Detailed Drug Information:

DRUG CLASS AND MECHANISM: Mesalamine is a derivative ofsalicylic acid and is thought to be the active component of sulfasalazine (Azulfidine), a combination of a sulfa drug and salicylic acid. Mesalamineworks as an antiinflammatory agent in treating ulcerative colitis andCrohn's disease. Its benefit is believed to be due to a topical effect onthe inflamed bowel. Following rectal administration of mesalamine (byenema or suppository), only 15% of a dose is absorbed. Following oraladministration, 28% of a dose is absorbed. Mesalamine was approved by theFDA in December 1987.

PREPARATIONS: sustained-action gelatin capsules (Pentasa)containing 250mg; enteric coated tablets containing 400mg; rectal enema(Rowasa) containing 4 grams per 60 mL enema; rectal suppositories (Rowasa)containing 500mg.

STORAGE: The tablets, capsules, and enemas should be kept atroom temperature, 15-30°C (59-86°F). The suppositories should bestored between 19-26°C (66-79°F).

PRESCRIBED FOR: Mesalamine is used for the treatment of mild tomoderately severe colitis. The suppositories are limited to use inproctitis, the enemas to distal colitis (colitis involving only the partof the colon close to the rectum) or proctitis.

DOSING: The enema is inserted rectally, generally once daily atbedtime. It should be retained for at least 8 hours. The bottle should beshaken well prior to use. The protective sheath must be removed. Manyphysicians recommend that the patient lie on his/her left side with thelower leg extended and the upper (right) leg flexed forward for balancefor ease of administration.

The suppositories are often given twice daily; each should be retainedfor 1 to 3 hours or longer.

The 400mg delayed release (enteric-coated) tablets (Asacol) aregenerally taken 3 times a day. The sustained-action capsules (Pentasa) aregenerally taken 4 times a day during the acute phase, in order to induceremission.

While the benefits of mesalamine can be seen within 3 to 21 days ofstarting therapy, it may take up to 3 to 6 weeks for the enemas andsuppositories, 6 weeks for the tablets, and 8 weeks for the capsules tohave maximum effect.

DRUG INTERACTIONS: There are no known drug interactions with anyof the mesalamine products.

PREGNANCY: There are no adequate studies of mesalamine inpregnant women; however, studies in animals suggest no important effectson the fetus. Therefore, mesalamine may be used in pregnancy if thephysician feels that it is necessary. It also should be noted that thereis no effect of mesalamine on sperm count as there is with sulfasalazine(Azulfidine).

NURSING MOTHERS: Mesalamine is excreted in small amounts in breast milk. No side effects have been reported in nursing infants whosemothers have taken mesalamine. Since the possibility of side effectsalways exists, physicians must weigh the potential risks of mesalamine onthe infant against the benefits for the mother.

SIDE EFFECTS: Mesalamine is usually well-tolerated. Adverse effects that have been reported in large studies include: headache, abdominal pain, diarrhea,nausea, and dizziness. None of these effects,however, were reported more frequently with mesalamine than with placebo.Infrequently, patients may be intolerant of mesalamine, experiencingcramping, abdominal pain, bloody diarrhea, and sometimes fever or rash. Insuch cases, the medication is stopped. Mesalamine enemas contain sulfitesand should be avoided in persons who are sensitive to sulfites.