, and these effects are increased when it is used together with other medicines that can harm the kidneys. Tell your doctor about all other medications you are using. You may need dose adjustments or special tests when taking certain medications together with valacyclovir.

Treatment with valacyclovir should be started as soon as possible after the first appearance of symptoms (such as tingling, burning, blisters).

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.

Valacyclovir will not prevent the spread of genital herpes. Herpes infections are contagious and you can infect other people even while you are taking with valacyclovir.

Stop taking valacyclovir and call your doctor right away if you have any signs of a serious side effect that can harm red blood cells, such as: fever, easy bruising or bleeding, red spots on the skin (not related to herpes or chickenpox), bloody diarrhea, vomiting, pale or yellowed skin, weakness, fainting, or urinating less than usual or not at all.

Do not give valacyclovir to a child unless it has been prescribed by a doctor.

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