Mesalamine

# Mesalamine ## Overview - **Classification**: 5-aminosalicylate (5-ASA), anti-inflammatory agent. - **Mechanism**: Modulates local inflammatory mediators in the colon, inhibits NF-κB, reduces oxidative stress. Acts topically on the bowel mucosa. ## Primary Indications 1. **Ulcerative Colitis (UC)**: Induction and maintenance of remission in mild to moderate active UC. 2. **Proctitis/Proctosigmoiditis**: Localized treatment of inflammation in the rectum and sigmoid colon. 3. **Crohn's Disease**: May be used for mild Crohn's disease, but efficacy is less established than for UC. ## Adult Dosing ### Standard Dosing **Ulcerative Colitis - Induction of Remission (Oral)** - **Dose**: **2.4 g** to **4.8 g** daily - **Frequency**: Once daily or divided **2-3 times daily** - **Route**: Oral (extended-release tablets/capsules) - **Duration**: Up to **6-8 weeks** or until remission **Ulcerative Colitis - Maintenance of Remission (Oral)** - **Dose**: **1.2 g** to **2.4 g** daily - **Frequency**: Once daily or divided **2 times daily** - **Route**: Oral **Ulcerative Colitis (Proctitis/Proctosigmoiditis) - Induction (Rectal)** - **Suppository**: **1000 mg** once daily at bedtime - **Enema**: **4 g** per **60 mL** once daily at bedtime - **Route**: Rectal - **Duration**: Up to **3-6 weeks** or until remission **Ulcerative Colitis (Proctitis/Proctosigmoiditis) - Maintenance (Rectal)** - **Suppository**: **1000 mg** once daily or **3 times weekly** at bedtime - **Enema**: **4 g** per **60 mL** **2-3 times weekly** at bedtime - **Route**: Rectal ### Dose Adjustments - **Renal Impairment**: - Use with caution. Monitor renal function closely. - Avoid if CrCl < **30 mL/min**. - **Hepatic Impairment**: - Use with caution. No specific dose adjustments recommended. - **Elderly Patients**: - Use with caution due to potential age-related decrease in renal function. ## Pediatric Dosing ### Neonates (0-28 days) - **Dose**: Not recommended. - **Frequency**: N/A - **Maximum**: N/A - **Special Notes**: Safety and efficacy not established; avoid use due to potential systemic absorption. ### Infants (1-12 months) - **Dose**: Not recommended. - **Frequency**: N/A - **Maximum**: N/A - **Special Notes**: Limited data; risks generally outweigh benefits in this age group. ### Children (1-12 years) **Ulcerative Colitis - Induction of Remission (Oral)** - **Dose**: **30-50 mg/kg/day** - **Frequency**: Divided **2-3 times daily** - **Maximum**: **4.8 g/day** - **Special Notes**: Consider specific formulation (e.g., granules, sprinkles) for age-appropriate administration. **Ulcerative Colitis - Maintenance of Remission (Oral)** - **Dose**: **15-30 mg/kg/day** - **Frequency**: Divided **2 times daily** - **Maximum**: **2.4 g/day** - **Special Notes**: Monitor growth and development, assess adherence. ### Adolescents (13-18 years) **Ulcerative Colitis - Induction of Remission (Oral)** - **Dose**: Follow **adult dosing** (e.g., **2.4 g** to **4.8 g** daily) - **Frequency**: Once daily or divided **2-3 times daily** - **Maximum**: **4.8 g/day** - **Special Notes**: Use adult formulations. **Ulcerative Colitis - Maintenance of Remission (Oral)** - **Dose**: Follow **adult dosing** (e.g., **1.2 g** to **2.4 g** daily) - **Frequency**: Once daily or divided **2 times daily** - **Maximum**: **2.4 g/day** - **Special Notes**: No specific pediatric-only considerations beyond adult dosing. ## Safety Information ### Contraindications - **Absolute**: Hypersensitivity to salicylates (aspirin) or aminosalicylates. - **Absolute**: Hypersensitivity to any component of the specific mesalamine product. - **Absolute**: Severe renal impairment (CrCl < **30 mL/min**). - **Absolute**: Severe hepatic impairment. ### Common Adverse Effects - **Very Common (>10%)**: Headache, abdominal pain, nausea, flatulence. - **Common (1-10%)**: Diarrhea, vomiting, dyspepsia, rash, fatigue, fever. - **Serious but Rare**: - Acute intolerance syndrome (worsening UC symptoms, fever, rash). - Myocarditis/pericarditis. - Nephrotoxicity (interstitial nephritis). - Hepatotoxicity, pancreatitis. - Blood dyscrasias (e.g., agranulocytosis, aplastic anemia). ### Key Drug Interactions - **NSAIDs**: Increased risk of nephrotoxicity. Monitor renal function closely. - **Azathioprine/6-Mercaptopurine (6-MP)**: Increased risk of myelosuppression. Monitor CBC. - **Antacids/PPIs**: May interfere with dissolution of certain pH-dependent mesalamine formulations (e.g., Lialda, Asacol HD). - **Lactulose/other laxatives**: May interfere with colonic delivery of rectal mesalamine. ## Monitoring & Follow-up - **Before Treatment**: - Renal function (SCr, BUN, eGFR). - Hepatic function (ALT, AST, ALP, bilirubin). - Complete Blood Count (CBC) with differential. - **During Treatment**: - Renal function: Annually or more frequently (e.g., **3 months** after initiation, then **6-12 months**). More often if risk factors. - Hepatic function: Periodically, if clinically indicated. - CBC: Periodically, especially with concurrent myelosuppressive agents. - Clinical signs: Monitor for acute intolerance syndrome (worsening abdominal pain, bloody diarrhea, fever, rash). - **Clinical Signs**: Watch for signs of nephrotoxicity (decreased urine output, swelling) or hepatotoxicity (jaundice, dark urine). ## Clinical Pearls - 💡 **Tip 1**: Different oral formulations release mesalamine at different sites/rates. Do not interchange products without clinical guidance. - 💡 **Tip 2**: Rectal formulations are critical for treating distal colitis, ensuring drug delivery directly to the inflamed area. - 💡 **Tip 3**: Counsel patients to report any unexplained fever, rash, abdominal pain, or worsening UC symptoms immediately. - 💡 **Tip 4**: Maintain adequate hydration to help prevent renal stone formation, especially during high-dose therapy. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.