Makindo Medical Notes

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About Mesalazine

• Primarily used to treat inflammatory bowel diseases, including ulcerative colitis and Crohn’s disease.
• Part of the 5-aminosalicylate (5-ASA) drug class, similar to Olsalazine and Balsalazide.

Mode of Action

• Mesalazine has anti-inflammatory properties derived from its active 5-ASA component.
• Inhibits the lipoxygenase pathway and reduces prostaglandin and cytokine synthesis, thereby reducing local inflammation in the gut.

Indications

• Mild to moderate ulcerative colitis (both induction and maintenance therapy).
• Crohn's disease with ileocolonic involvement.

Dosage and Administration

• Ulcerative Colitis: Asacol (Mesalazine) 1.2-2.4 g/day in divided doses (tablet strength: 400 mg each).
• Distal Colitis (Proctosigmoiditis): Foam enema 1 g rectally each day for acute attacks; suppositories 250-500 mg three times daily.
• Pentasa Modified Release: 1.5-4 g/day orally in divided doses; swallow tablets whole to maintain the modified release. Available in granules and as a retention enema for bedtime use.
• Balsalazide: 750 mg capsules orally, three times daily.
• Olsalazine: 500 mg twice daily, with possible increase up to 3 g/day in divided doses if needed.

Contraindications

• Use caution in patients with renal impairment; monitor renal function periodically.
• Mesalazine has been used safely during pregnancy, but always assess the benefit-risk ratio.

Drug Interactions

• Avoid co-administration with lactulose, as it may alkalinize the colon and inhibit the conversion of mesalazine to its active form.

Common Side Effects

• Gastrointestinal: Diarrhea, nausea, vomiting.
• Hypersensitivity Reactions: Rash, headache, fever.
• Blood Disorders: Rare cases of agranulocytosis, aplastic anemia, neutropenia, and thrombocytopenia; if symptoms suggest blood dyscrasia (e.g., unexplained infection, bruising, bleeding), check a full blood count (FBC) immediately.