Allopurinol Shortage: What Providers and Prescribers Need to Know in 2026

Allopurinol remains the first-line urate-lowering therapy (ULT) in the 2020 American College of Rheumatology (ACR) Guideline for the Management of Gout. While no national shortage of oral allopurinol tablets exists as of early 2026, providers are increasingly fielding patient calls about pharmacy-level stock-outs, formulary restrictions, and cost barriers. This clinical update addresses the current supply landscape, patient counseling considerations, and evidence-based guidance for transitioning to alternative ULTs when clinically indicated.

Current Supply Status (2026)

Oral allopurinol (100 mg and 300 mg tablets) is not listed on the FDA Drug Shortage Database as of 2026. The 200 mg oral tablet is less commonly manufactured and stocked, and the IV formulation (Aloprim, 500 mg) has experienced intermittent supply disruptions historically and should be considered for advance ordering in inpatient and oncology settings.

Patients presenting to your office or calling your triage line about allopurinol unavailability are most commonly experiencing:

• Temporary pharmacy-level stock-outs (most common in independent pharmacies)
• Inability to find the 200 mg tablet specifically (consider substituting with 100 mg tablets)
• Insurance formulary restrictions on the brand (Zyloprim) — generic is broadly covered

Patient Counseling: Managing Therapy Gaps

When patients experience a gap in allopurinol therapy, the key clinical concern is precipitating a gout flare upon restarting. As uric acid levels shift during drug holidays and re-initiation, crystal mobilization can occur. Counsel patients that:

1. A short gap of a few days (while locating medication) is generally not clinically significant.
2. Gaps exceeding 2–4 weeks may require re-titration when therapy resumes, especially in patients with tophi or history of frequent flares.
3. Colchicine or NSAID prophylaxis should be considered when restarting after a significant gap — consistent with ACR guidance to use prophylaxis for at least 3–6 months after initiating or changing ULT dose.

HLA-B*5801 Testing: Who Should Be Screened?

The HLA-B*5801 allele is strongly associated with allopurinol-induced severe cutaneous adverse reactions (SCAR), including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Allele frequency varies significantly by ancestry:

• Han Chinese, Thai, Vietnamese: ~6–8% prevalence (high risk — ACR recommends screening)
• African American: ~4% prevalence (ACR recommends screening)
• European: ~1% prevalence (screening not universally recommended)
• Japanese: ~0.5% prevalence (screening not routinely recommended)

For patients with positive HLA-B*5801 testing or who experience a hypersensitivity reaction to allopurinol, febuxostat is the preferred alternative. Allopurinol desensitization protocols exist but are complex and should only be undertaken by experienced specialists.

When to Consider Therapeutic Alternatives

The ACR 2020 Gout Guidelines specify the following clinical scenarios for switching from allopurinol:

• Allopurinol intolerance or hypersensitivity: Febuxostat 40–80 mg daily is the preferred alternative.
• Inadequate uric acid control at maximum tolerated allopurinol dose: Consider switching to or adding a uricosuric agent (probenecid, if renal function is adequate). Avoid switching to febuxostat as the default per ACR, given its cardiovascular risk warning.
• Azathioprine/6-MP co-administration: Allopurinol dramatically increases azathioprine and 6-mercaptopurine levels by inhibiting xanthine oxidase metabolism. If ULT is needed in these patients, probenecid is a safer choice, as it does not inhibit XO.
• Refractory tophaceous gout: Pegloticase (Krystexxa) IV every 2 weeks is indicated when patients fail all oral ULTs. Requires rheumatology co-management and monitoring for infusion reactions and anti-drug antibody formation.

Dosing Considerations in Renal Impairment

Allopurinol and its active metabolite oxypurinol are renally cleared. Dose reduction is required in patients with CKD. The 2020 ACR Guidelines no longer recommend capping allopurinol at 300 mg in CKD patients — rather, start low (50–100 mg in CKD stage 3 or worse) and titrate slowly to achieve the uric acid target of ≤6 mg/dL. The risk of allopurinol hypersensitivity syndrome (AHS) is higher in CKD — starting at the lowest dose reduces this risk.

How medfinder Can Help Your Patients

When patients call reporting they can't find allopurinol at their pharmacy, the fastest resolution is often simply directing them to a pharmacy that has it in stock. medfinder for providers allows you to help patients locate their medication quickly — medfinder calls pharmacies near the patient and texts them results. This can often resolve the situation without requiring a therapeutic substitution or additional provider time.

Key Clinical Takeaways

• Oral allopurinol is not in national shortage in 2026 — most patient calls are about pharmacy-level stock-outs
• Screen Southeast Asian and African American patients for HLA-B*5801 before initiating allopurinol
• Titrate slowly in CKD — start 50 mg in CKD stage 3+, no arbitrary 300 mg ceiling
• After therapy gap, restart with prophylaxis; consider re-titrating in high-risk patients
• Febuxostat is preferred if switching for intolerance, but use caution in cardiovascular disease