Drugs A - Z

Valacyclovir Hydrochloride Oral tablet

It is used to treat or prevent infections caused by certain kinds of viruses

Generic Name: valacyclovir  |  Brand Name: Valtrex

Brand Names: Valtrex

What is this medicine?

VALACYCLOVIR (val ay SYE kloe veer) is an antiviral medicine. It is used to treat or prevent infections caused by certain kinds of viruses. Examples of these infections include herpes and shingles. This medicine will not cure herpes.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:
  • acquired immunodeficiency syndrome (AIDS)
  • any other condition that may weaken the immune system
  • bone marrow or kidney transplant
  • kidney disease
  • an unusual or allergic reaction to valacyclovir, acyclovir, ganciclovir, valganciclovir, other medicines, foods, dyes, or preservatives
  • pregnant or trying to get pregnant
  • breast-feeding

How should I use this medicine?

Take this medicine by mouth with a glass of water. Follow the directions on the prescription label. You can take this medicine with or without food. Take your doses at regular intervals. Do not take your medicine more often than directed. Finish the full course prescribed by your doctor or health care professional even if you think your condition is better. Do not stop taking except on the advice of your doctor or health care professional.

Talk to your pediatrician regarding the use of this medicine in children. While this drug may be prescribed for children as young as 2 years for selected conditions, precautions do apply.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medicine?

  • cimetidine
  • probenecid

What should I watch for while using this medicine?

Tell your doctor or health care professional if your symptoms do not start to get better after 1 week.

This medicine works best when taken early in the course of an infection, within the first 72 hours. Begin treatment as soon as possible after the first signs of infection like tingling, itching, or pain in the affected area.

It is possible that genital herpes may still be spread even when you are not having symptoms. Always use safer sex practices like condoms made of latex or polyurethane whenever you have sexual contact.

You should stay well hydrated while taking this medicine. Drink plenty of fluids.

What side effects may I notice from receiving this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:
  • allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
  • aggressive behavior
  • confusion
  • hallucinations
  • problems with balance, talking, walking
  • stomach pain
  • tremor
  • trouble passing urine or change in the amount of urine

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):

  • dizziness
  • headache
  • nausea, vomiting

Where should I keep my medicine?

Keep out of the reach of children.

Store at room temperature between 15 and 25 degrees C (59 and 77 degrees F). Keep container tightly closed. Throw away any unused medicine after the expiration date.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.


Last Updated: February 23, 2009
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