This monograph refers to 4-aminosalicylic acid/para-aminosalicylic acid (PAS). 4-aminosalicylic acid is metabolized by acetylation. No data indicates that 4-aminosalicylic acid interact with CYP enzymes, which may indicate that it is not an inducer or an inhibitor of them. Risk for gastrointestinal adverse events in the form of anorexia, nausea, vomiting and diarrhoea motivates vigilance against insufficient intake of food, especially of carbohydrate.

It is also known as aminosalyl.

Aminosalicylic acid is indicated in the treatment of tuberculosis. Common side effects that can be potentially porphyrinogenic through reduction in carbohydrate intake and that also can be confused with an acute porphyria attack are anorexia, nausea, vomiting and diarrhoea.

4-aminosalicylic acid is metabolized in the intestine and liver mainly by acetylation. 50% or more of the dose is excreted as the acetylated metabolites. When given orally it is readily absorbed. The half-life elimination is about 1 hour (Martindale). No data indicates that 4-aminosalicylic acid interact with CYP enzymes, which may indicate that it is not an inducer or an inhibitor of them.