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Drugs, Supplies and Delivery
Mesalamine (5-ASA)
Mesalamine, also known as 5-aminosalicylic acid (5-ASA), is a first-line treatment for inflammatory bowel disease (IBD), including ulcerative colitis and Crohn’s disease. It works locally in the gastrointestinal tract to reduce inflammation and maintain remission. This article synthesizes information from the British National Formulary (BNF), Lippincott Textbook of Pharmacology, and Lange Basic & Clinical Pharmacology to provide a detailed overview of mesalamine, including its mechanism, uses, dosing, side effects, precautions, and drug interactions.
Mesalamine exerts its anti-inflammatory effects by:
- Inhibiting prostaglandin and leukotriene synthesis: Reduces the production of pro-inflammatory mediators (Lippincott, Lange).
- Scavenging reactive oxygen species: Decreases oxidative stress in the intestinal mucosa (BNF).
- Modulating immune response: Suppresses the activity of immune cells (e.g., neutrophils, T-cells) in the gut, preventing tissue damage (Lippincott).
Mesalamine is designed to act locally in the colon, with minimal systemic absorption, reducing the risk of systemic side effects (Lange).
- Ulcerative Colitis:
- Induces and maintains remission in mild to moderate ulcerative colitis (BNF).
- Crohn’s Disease:
- Used for mild to moderate Crohn’s disease, particularly affecting the colon (Lippincott).
- Proctitis and Proctosigmoiditis:
- Effective in treating inflammation limited to the rectum and sigmoid colon (Lange).
- Oral Formulations:
- Tablets/Capsules (e.g., Asacol®, Pentasa®): 1.2–4.8 g/day in divided doses (BNF).
- Extended-Release Tablets (e.g., Lialda®): 2.4–4.8 g once daily (Lippincott).
- Rectal Formulations:
- Suppositories (e.g., Canasa®): 500 mg–1 g once or twice daily for proctitis (Lange).
- Enemas (e.g., Rowasa®): 4 g nightly for proctosigmoiditis (BNF).
Administration:
- Oral formulations should be taken with or without food, depending on the product.
- Rectal formulations should be used at bedtime for optimal retention and efficacy (Lippincott).
- Common: Headache, nausea, abdominal pain, and flatulence (Lippincott).
- Serious:
- Renal Impairment: Rare cases of interstitial nephritis; monitor renal function (Lange).
- Hypersensitivity Reactions: Rash, fever, and pancreatitis (BNF).
- Blood Disorders: Leukopenia, thrombocytopenia, and anemia (Lippincott).
- Renal Impairment: Use with caution; monitor renal function regularly (BNF).
- Pregnancy and Lactation: Generally considered safe, but consult a healthcare provider (Lippincott).
- Hypersensitivity: Contraindicated in patients with known hypersensitivity to salicylates or sulfonamides (Lange).
- Warfarin: Mesalamine may increase the risk of bleeding (BNF).
- Azathioprine/6-Mercaptopurine: Increased risk of myelosuppression (Lippincott).
- NSAIDs: May reduce the efficacy of mesalamine and increase the risk of nephrotoxicity (Lange).
Mesalamine is the generic name for this medication. It is marketed under various brand names, including Asacol®, Pentasa®, Lialda®, Canasa®, and Rowasa®. Generic versions are widely available and cost-effective.
