Allopurinol
Prescription ·Exploratory record · not publication-reviewed ·Updated July 13, 2026
A xanthine oxidase inhibitor used as first-line urate-lowering therapy for the chronic management of gout and hyperuricemia. Allopurinol reduces serum uric acid levels by inhibiting the enzyme that converts hypoxanthine and xanthine to uric acid, preventing the formation and deposition of monosodium urate crystals in joints and tissues.
Exploratory record, not a reviewed medical publication.
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This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.
What the research says.
A quick, data-only summary. The full evidence, dosing, and sources are below.
A xanthine oxidase inhibitor used as first-line urate-lowering therapy for the chronic management of gout and hyperuricemia. NutriStack rates the supporting evidence as strong. Common adult dosing is Start 100 mg daily, titrate by 100 mg every 2–4 weeks to target serum uric acid <6 mg/dL; typical range 200–600 mg daily (max 800 mg/day) (as prescribed by your physician), though a prescriber sets the actual dose. This profile indexes 10 sources.
The bottom line
Evidence rating strong. Most-documented uses: reduction of serum uric acid levels, prevention of recurrent gout flares, prevention and dissolution of uric acid kidney stones. 10 sources indexed (2016–2025), with 0 interaction records on file.
How it works, mechanistically.
Core mechanism
Inhibits xanthine oxidase, the enzyme responsible for the conversion of hypoxanthine to xanthine and xanthine to uric acid. By blocking this final step in purine catabolism, allopurinol and its active metabolite oxypurinol reduce serum uric acid production. This lowers the total body urate pool and prevents new crystal deposition.
Dosing & protocol.
Take after meals to reduce GI side effects; maintain adequate fluid intake to prevent xanthine stone formation2,7
Full safety detail.
Side effects
- Skin rash (discontinue if occurs)
- Gout flare during initiation (use prophylaxis)
- Elevated liver enzymes
- Nausea and diarrhea
- Hypersensitivity syndrome (rare but potentially fatal: fever, rash, eosinophilia, hepatitis, renal failure)
- Stevens-Johnson syndrome / toxic epidermal necrolysis (rare)
Contraindications
- Known hypersensitivity to allopurinol7,1
- HLA-B*5801 positive patients (strongly associated with severe cutaneous adverse reactions, screen in high-risk populations)
- Concurrent use with azathioprine or mercaptopurine (unless dose is significantly reduced)
- Caution in renal impairment (dose adjustment required)1,2
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Meta-analyses & systematic reviews
5- 1Comparative efficacy and safety of febuxostat and allopurinol in chronic kidney disease stage 3-5 patients with asymptomatic hyperuricemia: a network meta-analysisPMIDChen J, Zhang Y, Wang Y et al. · Renal failure · 2025
Chen J, Zhang Y, Wang Y et al.. Comparative efficacy and safety of febuxostat and allopurinol in chronic kidney disease stage 3-5 patients with asymptomatic hyperuricemia: a network meta-analysis. Renal failure. 2025
- 2The efficacy and safety of different doses of febuxostat and allopurinol: A meta-analysisPMIDZhang F, Wang Y · Joint diseases and related surgery · 2025
Zhang F, Wang Y. The efficacy and safety of different doses of febuxostat and allopurinol: A meta-analysis. Joint diseases and related surgery. 2025
- 3Allopurinol and endothelial function: A systematic review with meta-analysis of randomized controlled trialsPMIDAlem MM · Cardiovascular therapeutics · 2018
Alem MM. Allopurinol and endothelial function: A systematic review with meta-analysis of randomized controlled trials. Cardiovascular therapeutics. 2018
- 4Allopurinol augmentation in acute mania: A meta-analysis of placebo-controlled trialsPMIDChen AT, Malmstrom T, Nasrallah HA · Journal of affective disorders · 2018
Chen AT, Malmstrom T, Nasrallah HA. Allopurinol augmentation in acute mania: A meta-analysis of placebo-controlled trials. Journal of affective disorders. 2018
- 5Effects of Allopurinol on Arterial Stiffness: A Meta-Analysis of Randomized Controlled TrialsPMIDDeng G, Qiu Z, Li D et al. · Medical science monitor : international medical journal of experimental and clinical research · 2016
Deng G, Qiu Z, Li D et al.. Effects of Allopurinol on Arterial Stiffness: A Meta-Analysis of Randomized Controlled Trials. Medical science monitor : international medical journal of experimental and clinical research. 2016
Reference material
5- 6FitzGerald JD et al. 2020 American College of Rheumatology Guideline for Management of Gout. Arthritis Care Res. 2020.Source linkedPMID
- 7Stamp LK et al. Starting dose is a risk factor for allopurinol hypersensitivity syndrome: a proposed safe starting dose of allopurinol. Arthritis Rheum. 2012.Source linkedPMID
- 8Hershfield MS et al. Clinical pharmacogenetics implementation consortium guidelines for human leukocyte antigen-B genotype and allopurinol dosing. Clin Pharmacol Ther. 2013.Source linkedPMID
- 9Helget LN, Davis-Karim A, O'Dell JR et al.. Efficacy and Safety of Allopurinol and Febuxostat in Patients With Gout and CKD: Subgroup Analysis of the STOP Gout Trial. American journal of kidney diseases : the official journal of the National Kidney Foundation. 2024Source linkedPMID
- 10Mackenzie IS, Ford I, Nuki G et al.. Long-term cardiovascular safety of febuxostat compared with allopurinol in patients with gout (FAST): a multicentre, prospective, randomised, open-label, non-inferiority trial. Lancet (London, England). 2020Source linkedPMID
Common questions.
Quick answers about Allopurinol, drawn from the data on this page.
What is Allopurinol?
A xanthine oxidase inhibitor used as first-line urate-lowering therapy for the chronic management of gout and hyperuricemia. Allopurinol reduces serum uric acid levels by inhibiting the enzyme that converts hypoxanthine and xanthine to uric acid, preventing the formation and deposition of monosodium urate crystals in joints and tissues.
What is Allopurinol used for?
Commonly cited benefits of Allopurinol include: Reduction of serum uric acid levels; Prevention of recurrent gout flares; Prevention and dissolution of uric acid kidney stones; Treatment of hyperuricemia secondary to tumor lysis syndrome; Reduction of tophaceous deposits. NutriStack rates the overall evidence as strong.
What is a typical dose of Allopurinol?
A typical adult dose of Allopurinol is Start 100 mg daily, titrate by 100 mg every 2–4 weeks to target serum uric acid <6 mg/dL; typical range 200–600 mg daily (max 800 mg/day) (as prescribed by your physician). The commonly recommended form is Tablet. These are general ranges, not personalized advice; confirm the right dose with a clinician.
What are the side effects of Allopurinol?
Reported side effects include skin rash (discontinue if occurs), gout flare during initiation (use prophylaxis), elevated liver enzymes, nausea and diarrhea, hypersensitivity syndrome (rare but potentially fatal: fever, rash, eosinophilia, hepatitis, renal failure), stevens-johnson syndrome / toxic epidermal necrolysis (rare). This is educational information; check with a healthcare professional before use.
How strong is the evidence for Allopurinol?
NutriStack rates this as Strong, meaning multiple high-quality meta-analyses or systematic reviews converge on the same finding. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
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