7 Tips for Taking Allopurinol: When to Take it, What to Avoid, and How to Save

Ever woken up to a painful, swollen big toe, but don’t recall injuring it? You may be showing the first signs of a gout attack. This can be unnerving, but there are several ways to treat it.

One option is allopurinol (Zyloprim). It’s a prescription medication known as a xanthine oxidase inhibitor. It works by stopping a protein called xanthine oxidase, which plays a role in making uric acid in the body. It helps get rid of the uric acid crystals in the joints that cause gout pain.

Allopurinol helps keep uric acid levels low, which helps adults treat gout over time. It can also be useful in preventing kidney stones. A healthcare professional might also prescribe it to prevent tumor lysis syndrome (TLS) for adults and children undergoing chemotherapy.

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You’ll take allopurinol by mouth once or twice a day. But there are still a few things to know about it. Here, we’ll address when to take allopurinol, what to avoid while taking it, and other tips for starting this medication.

1. It’s best to take allopurinol after a meal

You can take allopurinol with or without food. But it's best to take it after eating a meal to help prevent stomach upset. It’s common to experience nausea and diarrhea with allopurinol.

If you develop an upset stomach after starting allopurinol, try to eat smaller, more frequent meals throughout the day. Try to avoid greasy, fatty foods and stay hydrated by drinking plenty of water. Sticking to bland foods might help, too. You should be able to go back to your typical diet once your stomach starts feeling better.

Let your healthcare professional know if your stomach issues don’t improve. They may recommend some medications to help manage it while taking allopurinol. Thankfully, stomach-related side effects typically subside as your body gets used to the medication.

2. There are ways to manage side effects from allopurinol

Most side effects of allopurinol are relatively mild. But some bothersome side effects can still pop up.

You may experience more gout flares during the first couple months of taking allopurinol. This is due to allopurinol rapidly lowering uric acid levels, which can irritate your joints and lead to more inflammation.

EXPERT PICKS: WHAT TO READ NEXT

• Managing side effects: Find out more about notable side effects of allopurinol, from an upset stomach and skin rashes to kidney harm.

• A dose of relief: A typical starting allopurinol dosage is 100 mg per day, but doses may differ for children or those with kidney problems. Find out more about allopurinol dosages here.

• Allopurinol interactions: Discover what medications may interact with allopurinol and how best to manage medication interactions.

Fortunately, you have a few options to lessen initial gout flares during this time. Your healthcare professional may prescribe you a medication called colchicine (Colcrys) at the same time as allopurinol. This helps prevent gout flares while easing joint inflammation. They may want you to take colchicine for the first few months of taking allopurinol.

Another pesky side effect to keep in mind while taking allopurinol is kidney stones. Allopurinol works to prevent kidney stones because it lowers uric acid levels, which helps prevent uric acid stones. But sometimes lowering uric acid can lead to the formation of xanthine urinary stones, a different type of kidney stone.

To help prevent kidney stones, do your best to stay hydrated. This helps your body flush out uric acid and help prevent kidney stones from forming. Ideal fluid intake varies by person, so ask your prescriber how much you should aim for on a daily basis. It also helps to avoid foods that can cause kidney stones, such as animal protein, spinach, and chocolate. 

Let your healthcare professional know right away if you experience symptoms of a kidney stone, such as back pain, nausea, or pain and burning while urinating.

3. What to avoid when taking allopurinol

Allopurinol can make you feel dizzy or sleepy. So it's best to avoid driving or doing anything that requires a significant amount of concentration until you know how allopurinol affects you.

It's also best to minimize or avoid consuming alcohol while taking allopurinol. Alcohol can make dizziness and drowsiness worse. Alcohol may also make gout flares worse.

Allopurinol may interact with several medications too. These include medications such as warfarin (Coumadin, Jantoven), which may require you to have your blood checked more frequently. Other medications, such as amoxicillin (Amoxil) and thiazide diuretics (water pills) like hydrochlorothiazide, may raise your risk of developing a rash. Allopurinol rashes can be serious, so it’s important to contact your healthcare professional if one develops.

Let your prescriber and pharmacist know about all the medications you’re taking. They can screen for any potential allopurinol interactions in advance. 

4. How to take allopurinol if swallowing pills is difficult

If swallowing pills is difficult, there are a few workarounds to consider so you can still take allopurinol.

If you struggle with large pills, you can try cutting or splitting allopurinol tablets into smaller pieces. This medication is OK to separate, and the pills are scored. You may find smaller pieces easier to swallow than a whole tablet. You can also chew allopurinol tablets, which can make swallowing them easier.

Another option is crushing allopurinol tablets and sprinkling them on top of applesauce or dissolving them in water.

5. Allopurinol injections are available for those going through cancer treatment

You might have the option to get allopurinol intravenously (through an IV, into a vein). Healthcare professionals typically reserve this option for people who have cancer and are undergoing treatment with chemotherapy. In this case, they’ll use allopurinol to prevent a serious complication of treatment called TLS.

TLS can cause a spike in uric acid levels. This is a potentially life-threatening condition that can happen when cancer cells are rapidly broken down. IV allopurinol can be especially helpful for preventing TLS if you have difficulty swallowing oral allopurinol.

IV allopurinol is usually not used for people who need to take allopurinol for gout or kidney stones. The tablet form is usually sufficient for those conditions.

6. What to do if your child or pet accidentally swallows allopurinol

If you suspect that your child accidentally swallowed allopurinol, contact their pediatrician right away. Another option is contacting Poison Control online or at 1-800-222-1222. Either one should be able to provide advice on how best to manage your specific situation. However, if your child is having trouble breathing or is unconscious, call 911 or go to the nearest ER.

If you think your pet accidentally swallowed allopurinol, contact their veterinarian. If the veterinarian is unavailable, contact an animal poison control center, such as the Pet Poison Helpline or the ASPCA Animal Poison Control Center. Your veterinarian or an animal poison control center will be able to provide advice and early intervention for your pet, if needed.

7. How to store allopurinol

You should store allopurinol at room temperature, between 68°F and 77°F (20°C to 25°C). You should also keep it away from direct sunlight.

It’s best to store medications like allopurinol in a cool, dry place where temperatures are stable. An elevated kitchen cabinet is a good place to consider. Don’t store allopurinol in places where moisture or temperature changes can happen, like in a bathroom or car. Temperature and humidity changes may affect how well allopurinol works.

It's also best to store medications out of reach of children or pets. Avoid places like low cabinets, coffee tables, and low pullout drawers.

How to save on allopurinol

Allopurinol is available as a brand-name medication and lower-cost generic. GoodRx can help you save over 70% off the average retail price of the generic version. Generic allopurinol at certain pharmacies is as low as $4.80 with a free GoodRx coupon.

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Written by:

Sonja Jacobsen, PharmD, BCPS, BCOP

Sonja Jacobsen, PharmD, BCPS, BCOP,  is a clinical oncology pharmacy specialist currently practicing in Seattle. She has been practicing as a pharmacist since 2015 and is licensed to practice in Washington state and North Carolina.

Edited by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

Reviewed by:

Jennifer Gershman, PharmD, CPh, PACS

Jennifer Gershman, PharmD, is a licensed pharmacist in Florida. She has worked in the pharmacy industry for more than 15 years and is currently a medical writer.

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