Allopurinol

What is allopurinol?

Allopurinol is a medicine used to decrease the amount of uric acid made in the body. It may be used for medical problems that can occur if too much uric acid is in the body.​​​

You may hear allopurinol called by its brand names, Zyloprim or Purinol. Allopurinol comes as tablets and as a liquid (suspension).

Before giving allopurinol to your child?

Tell your doctor if your child has ever reacted badly to allopurinol or any other medications.

Also, talk with your doctor or pharmacist if your child has any of the following conditions. This medicine may not be right for your child if they:

• has a history of kidney problems

How should you give your child allopurinol?

• Give your child allopurinol exactly as your doctor or pharmacist tells you.
• You may give the tablets whole. If your child cannot swallow a whole tablet, you may crush the tablets and mix them with some liquid (such as water or fruit juice), or a small amount of food. Alternatively, the liquid form of allopurinol may be used.
• If your child is taking liquid allopurinol, measure the dose with the special spoon or syringe that the pharmacist gave you.
• Shake the liquid allopurinol well before you give your child each dose.
• Have your child drink plenty of fluid while taking allopurinol. Your child'​s doctor or nurse will tell you how much fluid your child needs.
• Have your child take allopurinol with food or milk to decrease the chance of stomach upset.

What should you do if your child misses a dose?

• Give the missed 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.
• Do not give your child 2 doses to make up for 1 missed dose.

What are the possible side effects of allopurinol?

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

• upset stomach (nausea) or throwing up (vomiting)
• watery bowel movements (diarrhea)
• drowsiness
• headache

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

• a rash, redness, itchy skin, or hives
• fever, chills, muscle aches or pains, or sore throat
• blood in the urine or stools
• black, tarry stools
• unusual bruising or bleeding
• difficult or painful urination
• decreased amount of urine
• yellow eyes or skin
• shortness of breath, trouble breathing, or tightness in the chest

What safety measures should you take when your child is using allopurinol?

• Allopurinol may affect the way the body handles certain drugs, including 6-mercaptopurine (6MP) and azathioprine. Be sure to tell your doctor or pharmacist if your child is using these medicines.
• Drugs such as diuretics (water pills) may increase the amount of allopurinol in the body. Tell your doctor or pharmacist if your child is using a diuretic, such as furosemide, Lasix, hydrochlorothiazide, Aldactazide, spironolactone, or metolazone.
• The antibiotics amoxicillin (Amoxil) and ampicillin may increase the chance of rash with allopurinol. Tell your doctor or pharmacist if your child is using these medications.
• Allopurinol may also affect the way the body handles blood thinners. Tell your doctor or pharmacist if you​r child is using medications such as ASA (Aspirin) or warfarin (Coumadin).

Allopurinol may make your child drowsy or less alert than normal. Watch carefully when your child is doing something that they need to be alert for, such as climbing stairs.

Do not give your child anything that may make the urine more acidic. For example, taking too much vitamin C may make the urine more acidic and increase the possibility of kidney stones forming while taking allopurinol.

Check with your child's doctor or pharmacist before giving your child any other medicines (prescription, non-prescription, or herbal products).

What other important information should you know about allopurinol?

• Keep all appointments at the clinic or doctor's office so that the doctor can check your child's reaction to allopurinol.
• Allopurinol liquid must be made by a pharmacy. Make sure your pharmacy is able to make it for your child.
• Keep a list of all medications your child is on to show the doctor or pharmacist.
• Do not share your child's medicine with others. Do not give anyone else's medicine to your child.
• Make sure you always have enough allopurinol to last through weekends, holidays, and vacations. Call your pharmacy at least 2 days before your child runs out of medicine to order refills.
• Store allopurinol tablets and liquid at room temperature in a cool, dry place away from sunlight.
• 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 allopurinol out of your child’s sight and reach and locked up in a safe place. If your child takes too much allopurinol, 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.