This information from Lexicomp® explains what you need to know about this medication, including what it’s used for, how to take it, its side effects, and when to call your healthcare provider.
Brand Names: US
Valtrex
Brand Names: Canada
AG-Valacyclovir; APO-Valacyclovir; Auro-Valacyclovir; BIO-Valacyclovir [DSC]; DOM-Valacyclovir [DSC]; JAMP Valacyclovir; JAMP-Valacyclovir; Mar-Valacyclovir [DSC]; MYLAN-Valacyclovir; PMS-Valacyclovir; Priva-Valacyclovir [DSC]; PRO-Valacyclovir; RIVA-Valacyclovir; SANDOZ Valacyclovir; TEVA-Valacyclovir; Valtrex
What is this drug used for?
- It is used to treat cold sores or certain other herpes infections.
- It is used to treat chickenpox.
- It may be given to your child for other reasons. Talk with the doctor.
What do I need to tell the doctor BEFORE my child takes this drug?
- If your child is allergic to this drug; any part of this drug; or any other drugs, foods, or substances. Tell the doctor about the allergy and what signs your child had.
This drug may interact with other drugs or health problems.
Tell the doctor and pharmacist about all of your child’s drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe to give this drug with all of your child’s other drugs and health problems. Do not start, stop, or change the dose of any drug your child takes without checking with the doctor.
What are some things I need to know or do while my child takes this drug?
- Tell all of your child’s health care providers that your child is taking this drug. This includes your child’s doctors, nurses, pharmacists, and dentists.
- Do not give this drug to your child for longer than you were told by the doctor.
- If your child is taking this drug for cold sores, it will not cure cold sores. Talk with the doctor.
- This drug is not a cure for herpes infections. Talk with the doctor.
If your child is or may be sexually active:
- If your child has genital herpes, this drug will not stop it from spreading. Be sure your child does not have any kind of sex when any sores or other signs of genital herpes are present. Genital herpes can also be spread if your child does not have any signs. Be sure your child does not have any kind of sex without using a latex or polyurethane condom. Talk with the doctor.
If your child is pregnant or breast-feeding a baby:
- Talk with the doctor if your child is pregnant, becomes pregnant, or is breast-feeding a baby. You will need to talk about the benefits and risks to your child and the baby.
What are some side effects that I need to call my child’s doctor about right away?
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your child’s doctor or get medical help right away if your child has any of the following signs or symptoms that may be related to a very bad side effect:
- Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
- Signs of kidney problems like unable to pass urine, change in how much urine is passed, blood in the urine, or a big weight gain.
- Feeling confused.
- Change in the way your child acts.
- Mood changes.
- Hallucinations (seeing or hearing things that are not there).
- Trouble speaking.
- Seizures.
- Shakiness, trouble moving around, or stiffness.
- Very bad and sometimes deadly blood problems like thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS) have happened with this drug in some people. Call your child’s doctor right away if your child feels very tired or weak or has any bruising or bleeding; dark urine or yellow skin or eyes; pale skin; change in the amount of urine passed; change in eyesight; change in strength on 1 side is greater than the other, trouble speaking or thinking, or change in balance; or fever.
What are some other side effects of this drug?
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your child’s doctor or get medical help if any of these side effects or any other side effects bother your child or do not go away:
- Headache.
- Upset stomach or throwing up.
- Stomach pain.
- Diarrhea.
- Feeling tired or weak.
If your child has menstrual periods:
- Period (menstrual) pain.
These are not all of the side effects that may occur. If you have questions about side effects, call your child’s doctor. Call your child’s doctor for medical advice about side effects.
You may report side effects to your national health agency.
How is this drug best given?
Give this drug as ordered by your child’s doctor. Read all information given to you. Follow all instructions closely.
- Give this drug with or without food.
- Have your child drink lots of noncaffeine liquids every day unless told to drink less liquid by your child’s doctor.
- If your child is taking this drug to treat cold sores, chickenpox, shingles, or genital herpes, give this drug as soon as you can after your child’s signs start. This drug may not help if your child starts taking it too late.
- If your child is on dialysis and is taking this drug on the day of dialysis, give it to your child after dialysis. If you have questions, talk with your child’s doctor.
- Keep giving this drug to your child as you have been told by your child’s doctor or other health care provider, even if your child feels well.
- A liquid (suspension) can be made if your child cannot swallow pills. Talk with your child’s doctor or pharmacist.
Liquid (suspension):
- If a liquid (suspension) is made, shake well before use.
- Measure liquid doses carefully. Use the measuring device that comes with this drug. If there is none, ask the pharmacist for a device to measure this drug.
What do I do if my child misses a dose?
- Give a missed dose as soon as you think about it.
- If it is close to the time for your child’s next dose, skip the missed dose and go back to your child’s normal time.
- Do not give 2 doses at the same time or extra doses.
How do I store and/or throw out this drug?
Tablets:
- Store at room temperature in a dry place. Do not store in a bathroom.
Liquid (suspension):
- If a liquid (suspension) is made from the tablets, store in a refrigerator. Do not freeze. Throw away any part not used after 28 days.
All products:
- Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
- Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
General drug facts
- If your child’s symptoms or health problems do not get better or if they become worse, call your child’s doctor.
- Do not share your child’s drug with others and do not give anyone else’s drug to your child.
- Some drugs may have another patient information leaflet. If you have any questions about this drug, please talk with your child’s doctor, nurse, pharmacist, or other health care provider.
- If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.
Consumer Information Use and Disclaimer
This generalized information is a limited summary of diagnosis, treatment, and/or medication information. It is not meant to be comprehensive and should be used as a tool to help the user understand and/or assess potential diagnostic and treatment options. It does NOT include all information about conditions, treatments, medications, side effects, or risks that may apply to a specific patient. It is not intended to be medical advice or a substitute for the medical advice, diagnosis, or treatment of a health care provider based on the health care provider’s examination and assessment of a patient’s specific and unique circumstances. Patients must speak with a health care provider for complete information about their health, medical questions, and treatment options, including any risks or benefits regarding use of medications. This information does not endorse any treatments or medications as safe, effective, or approved for treating a specific patient. UpToDate, Inc. and its affiliates disclaim any warranty or liability relating to this information or the use thereof. The use of this information is governed by the Terms of Use, available at https://www.wolterskluwer.com/en/know/clinical-effectiveness-terms.
Last Reviewed Date
2022-12-26
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