The mechanism of action of mesalamine (and sulfasalazine) is unknown, but it appears to be topical rather than systemic. Mucosal production of arachidonic acid (AA) metabolites, both through the cyclooxygenase pathways, i.e., prostanoids, and through the lipoxygenase pathways, i.e., leukotrienes (LTs) and hydroxyeicosatetraenoic acids (HETEs), is increased in patients with chronic inflammatory bowel disease, and it is possible that mesalamine diminishes inflammation by blocking cyclooxygenase and inhibiting prostaglandin (PG) production in the colon.

PENTASA is indicated for the induction of remission and for the treatment of patients with mildly to moderately active ulcerative colitis.

The recommended dosage for the induction of remission and the symptomatic treatment of mildly to moderately active ulcerative colitis is 1 g (4 PENTASA 250-mg capsules or 2 PENTASA 500-mg capsules) 4 times a day for a total daily dosage of 4 g. Treatment duration in controlled trials was up to 8 weeks. PENTASA capsules may be swallowed whole, or alternatively, the capsule may be opened and the entire contents sprinkled onto applesauce or yogurt. The entire contents should be consumed immediately. The capsules and capsule contents must not be crushed or chewed. Safety and efficacy of PENTASA in pediatric patients have not been established.

In combined domestic and foreign clinical trials, more than 2100 patients with ulcerative colitis or Crohn’s disease received PENTASA therapy. Generally, PENTASA therapy was well tolerated. The most common events (i.e., greater than or equal to 1%) were diarrhea (3.4%), headache (2.0%), nausea (1.8%), abdominal pain (1.7%), dyspepsia (1.6%), vomiting (1.5%), and rash (1.0%). See package insert for complete information.

PENTASA is contraindicated in patients who have demonstrated hypersensitivity to mesalamine, any other components of this medication, or salicylates.

Caution should be exercised if PENTASA is administered to patients with impaired hepatic function. Mesalamine has been associated with an acute intolerance syndrome that may be difficult to distinguish from a flare of inflammatory bowel disease. Although the exact frequency of occurrence cannot be ascertained, it has occurred in 3% of patients in controlled clinical trials of mesalamine or sulfasalazine. See package insert for complete information.