mesalazine

mesalazine /me·sal·a·zine/ (mĕ-sal´ah-zēn) mesalamine.

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mesalazine, mesalamine

5-aminosalicylic acid; the active anti-inflammatory component of sulfasalazine when used in the treatment of inflammatory bowel disease. Used orally or rectally as suppositories or enemas.

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mesalamine (5-aminosalicylic acid, 5-ASA, mesalazine, mesalazine)

Asacol, Canasa, Ipocol (UK), Lialda, Mesasal (CA), Mesren (UK), Pentasa, Rowasa, Salofalk (CA) (UK)

Pharmacologic class: 5-amino-2-hydroxybenzoic acid

Therapeutic class: GI anti-inflammatory drug

Pregnancy risk category B

Action

Unknown. Thought to act in colon, where it blocks cyclooxygenase and inhibits prostaglandin synthesis.

Availability

Capsules (extended-release): 250 mg, 500 mg

Rectal suspension: 4 g/60 ml

Suppositories: 500 mg, 1,000 mg

Tablets (delayed-release): 400 mg (Pentasa), 1.2 g (Lialda)

⊘Indications and dosages

➣ Active ulcerative colitis

Adults: 800 mg P.O. (Asacol delayed-release tablets) t.i.d. for 6 weeks

➣ To induce remission in mildly to moderately active ulcerative colitis

Adults: 1 g P.O. (Pentasa extended-release capsules) q.i.d. for a total dosage of 4 g daily for up to 8 weeks. Or, two to four 1.2 g (Lialda) extended-release tablets P.O. once daily for total daily dose of 2.4 or 4.8 g for up to 8 weeks.

➣ Active distal ulcerative colitis, proctosigmoiditis, or proctitis

Adults: 4-g enema (Rowasa 60 ml) P.R. daily at bedtime, retained for 8 hours. Continue for 3 to 6 weeks.

➣ Active ulcerative proctitis

Adults: 500 mg (Canasa suppository) P.R. b.i.d., increased to t.i.d. if response inadequate after 2 weeks. Or 1,000 mg (suppository) P.R. at bedtime, continued for 3 to 6 weeks.

➣ To maintain remission of ulcerative colitis

Adults: 1.6 g (Asacol) P.O. daily in divided doses

Contraindications

• Hypersensitivity to drug, its components, or salicylates

Precautions

Use cautiously in:
• severe hepatic or renal impairment
• allergy to sulfasalazine
• pyloric stenosis (delayed-release tablets)
• conditions predisposing to development of myocarditis or pericarditis
• pregnant or breastfeeding patients
• children younger than age 18 (safety and efficacy not established).

Administration

• Give Lialda tablets with meal.
• Make sure patient swallows tablets whole without crushing or chewing.
• For best effect, have patient retain suppository for 1 to 3 hours.

Route	Onset	Peak	Duration
P.O.	Unknown	Unknown	6-8 hr
P.R.	Unknown	Unknown	24 hr

Adverse reactions

CNS: headache, dizziness, malaise, weakness

CV: chest pain, mesalamine-induced cardiac hypersensitivity reactions (myocarditis and pericarditis)

EENT: rhinitis, pharyngitis

GI: nausea, vomiting, diarrhea, eructation, flatulence, anal irritation (with rectal use), pancreatitis

GU: interstitial nephritis, renal failure

Musculoskeletal: back pain

Skin: alopecia, rash

Other: fever, acute intolerance syndrome, anaphylaxis, acute intolerance syndrome

Interactions

Drug-drug. Azathioprine, 6-mercaptopurine: increased potential for blood disorders

Nephrotoxic drugs (including nonsteroidal anti-inflammatory agents): increased risk of renal adverse reactions

Patient monitoring

☞ Monitor carefully for mesalamine-induced cardiac hypersensitivity reactions (myocarditis and pericarditis).
☞ Closely monitor patients with history of allergic reactions to sulfasalazine or sulfite sensitivity (if using enema).
• Assess kidney and liver function before and periodically during therapy.
• Monitor for suppository efficacy, which should appear in 3 to 21 days. However, know that treatment usually continues for 3 to 6 weeks.
☞ Watch for signs and symptoms of intolerance syndrome, such as cramping, acute abdominal pain, bloody diarrhea, fever, headache, and rash. If these occur, discontinue drug and notify prescriber.
☞ Watch for signs and symptoms of intolerance syndrome, such as cramping, acute abdominal pain, bloody diarrhea, fever, headache, and rash. If these occur, discontinue drug. Drug may be restarted later only if clearly needed, under close medical supervision and at reduced dosage.

Patient teaching

• Instruct patient to swallow tablets or capsules whole.
• Tell patient to contact prescriber if partially intact tablets repeatedly appear in stools.
• Advise patient using suppository to avoid excessive handling and to retain suppository for 1 to 3 hours or longer for maximum benefit.
• Teach patient about proper enema administration. Tell him to stay in position for at least 30 minutes and, if possible, retain medication overnight.
☞ Advise patient to immediately report breathing difficulties, allergic symptoms, cramping, acute abdominal pain, bloody diarrhea, fever, headache, or rash.
• As appropriate, review all other significant and life-threatening adverse reactions, especially those related to the drugs mentioned above.