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Aminosalicylic acid Side Effects

In Summary

More frequently reported side effects include: eosinophilia and leukocytosis. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to aminosalicylic acid: oral tablet

Along with its needed effects, aminosalicylic acid may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking aminosalicylic acid:

More common

  • Fever
  • joint pains
  • skin rash or itching
  • unusual tiredness or weakness

Less common

Check with your doctor as soon as possible if any of the following side effects occur while taking aminosalicylic acid:

Less common

- with long-term, high-dose therapy
  • Changes in menstrual periods
  • decreased sexual ability in males
  • dry, puffy skin
  • swelling of front part of neck
  • weight gain (unusual)

Some side effects of aminosalicylic acid may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

For Healthcare Professionals

Applies to aminosalicylic acid: compounding powder, oral granule enteric coated


Gastrointestinal side effects have been reported the most frequently. These have included nausea, vomiting, and abdominal pain.[Ref]

The incidence of gastrointestinal side effects is reduced with lower doses (8 g daily) and with the granular formulation of the drug.[Ref]


Hypersensitivity side effects have been reported rarely. The first signs have included rash, often followed by fever, and much less frequently, anorexia, nausea or diarrhea. The drug has been restarted in small but gradually increasing doses under a closely followed desensitization protocol.[Ref]


Patients should be closely monitored during the first three months of therapy and treatment must be discontinued immediately at the first signs of rash, fever, jaundice, or other sign of intolerance.[Ref]

Hepatic side effects have included jaundice and hepatitis. In patients diagnosed with hepatitis, hepatomegaly was invariably present with lymphadenopathy (45%), leukocytosis (79%), and eosinophilia (55%). Prompt recognition of symptoms with discontinuation of therapy led to recovery. Failure to recognize symptoms of liver injury can result in a mortality of up to 21%.[Ref]


A reduction in thyroxine synthesis has been associated with the administration of the sodium salt of aminosalicylic acid. The development of goiter can be prevented by the administration of thyroxine but not iodide.[Ref]

Endocrine side effects have included hypothyroidism, especially with prolonged administration. It may be accompanied by goiter development.[Ref]


Hematologic side effects have included leukopenia, agranulocytosis, thrombocytopenia, Coombs' positive hemolytic anemia, and reduction in prothrombin.[Ref]


1. "Product Information. Paser Granules (aminosalicylic acid)." Jacobus Pharmaceutical Company, Princeton, NJ.

2. American Thoracic Society, CDC, Infectious Diseases Society of America "Treatment of tuberculosis." MMWR Morb Mortal Wkly Rep 53 (2005): 1203

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.