What to avoid when taking allopurinol?

October 8, 2025 •

3 min read

Studies show that less than 50% of patients taking allopurinol, a primary medication for gout, achieve the target uric acid concentration. Understanding what to avoid when taking allopurinol is crucial for treatment success and safety.

Quick Summary

To maximize the benefits of allopurinol, it's essential to avoid certain medications like specific diuretics and antibiotics, limit alcohol, and follow a diet low in purines to help manage uric acid levels effectively.

Key Points

Diet is Key: While allopurinol works, a diet high in purines from red meat, certain seafood, and organ meats can counteract its effects.
Limit Alcohol and Sugar: Alcohol, especially beer, and drinks with high-fructose corn syrup can increase uric acid and trigger gout attacks.
Beware of Drug Interactions: Allopurinol can have serious interactions with common medications like certain diuretics (hydrochlorothiazide), ACE inhibitors, and antibiotics (amoxicillin).
Do Not Stop During a Flare: If a gout attack occurs, continue taking allopurinol and consult your doctor for anti-inflammatory medication to manage the flare.
Watch for Serious Rash: A spreading rash with fever or blisters can be a sign of a rare but life-threatening reaction (SJS/DRESS) and requires immediate medical attention.
Stay Hydrated: Drinking plenty of water is essential to help your kidneys remove uric acid and prevent the formation of kidney stones.
Inform Your Doctor: Always provide your healthcare provider with a complete list of all medications you take, including over-the-counter drugs and supplements, to avoid dangerous interactions.

Allopurinol is a cornerstone medication for managing conditions caused by high uric acid levels, most notably gout. It works by inhibiting xanthine oxidase, the enzyme responsible for producing uric acid. While highly effective, its success depends on careful management of diet, lifestyle, and other medications. Certain substances can interact with allopurinol, either reducing its efficacy or increasing the risk of adverse effects. Therefore, patients must be aware of what to avoid to ensure their treatment is both safe and effective. Taking allopurinol after a meal may help reduce stomach upset.

Dietary and Lifestyle Adjustments

While no foods directly interact with allopurinol to neutralize the drug, some foods and drinks can increase the body's uric acid levels, potentially triggering gout attacks.

High-Purine Foods

Purines, found in many foods, are broken down into uric acid. High-purine foods can lead to uric acid buildup in people with gout, counteracting allopurinol's effect. Limiting certain foods is advisable:

Red Meats
Organ Meats
Certain Seafood (anchovies, sardines, mussels, scallops, trout, and tuna)

Sugary Foods and Alcohol

High-fructose corn syrup can raise uric acid levels. Alcohol increases uric acid production and hinders its elimination, with beer being particularly high in purines. It is best to adhere to national guidelines for alcohol consumption or avoid it, as it may also worsen side effects like drowsiness.

Hydration and Activities

Good hydration helps kidneys clear uric acid and prevent kidney stones. Due to potential drowsiness or dizziness, especially when starting treatment, avoid mentally demanding activities like driving until you know how the medication affects you.

Significant Medication Interactions

Allopurinol can interact with several medications, potentially causing serious health issues. Always inform your healthcare provider about all medications you are taking.


Interacting Drug Class/Name	Potential Interaction with Allopurinol	Management Recommendation
Azathioprine & Mercaptopurine	Increases levels of these drugs, raising the risk of toxicity.	Dose reduction and close monitoring required.
Thiazide Diuretics (e.g., Hydrochlorothiazide)	Increases risk of allopurinol side effects, including rash.	Close monitoring necessary.
ACE Inhibitors (e.g., Lisinopril, Captopril)	Can increase the risk of serious skin reactions (Stevens-Johnson syndrome).	Caution and monitoring for rash essential.
Penicillin Antibiotics (e.g., Amoxicillin, Ampicillin)	Increases the incidence of skin rash.	Stop allopurinol and contact doctor if rash develops.
Warfarin	Can enhance the blood-thinning effect, increasing bleeding risk.	More frequent blood tests (INR) and dose adjustment needed.

Understanding and Managing Side Effects

Experiencing a gout flare is possible, particularly when starting allopurinol. Do not stop allopurinol during a flare, as this can worsen the attack. Your doctor can prescribe anti-inflammatory medications like colchicine or NSAIDs for acute flares.

Serious skin reactions (SCARs) like DRESS and SJS are rare but life-threatening side effects of allopurinol. Seek immediate medical help for symptoms such as fever, sore throat, a spreading purplish rash, blisters, or skin shedding, especially in the initial months of treatment. Risk factors include the HLA-B*58:01 genetic allele and pre-existing kidney disease.

Conclusion

Effective gout management with allopurinol requires careful attention to diet, lifestyle, and potential drug interactions. Limiting high-purine foods, sugary drinks, and alcohol is important. Patients should be aware of interactions with diuretics, certain antibiotics, and blood thinners, and always inform their doctor of all medications. Understanding what to avoid and managing side effects helps improve treatment outcomes and reduce adverse events. For more information, consult authoritative sources like the {Link: NHS page on allopurinol https://www.nhs.uk/medicines/allopurinol/}.

Frequently Asked Questions

While no food needs to be completely avoided just because of the medication itself, it's highly recommended to limit foods high in purines to help manage your gout. These include organ meats (liver, kidneys), some seafood like anchovies and sardines, and red meat.

While alcohol doesn't directly interact with the medicine, it's best to limit or avoid it. Alcohol, particularly beer, increases uric acid levels, which can trigger the gout attacks that allopurinol is meant to prevent.

Do not stop taking allopurinol. Abruptly stopping can make the flare-up worse. Contact your doctor; they will likely prescribe an additional medication, like an NSAID or colchicine, to treat the acute pain and inflammation.

You should avoid taking aspirin for pain, as it can worsen a gout flare. Pain relievers like ibuprofen and naproxen are generally considered acceptable for managing a flare, but always confirm with your doctor.

Drinking plenty of water helps your body flush out uric acid through the kidneys. This aids the medication's effectiveness and helps prevent the formation of uric acid or xanthine kidney stones.

A serious reaction is rare but requires immediate medical attention. Symptoms include a severe, spreading skin rash (often purplish and blistering), fever, sore throat, and peeling skin. These may be signs of life-threatening conditions like Stevens-Johnson syndrome (SJS) or DRESS syndrome.

It depends on the medication. Allopurinol can interact with certain blood pressure drugs, specifically thiazide diuretics and ACE inhibitors, increasing the risk of side effects or a hypersensitivity reaction. It is crucial to discuss all your medications with your doctor.