Allopurinol Stevens-Johnson Syndrome | Latest Updates

Allopurinol, a gout drug sold as Zyloprim and in generic form, has been associated with Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). These severe skin reactions cause blistering and can sometimes be fatal. The FDA-approved label warns of these reactions. It says they occur in approximately 5 in 10,000 patients taking allopurinol. It also names the HLA-B*58:01 gene as a risk marker. No class action or MDL has been filed over allopurinol and SJS, so any claim would be an individual one. The label says the risk is mostly in the first few months of therapy.

Latest Allopurinol Stevens-Johnson Syndrome Lawsuit Updates

November 10, 2025: RheumNow Reports on HLA Gene Study

RheumNow reported on a JAMA Dermatology study. It was a matched cohort study of people taking allopurinol. The study found HLA-B*58:01 and a second gene variant strongly associated with severe skin reactions to the drug [1]. The report calls them strong but incomplete indicators of risk. The findings show a link. They are not proof of cause in any one patient.

October 29, 2025: Vanderbilt Announces HLA-A*34:02 Study

Vanderbilt University Medical Center announced a JAMA Dermatology study. It found that HLA-A*34:02, tested with HLA-B*58:01, could explain risk in over 80% of U.S. patients [2]. The release says HLA-B*58:01 alone misses more than one-third of at-risk patients in the U.S. and up to 45% of Black individuals.

October 2, 2023: Case Report Describes Allopurinol-Induced SJS

Clinical Pharmacology published a case report of allopurinol-induced SJS in a 95-year-old woman with stage IV chronic kidney disease [3]. Her rash began 10 days after she started 100 mg daily. The authors, Anis and Meher, called the reaction fatal.

July 18, 2022: Vietnam Study on Allopurinol SJS and TEN Published

The Journal of Clinical Pharmacy and Therapeutics first published an analysis of Vietnam’s national pharmacovigilance database on allopurinol-induced SJS/TEN [4]. The authors studied spontaneous adverse drug reaction reports. These went to the Vietnam National Drug Information and Adverse Drug Reaction Monitoring Centre between 2010 and 2019.

What Is Allopurinol Stevens-Johnson Syndrome?

The label from the FDA says allopurinol tablets are a xanthine oxidase inhibitor. They are used for gout, high uric acid from cancer therapy and recurrent calcium oxalate stones [5]. The label also warns of serious and sometimes fatal skin reactions in people taking it, including Stevens-Johnson syndrome and toxic epidermal necrolysis.

Who May Be Affected?

People who take allopurinol and then develop a skin rash, blisters, SJS or TEN may be affected. People who develop drug reaction with eosinophilia and systemic symptoms (DRESS) after taking allopurinol may also be affected. The label says the HLA-B*58:01 gene variant is more common in people of African, Asian and Native Hawaiian or Pacific Islander ancestry. Carriers have a higher risk. The label names four drugs that may raise the risk of serious skin reactions. They are bendamustine, thiazide diuretics, ampicillin and amoxicillin. Our Stevens-Johnson Syndrome Lawsuit page covers the wider condition. Whether you have a claim depends on your own facts, and only a legal review of them can say.

Reported Injuries or Damages

The label lists SJS, TEN and DRESS in people taking allopurinol. It also lists exfoliative, urticarial and purpuric lesions. It lists generalized vasculitis and irreversible hepatotoxicity too. In the Vietnam study, 392 of 72,822 reports were SJS/TEN. Of those, 65 cases (16.6%) involved allopurinol. The authors found 61.6% of SJS/TEN cases were avoidable. They linked this to inappropriate prescribing. The JAMA Dermatology study matched 16 patients with specialist-adjudicated reactions to 160 allopurinol-tolerant individuals. HLA-B*58:01 (OR 28.0) and HLA-A*34:02 (OR 20.6) were each linked to higher risk. The Vanderbilt release says SJS/TEN and DRESS have mortality rates for allopurinol of 20-30% and approximately 9%. The case report described a desquamating rash with oral, ocular and genital involvement. It also described MRSA bacteremia and acute kidney injury needing hemodialysis. These are label statements and medical reports. They are not lawsuit findings.

Evidence to Preserve

Keep the following records and items, because they may help show what happened and when:

• Prescription and pharmacy records showing the drug, strength, manufacturer and fill dates
• The pill bottle and its label
• Medical, emergency-room, burn-unit and hospital records
• Photographs of the rash, blisters and any scarring
• Any HLA genetic test result
• A list of other medicines taken at the same time
• Notes on your symptoms and the dates they began

Filing Deadlines

Filing deadlines come from state law. They vary with where you live and when the reaction, the diagnosis or the discovery of its cause happened. Even strong facts cannot save a claim that is filed too late. A lawyer can tell you which deadline applies to your situation, so ask one promptly.

Frequently Asked Questions

When Should Allopurinol Be Discontinued?

Allopurinol should be discontinued immediately if a skin rash develops, the label says. Patients are told to stop it permanently at the first sign of a rash or other hypersensitivity and to seek medical attention promptly.

What Organs Is Allopurinol Hard On?

Allopurinol is hard on the kidneys and the liver, according to the label. It lists nephrotoxicity, which may cause acute kidney injury. People with kidney disease need lower doses. It also lists hepatotoxicity, with reversible cases reported.

Is There a Lawsuit over Allopurinol Stevens-Johnson Syndrome?

A lawsuit over allopurinol Stevens-Johnson syndrome has so far meant individual suits. Alexander v. Northstar Rx LLC (W.D. La. 1:11-cv-00571) was a single-plaintiff product-liability case over generic allopurinol, filed April 11, 2011 and terminated October 19, 2011.

What Does the Research Say About Allopurinol Skin Reactions?

The research on allopurinol skin reactions includes a Vanderbilt study led by Elizabeth Phillips, MD. A 2023 case report also describes a woman treated with IV methylprednisolone for 3 days, then a steroid taper. Her skin lesions resolved after 1 month in hospital.

Who Is at Higher Risk of Allopurinol Skin Reactions?

The higher risk of allopurinol skin reactions applies to carriers of HLA-B*58:01. The label puts the allele frequency at about 8 to 10% in Han Chinese people. It is about 4% in Black people and under 1% in people of European descent.

Should Patients Get an HLA-B*58:01 Test Before Taking Allopurinol?

The label says patients may consider HLA-B*58:01 screening before allopurinol where the allele is known to be common. It does not recommend use in HLA-B*58:01 positive patients. The exception is when the benefits clearly outweigh the risks.

References

1. https://rheumnow.com/news/genetic-risks-and-severe-cutaneous-reactions-allopurinol
2. https://www.newswise.com/articles/new-genetic-marker-found-to-predict-severe-gout-drug-reactions-in-us-patients
3. https://pmc.ncbi.nlm.nih.gov/articles/PMC10557962/
4. https://pubmed.ncbi.nlm.nih.gov/35848069/
5. https://dailymed.nlm.nih.gov/dailymed/services/v2/spls/71fd88d2-cfd8-4abd-bb15-7ef2699ccf9d.xml