Safety of 5-Aminosalicylic Acid Derivatives in Patients with Sensitivity to Acetylsalicylic Acid and Nonsteroidal Anti-inflammatory Drugs.

BACKGROUND One of the cornerstones of the management of inflammatory bowel disease is the use of 5-aminosalicylic acid (5-ASA) compounds for treatment of flares and as maintenance therapy during remission. There are concerns about using 5-ASA in patients with a history of hypersensitivity to acetylsalicylic acid (ASA). OBJECTIVE To assess the literature with respect to the safety of 5-ASA compounds in patients with documented sensitivity to ASA or nonsteroidal anti-inflammatory drugs (NSAIDs). DATA SOURCES A literature search was conducted in the MEDLINE and Embase databases, using various search terms, including "aminosalicylic acids", "non-steroidal anti-inflammatory agents," "hypersensitivity", and "allergy". The search was limited to articles (of any study design) published in English. Abstracts, full articles, and reference lists from retrieved articles were assessed to identify further relevant literature. STUDY SELECTION AND DATA EXTRACTION Of 485 citations identified in the initial search, 4 case reports were relevant to the study objective and were analyzed in detail. DATA SYNTHESIS Three of the case reports described the successful use of 5-ASA compounds in patients with prior sensitivity to ASA or an NSAID. The fourth report described a reaction to 5-ASA in a patient who had previously tolerated ASA. All of the reports were limited by lack of investigation into the validity of the reported sensitivity to ASA or 5-ASA. CONCLUSIONS There is a dearth of evidence demonstrating cross-reactivity between ASA or NSAID and 5-ASA. This lack of information may relate to the mechanism of action of 5-ASA. This agent controls inflammation by inhibiting prostaglandin E2 and leukotrienes. In contrast, ASA-induced or NSAID-induced reactions are due to inhibition of the cycloxygenase-1 enzyme and subsequent release of histamine and synthesis of leukotrienes. Further reports describing the safety of 5-ASA use in patients with sensitivity to ASA or NSAIDs are needed before safety in this situation can be definitively determined. In patients with sensitivity to ASA or NSAID who require 5-ASA, a test dose of 5-ASA (to rule out potential cross-reactivity) or further investigation of the ASA or NSAID sensitivity is recommended.