Mesalamine is no better than placebo in preventing recurrent diverticulitis, and is not recommended for its treatment, researchers conclude from 2 international phase 3 studies. The findings are published in the October issue of Gastroenterology.
Diverticular disease is characterized by formation of small pouches (diverticula) that push outward through weak spots in the colon wall. Diverticulitis occurs when the diverticula become inflamed, or irritated and swollen, and infected.
Mild acute diverticulitis is treated with broad-spectrum oral antibiotics, but more severe diverticulitis can require hospitalization, intravenous antibiotics, bowel rest, percutaneous drainage, or surgery. Diverticulitis recurs in many patients, so a pharmacologic treatment would be valuable.
Jeffrey B. Raskin et al. evaluated the efficacy and safety of multimatrix mesalamine, compared with placebo, in preventing recurrent diverticulitis in 2 large clinical trials. In the studies, 590 (PREVENT1) and 592 (PREVENT2) adult patients with 1 or more cases of acute diverticulitis in the previous 24 months that resolved without surgery received mesalamine (1.2 g, 2.4 g, or 4.8 g) or placebo once daily for 104 weeks.
Raskin et al. found that mesalamine did not reduce the rate of diverticulitis recurrence at week 104. In PREVENT1, 53%−63% did not have disease recurrence, compared with 65% of those given placebo. In PREVENT2, 59%−69% of patients did not have disease recurrence, compared with 68% of those given placebo.
Mesalamine did not reduce time to recurrence, and similar proportions of patients in all groups required surgery. No new adverse events were associated with mesalamine administration.
Raskin et al. conclude that it is clear that mesalamine does not prevent diverticulitis recurrence or improve health-related quality of life in patients with the disease.
Mesalamine (also known as or 5-aminosalicylic acid or 5-ASA) is thought to reduce inflammation through multiple mechanisms, including blocking prostaglandin production and activating the peroxisome proliferator-activated receptor-g. However, its affect on these processes does not appear to prevent recurrence of diverticulitis. The authors propose investigating alternative options, such as high-fiber diets (or fiber supplements) in patients with diverticular disease.
The authors found no correlation between body mass and diverticulitis recurrence, and no meaningful trends in subgroup analyses. Although the prevalence of diverticular disease is high in the United States, Europe, and Australia, it is much lower in urbanized areas of Asia and is almost unknown in rural Africa or Asia.