It's not a "mesalamine" when it goes in, but once it hits the colon, the mesalamine is released.
It is in the family of 5-ASA, however, but a different delivery and how it's released can allow some patients to do better on it. It doesn't target the left-side, it's been noted that patients with left-sided UC seem to do well on it. Again, could be the delivery that allows it to make its way down by being distributed through the colon.
The same is with Osalazine (Dipentum).. Same with Sulfasalazine.
So, in reality, the three above aren't considered mesalamine medication until it's released. Asacol, Lialda, etc that are pure mesalamine are released into the colon the same way they go in....their release happens once the outer coating is broken. Not that they have to be separated from ANOTHER medication that they're bound to in order to make it into the colon.
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