Aminosalicylic acid Disease Interactions

The use of aminosalicylic acid is contraindicated in patients with severe renal impairment. Both aminosalicylic acid and its acetyl metabolite are primarily eliminated by the kidney, and the latter tends to accumulate extensively in patients with renal failure. Some accumulation may also occur in patients with lesser degrees of renal dysfunction. Caution is advised when aminosalicylic acid is used in these patients.

Aminosalicylic acid is decarboxylated in stomach acid to an inactive metabolite that is hepatotoxic. In a retrospective study of nearly 7,500 patients treated with older formulations of the drug, hepatitis developed in 0.5% of them. Premonitory symptoms (most often rash, followed by fever and, much less frequently, by GI disturbances such as anorexia, diarrhea, or nausea) usually occurred within the first 3 months of therapy and preceded jaundice by a few days to several weeks. Although the currently marketed granule formulation of aminosalicylic acid contains an acid- resistant coating that protects against degradation in the stomach, the drug should nevertheless be used with caution in patients with liver disease. These patients should be followed particularly closely for the first three months, and therapy promptly discontinued if liver disease becomes worse or premonitory symptoms appear. The drug should be administered sprinkled in an acidic food (e.g., apple sauce, yogurt) or suspended in a fruit juice to prevent dissolution of the coating, which occurs under neutral conditions.