Lack of cross-reactivity between 5-aminosalicylic acid-based drugs: a case report and review of the literature.

BACKGROUND: 5-Aminosalicylic acid (5-ASA)-containing drugs are the mainstay of therapy in inflammatory bowel disease, but adverse reactions to these medications are relatively common. Because there may be a lack of cross-reactivity among the various 5-ASA formulations, treatment with alternative preparations is sometimes possible even after an apparent allergic reaction to a 5-ASA product. OBJECTIVE: To describe a patient with a possible allergy to 2 different 5-ASA drugs who tolerated a third. METHODS: A 27-year-old man with Crohn disease developed a rash while taking mesalamine (Pentasa and Asacol). Treatment with 5-ASA products was discontinued, and 6-mercaptopurine and prednisone were prescribed. He then experienced multiorgan failure secondary to herpes simplex infection, which required discontinuation of the immunosuppressive therapy. After recovery from the acute infection, he underwent successful graded challenge with balsalazide. RESULTS: The patient continued treatment with balsalazide for 9 months, with good control of his inflammatory bowel disease and no adverse effects. CONCLUSIONS: Adverse reactions to 1 or more 5-ASA medications do not necessarily preclude the use of others in the same class. A treatment algorithm for patients with adverse reactions to 5-ASA is outlined based on the case report and review of the literature.

Acute pancreatitis secondary to 5-aminosalicylic acid therapy in a patient with ulcerative colitis.

Therapy with oral 5-aminosalicylic acid (5-ASA) for ulcerative colitis has been reported to be effective and safe. We describe a case of biochemically proven mild acute pancreatitis occurring after 9 d of oral 5-ASA therapy for ulcerative colitis. A hypersensitivity mechanism seemed to be involved in the development of pancreatitis probably owing to erratic systemic absorption of the drug. We suggest clinical and biochemical monitoring for early diagnosis of pancreatitis in patients with ulcerative colitis receiving 5-ASA administration. This is the first report of acute pancreatitis developed by oral 5-ASA therapy for the treatment of ulcerative colitis in the literature of Japan.

Oral desensitization to 5-aminosalicylic acid medications.

BACKGROUND: Although hypersensitive subjects have been desensitized to oral sulfasalazine, the feasibility of oral desensitization to the drug's active moiety, 5-aminosalicylic acid has been questioned and never been reported. METHODS: We devised a 5-aminosalicylic acid desensitization protocol and administered the drug to two hypersensitive subjects on three occasions. RESULTS: Both 5-aminosalicylic acid hypersensitive subjects were successfully desensitized without complications and were able to tolerate therapeutic doses. CONCLUSION: Despite changing the drug's properties by crushing it for incrementally increasing administration, we successfully desensitized two patients on three occasions with 5-aminosalicylic acid.