5-ASA are also known as Aminosalicylic acids. They are chemically related to aspirin, and work by damping down the inflammatory process, so allowing damaged tissue to heal.
There are several types of 5-ASA drugs:
sulphasalazine (brand name Salazopyrin®)
mesalazine (Asacol®, Pentasa®, Salofalk® and Mezavant®). This 5-ASA comes in different formulations which target slightly different parts of the digestive system. Asacol and Salofalk tablets and granules have a special coating that dissolves at a certain pH (acidity) in the gut. This means that they work best in the last part of the small intestine and the beginning of the colon. Pentasa tablets and granules work throughout the gut. Mezavant tablets release their mesalazine as they pass through the large intestine (colon)
olsalazine (Dipentum®). This 5-ASAs also works best in the large intestine (colon)
There are also several topical forms of 5-ASA such as suppositories, foams, and enemas.
The scheme below demonstrates the areas of 5-ASA action depending on the form of the drug being used:
To find more information about 5-ASA, refer to the corresponding sections.