Allopurinol Tablets for Gout Prevention and High Uric Acid

What Allopurinol Is and How It Works

Allopurinol is a xanthine oxidase inhibitor used to lower uric acid. It helps prevent gout flares, tophi, and uric acid kidney stones. It is taken as oral tablets, commonly available as 100 mg and 300 mg strengths. Allopurinol is used for chronic control, not for immediate pain relief during a gout flare.

CanadianInsulin is a prescription referral service. Prescriptions are verified with your clinic, and orders are filled by licensed Canadian pharmacies. We work with licensed, vetted partner pharmacies to supply authentic medications, a broad selection, and value-focused pricing.

By blocking xanthine oxidase, allopurinol reduces production of uric acid from purines. Lower serum urate helps dissolve urate crystals over time. This reduces flare frequency and protects joints and kidneys. It can also be used to prevent hyperuricemia during certain chemotherapy regimens.

Dosage and Usage

• Initiation: Many patients start at 100 mg once daily. Lower starting doses may be used with reduced kidney function.
• Titration: Dose increases typically occur every 2–5 weeks based on serum urate. Common maintenance ranges are 100–300 mg daily. Some patients require higher doses (up to 800 mg/day, usually divided).
• Target: Serum urate targets are often below 6 mg/dL (0.36 mmol/L). A lower target (below 5 mg/dL) may be used with tophi.
• Administration: Take tablets at the same time each day. Taking after food can reduce stomach upset. Maintain good hydration.
• Do not use for acute flare relief. Anti-inflammatory prophylaxis (e.g., colchicine or an NSAID) is often used during initiation to reduce flare risk.
• Missed dose: Take when remembered unless near the next dose. Skip if close to the next dose. Avoid double dosing.
• Ongoing therapy: Continue long term as directed to maintain target urate. Do not stop suddenly without medical guidance.
• Tablet handling: Swallow with water. Scored tablets may be split if needed.

• Storage: Keep tablets at 20–25°C (68–77°F). Excursions 15–30°C (59–86°F) are usually acceptable.
• Moisture: Store in a dry place. Keep the bottle tightly closed.
• Light: Protect from excessive light. Keep in original packaging when possible.
• Travel: Carry in original labeled container. Pack in a carry-on bag.
• Heat: Avoid glove boxes, dashboards, and heaters. Do not freeze.
• Supply: Bring extra doses for delays. Carry a copy of the prescription.

Benefits and Savings

Allopurinol lowers uric acid, which reduces gout flares over time. It helps shrink tophi and protects joint function. It also supports kidney health by preventing uric acid stone formation. Once-daily dosing simplifies routines and supports adherence for chronic prevention.

Many customers save 60–80% vs typical U.S. prices.

Side Effects and Safety

• Common: rash or itching, nausea, vomiting, diarrhea, stomach discomfort.
• Other: drowsiness, headache, changes in liver enzymes, altered taste.
• Gout flares may increase temporarily when therapy begins.
• Rare hematologic effects: low white blood cells or platelets.

Serious reactions can occur, including allopurinol hypersensitivity syndrome (AHS), which may involve fever, rash, liver or kidney injury, eosinophilia, and severe skin reactions such as Stevens–Johnson syndrome or toxic epidermal necrolysis. Risk is higher in carriers of HLA-B*58:01, particularly individuals of Han Chinese, Thai, or Korean descent and those with chronic kidney disease. Stop therapy and seek urgent care if severe rash or systemic symptoms appear. Important interactions include azathioprine and 6-mercaptopurine (often requiring major dose reductions), and increased effects of warfarin and theophylline. Thiazide diuretics, such as Hydrochlorothiazide, may raise uric acid and increase hypersensitivity risk. Alcohol can elevate urate and trigger flares.

Onset Time

Uric acid levels usually begin to fall within a few days of starting therapy. Consistent reductions to target often occur over 2–6 weeks as dosing is adjusted. Gout flare frequency typically improves over several months, once a stable, urate-lowering dose is maintained and crystal burden decreases. Visible tophi may shrink over months to years, depending on baseline size and the achieved urate level.

Compare With Alternatives

Febuxostat is another xanthine oxidase inhibitor used for chronic hyperuricemia. It may be considered when allopurinol is not tolerated or does not achieve targets. Monitoring guidance and cardiovascular considerations differ by patient profile.

Probenecid is a uricosuric agent that increases renal uric acid excretion. It can be useful in patients with good kidney function and low urinary stone risk. It is sometimes combined with a xanthine oxidase inhibitor when monotherapy is insufficient.

Certain diuretics can raise uric acid and complicate gout control. Thiazide-containing options such as Spironolactone Hctz or Hydrochlorothiazide may require individualized consideration.

Combination Therapy

• Flare prophylaxis: Low-dose colchicine or an NSAID is often used during initiation and dose changes to reduce flare risk.
• Urate-lowering combinations: A xanthine oxidase inhibitor can be combined with a uricosuric agent if needed to reach target urate.
• Stone prevention: Hydration and urine alkalinization (e.g., citrate) may be used for recurrent uric acid stones.
• Antimetabolites: Azathioprine or 6-mercaptopurine doses often require substantial reduction when coadministered.
• Anticoagulants and theophylline: Effects may increase; closer monitoring is often required.

Patient Suitability and Cost-Saving Tips

Allopurinol is used for gout prevention, chronic hyperuricemia, uric acid nephrolithiasis, and prevention of tumor lysis–related hyperuricemia with certain chemotherapies. It is generally not used for isolated asymptomatic hyperuricemia. Those with chronic kidney disease may start at lower doses with careful titration. See the Kidney Disease resource for related topics.

Allopurinol may not suit patients with a history of severe hypersensitivity to this drug. Risk of serious skin reactions is higher in HLA-B*58:01 carriers, particularly in certain Asian populations and those with kidney disease. Liver disease, significant drug interactions, and pregnancy or breastfeeding require individualized assessment.

Smart ways to save include choosing the generic, selecting multi-month supplies when appropriate, and aligning shipments to reduce repeat delivery fees. Reorder reminders can help maintain consistent therapy and avoid urgent local purchases. CanadianInsulin offers prompt, reliable service for prescription fulfillment and shipment.

Authoritative Sources

Allopurinol drug labeling on DailyMed

Health Canada Drug Product Database: Allopurinol

How Kerendia Uses Boost Heart And Kidney Health

Order Allopurinol from CanadianInsulin: add to cart, upload your prescription, and we ship with prompt, express, cold-chain handling.

This information is educational and not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified provider with questions about medications, dosing, or side effects.