Acyclovir

What is acyclovir?

Acyclovir is a type of medicine called an antiviral. It is used to treat or prevent infections caused by certain types of viruses.

You may hear acyclovir called by its brand name, Zovirax. Acyclovir comes in tablet, suspension and injectable forms.​

Before giving acyclovir to your child

Tell your child's doctor if your child has had any unusual or allergic reaction to acyclovir, valacyclovir, famciclovir, or any other medicines in the past.

Also, talk with the doctor or pharmacist if your child has any of the following conditions. Precautions may need to be taken with this medicine if your child has:

• kidney problems

How should you give your child acyclovir?

• Give your child this medicine by mouth
• For as long as your doctor or pharmacist tells you, even if your child seems well. Talk to your child's doctor before you stop giving acyclovir for any reason.
• ​At the same times every day, exactly as your doctor or pharmacist tells you.
• With or without food; give it with food if it makes your child's stomach upset.
• With a glass of water or other liquid.
• It is important for your child to drink plenty of water or other liquid every day, unless they were told to drink less by the doctor.
• If giving the suspension, shake the bottle well before measuring each dose.

Acyclovir can also be given by a needle into your child's vein. It will be given by a nurse in the hospital clinic or the nursing unit.

What should you do if your child misses a dose?

• Give the miss​ed dose as soon as you remember.
• If it is almost time for the next dose, skip the missed dose. Give the next dose at the regular time.
• Give only one dose at a time.

What are the possible side effects of acyclovir?

Your child may have some of these side effects while they take acyclovir. Check with your child's doctor if your child continues to have any of these side effects, and they do not go away, or they bother your child:

• upset stomach
• vomiting (throwing up)
• diarrhea (loose stools)
• mild headache
• dizziness

Most of the following side effects are not common, but they ​​may be signs of a serious problem. Call your child'​s doctor right away or take your child to the Emergency Department if your child has any of these side effects:

• problems passing urine or passing less urine than usual
• unusual tiredness or weakness
• confusion
• seizures
• skin rash

It is important to consult with your child's doctor or pharmacist before giving your child any other medicines. These include prescription, over the counter, herbal, homeopathic, or natural remedies, supplements, or treatments. Inform your child's doctor or pharmacist if your child takes any other medicines and that your child is taking acyclovir.

What other important information should you know about acyclovir?

• If your child's symptoms do not get better in a few weeks or if they get worse, check with your child's doctor.
• Keep a list of all medicines your child is on and show the list to the doctor or pharmacist.
• Do not share your child's medicine with others. Do not give anyone else's medicine to your child.
• Keep acyclovir at room temperature, away from heat and moisture. Do not store it in the bathroom or kitchen.
• Do not keep any medicines that are out of date. Check with your pharmacist about the best way to throw away outdated or leftover medicines.
  

Keep acyclovir out of your child’s sight and reach and locked up in a safe place. If your child takes too much acyclovir, call your local Poison Information Centre at one of these numbers. These calls are free. 

• Call 1-844 POISON-X, or 1-844-764-7669, from anywhere in Canada except Quebec.
• Call 1-800-463-5060 if you live in Quebec.