Allopurinol (Generic)

What is Allopurinol?
Allopurinol is given to prevent bladder stones (urate stones) in multiple species including cats and dogs. It is a prescription medication that decreases the amount of uric acid produced in the body.

Who is it for?
Allopurinol is for multiple species including cats and dogs.

What are the benefits?

How does Allopurinol work?
Allopurinol decreases the amount of uric acid produced in the body. To treat and prevent bladder stones, it should be used with a diet that is low in purines (except in English bulldogs). Purines are generally higher in high-protein foods. In the body, purines are converted to uric acid. Allopurinol blocks this conversion.

Is there a generic equivalent available?
This is a generic medication.

How is it given?
Allopurinol tablets are given by mouth. Always follow the dosage instructions provided by your veterinarian. If you have difficulty giving the medication, contact your veterinarian. Encourage your pet to drink plenty of water.

This medication should only be given to the pet for whom it was prescribed.

What results can I expect?
It may take weeks to months of therapy for a bladder stone to dissolve. Allopurinol will not cure the underlying problem that caused the development of the stone(s). Allopurinol is generally not given long-term, unless the condition is severe and the diet can be closely monitored.

What form(s) does it come in?
Tablet.

Please click on "More Information" for possible drug and food interactions with this medication.

Brand Name
Zyloprim

Pronunciation
Al-loh-PURE-i-nole

Common Drug Name
Allopurinol

What should I discuss with my veterinarian while considering Allopurinol?
Talk to your veterinarian about what type of outcome is expected. Have your veterinarian explain the other treatment options and diet changes that will be necessary to treat your pet's condition.

Tell your veterinarian if your pet has a history of liver or kidney disease or is pregnant or nursing.

Notify your veterinarian of any other medications or supplements your pet is taking and also if your pet has had any reactions to previous medications.

What should I do if I miss a dose?
If you miss a dose, give it as soon as you remember. If it is almost time for the next dose, skip the one you missed and go back to the regular schedule. Do not give two doses at once.

What is the most important information I should know?
Allopurinol can cause damaging side effects if it is not used with a diet that is low in purines. Carefully follow your veterinarian's directions on Allopurinol dosage and diet.

Who should not take it?
Not for use in animals hypersensitive (allergic) to Allopurinol, or who have had a serious reaction to it.

Use with caution, lower doses, and intense monitoring in animals with liver or kidney disease.

The safety of Allopurinol in pregnant or breeding animals has not been determined. Allopurinol may be excreted in the milk, so use with caution in animals nursing young.

What side effects may be seen when taking Allopurinol?
Side effects are rare in animals if used in conjunction with a low purine diet.

How is it stored?
Store at room temperature in a tight, light-resistant, childproof container. Keep out of reach of children and pets.

What should I do if I know of or suspect there has been an overdose?
If you know or suspect your pet has had an overdose, contact your veterinarian immediately.

What should I avoid when giving my pet Allopurinol?
Consult your veterinarian before using Allopurinol with vitamins, supplements, cyclophosphamide, probenecid, sulfinpyrazone, diuretics (e.g., furosemide, Salix, Lasix), aminophylline, theophylline, amoxicillin, ampicillin, azathioprine, warfarin, mercaptopurine, trimethoprim/sulfamethoxazole, urine acidifiers (such as methionine and ammonium chloride), and with food meant to acidify the urine or with food high in purine.

Where is more information available?
Ask your veterinarian, consult with one of our pharmacists at 1-800-447-3021, or see the Patient Information Sheet on this medication.