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U.S. Department of Health and Human Services


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Azulfidine (Sulfasalazine) Tablets, USP and Azulfidine EN-Tabs (Sulfasalazine Delayed Release) Tablets, USP

Detailed View: Safety Labeling Changes Approved By FDA Center for Drug Evaluation and Research (CDER)


March 2014

Summary View


  • Serious infections, including fatal sepsis and pneumonia, have been reported. Some infections were associated with agranulocytosis, neutropenia, or myelosuppression. Discontinue AZULFIDINE if a patient develops a serious infection. Closely monitor patients for the development of signs and symptoms of infection during and after treatment with AZULFIDINE. For a patient who develops a new infection during treatment with AZULFIDINE, perform a prompt and complete diagnostic workup for infection and myelosuppression. Caution should be exercised when considering the use of sulfasalazine in patients with a history of recurring or chronic infections or with underlying conditions or concomitant drugs which may predispose patients to infections.
  • Severe hypersensitivity reactions may include internal organ involvement, such as hepatitis, nephritis, myocarditis, mononucleosis-like syndrome (i.e., pseudomononucleosis), hematological abnormalities (including hematophagic histiocytosis), and/or pneumonitis including eosinophilic infiltration


Drug/Laboratory Test Interactions
  • Several reports of possible interference with measurements, by liquid chromatography, of urinary normetanephrine causing a false-positive test result have been observed in patients exposed to sulfasalazine or its metabolite, mesalamine/mesalazine.


Postmarketing Reports
  • Blood dyscrasias: pseudomononucleosis
  • Cardiac disorders: myocarditis
  • Metabolism and nutrition system disorders: folate deficiency
  • Renal and urinary disorders: nephrolithiasis
  • Respiratory, thoracic and mediastinal disorders: oropharyngeal pain


December 2012

Summary View


Nursing Mothers
  • There have been five reports with limited data of bloody stools or diarrhea in human milk fed infants of mothers taking sulfasalazine…