Gout medication, Zyloprim (allopurinol) has been associated with serious hypersensitivity reactions in some patients, according to a recent study.
Zyloprim, which was approved by the U.S. Food and Drug Administration (FDA) in 1966, for the treatment of gout, has led to some serious reactions in patients, according to an article published online in the October 2013 issue of Drug Safety. The review looked at hypersensitivity reactions associated with the drug. Allopurinol is prescribed off-label for a number of other uses, AdverseEvents reported.
Researchers reviewed literature on 901 patients from 320 studies or other published works, and found that most—78 percent—included in the study were of Asian descent, according to AdverseEvents. Also, most of the patients—802 in all—were categorized as having experienced Zyloprim hypersensitivity and about 90 percent of these people showed signs of hypersensitivity within 60 days of when treatment was initiated. There were 109 patient deaths; 94 indicated Zyloprim/allopurinol as the cause.
The researchers concluded that patients who take diuretics and patients who are diagnosed with a prior kidney impairment might be at increased risk for developing allopurinol sensitivity, according to AdverseEvents. The researchers also concluded that future research should be more clearly documented to better identify patients at risk for hypersensitivity reactions, AdverseEvents reported
Zyloprim is used to teat patients who exhibit symptoms of primary or secondary gout such as acute attacks, tophi, joint destruction, uric acid lithiasis, and/or nephropathy; management of patients with leukemia, lymphoma, and malignancies; and management of patients with recurrent calcium oxalate calculi. Zyloprim is manufactured by Prometheus Laboratories; generic formulations of allopurinol are marketed in the United States.
FDA Adverse Event Reporting System (FAERS) data from November 1, 1997 through December 31, 2012, was aggregated and standardized by the AdverseEvent RxFilter process, and revealed 38,740 serious adverse events in which Zyloprim, or its generic equivalent, were listed as a suspect drug. Of these, 1,505 reports listed Zyloprim, or its generic equivalent, as the primary suspect.
The most commonly reported side effects tied to Zyloprim, or its generic equivalent, were pyrexia (fever), Stevens-Johnson syndrome, and drug rash with eosinophilia and systemic symptoms. The team identified 835 hospitalizations and 232 patient deaths in which Zyloprim, or its generic equivalent, was indicated as the primary suspect.
SJS is a severe sensitivity reaction that causes:
- Blistering of the mucous membranes, which typically occurs in the mouth, eyes, and vagina, and can spread to internal organs
- Patchy areas of rash that eventually peel off the skin
The most severe cases of SJS are referred to as toxic epidermal necrolysis (TEN). When over 30 percent of the body is impacted, the condition becomes TEN. Both SJS and TEN typically call for hospital burn unit treatment.