Allergic reaction to allopurinol with cross-reactivity to oxypurinol

Ann Intern Med. 1976 Sep;85(3):333-5. doi: 10.7326/0003-4819-85-3-333.


A 25-year-old white man with gout and nephropathy and with a previous reaction to allopurinol was given a trial dose of oxypurinol. He developed malaise, a generalized erythematous reaction with edema, pruritus, and emesis; this was clinically identical to the reaction he experienced with allopurinol. When the patient's lymphocytes were exposed in vitro to oxypurinol and allopurinol, increased DNA synthesis was observed, suggesting an immunologic basis for the reaction. This patient indicates that clinical cross reactivity to allopurinol and oxypurinol does occur and may be of an immunologic basis. There is a need for additional xanthine oxidase inhibitors for such patients.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Allopurinol / adverse effects
  • Allopurinol / immunology*
  • Allopurinol / therapeutic use
  • Cross Reactions*
  • Drug Eruptions / immunology
  • Drug Hypersensitivity / immunology*
  • Gout / drug therapy
  • Humans
  • Lymphocyte Activation
  • Male
  • Oxypurinol / adverse effects
  • Oxypurinol / immunology*
  • Oxypurinol / therapeutic use
  • Pyrimidines / immunology*
  • Skin Tests


  • Pyrimidines
  • Allopurinol
  • Oxypurinol