Allopurinol

Metabolicprescriptionoral · inferred

Xanthine oxidase inhibitor first-line for gout urate-lowering therapy and tumor lysis prophylaxis. Parent drug rapidly converted to the active, long-lived metabolite oxypurinol (t1/2 18-30 h), which drives sustained urate lowering. Increasing interest in cardiovascular and longevity applications via reduced oxidative stress. Typical dose 100-600 mg/day titrated to serum urate target.

Projected serum levels — 300 mg, once daily

Allopurinol
Allopurinol modeled serum levels, 300 mg once daily over 15 days Population-based pharmacokinetic estimate. Steady state reached after approximately 1 days. 0 50 100 150 200 Day 0 Day 4 Day 8 Day 11 Day 15 Time on a regular schedule ≈ steady state · day 1

Maintenance schedule: 300 mg once daily (oral).

Modeled steady state after ~1 days: peak ≈ 178 mg, trough ≈ 2.0 mg body load. Population-based estimate over 15 days for a 300 mg dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.

Key facts

Category
Metabolic
Route modeled
Oral
Model confidence
inferred
Half-life
1.5 h
Common dose
300 mg
Suggested maximum
800 mg/day
Reference dose range
150–800 mg (single dose)
Suggested cadence
once daily
Validated against
300 mg oral — Cmax 2.6 mg/L at 1.5 h

Documented interactions

  • moderate
    Azathioprine (Imuran) + Allopurinol CYP inhibition

    Allopurinol mechanism_based of xanthine_oxidase predicted to change Azathioprine (Imuran) AUC by ~1.68x

  • moderate
    Pyrazinamide (PZA) + Allopurinol CYP inhibition

    Allopurinol mechanism_based of xanthine_oxidase predicted to change Pyrazinamide (PZA) AUC by ~1.82x

Serum checks 2 modeled interaction pairings for allopurinol across your whole stack — absorption conflicts, enzyme inhibition, and nutrient depletion included.

Research behind this entry

  1. 2012 American College of Rheumatology guidelines for management of gout. Part 1: Systematic nonpharmacologic and pharmacologic therapeutic approaches to hyperuricemia Khanna D et al. · Arthritis Care & Research, 2012 DOI

    ACR gout guideline establishing allopurinol as first-line urate-lowering therapy with titration to serum urate target <6 mg/dL, including HLA-B*5801 testing in high-risk populations.

  2. Allopurinol use and risk of fatal cardiovascular disease: a propensity score-matched analysis Beattie CJ et al. · American Journal of Medicine, 2014 DOI

    Propensity-matched cohort study showed allopurinol use was associated with reduced fatal cardiovascular events in gout patients, supporting broader CV interest beyond urate lowering.

  3. Clinical pharmacokinetics of allopurinol and oxypurinol Day RO et al. · Clinical Pharmacokinetics, 2007 DOI

    PK review characterizing allopurinol's ~90% oral bioavailability, 1-2 hour parent half-life, rapid conversion to oxypurinol (active metabolite with 18-30 hour half-life), and renal elimination of oxypurinol.

3 published studies referenced in the app, each with a plain-language summary.