Usage
Mesalazine is prescribed for the treatment of mild to moderately active ulcerative colitis (inflammation of the large intestine and rectum) and Crohn’s disease. It is also used to maintain remission of these conditions. Its pharmacological classification is anti-inflammatory, specifically an aminosalicylate. Mesalazine works by reducing inflammation in the intestinal tract, likely by inhibiting prostaglandin and leukotriene synthesis.
Alternate Names
Mesalazine is also known as mesalamine or 5-aminosalicylic acid (5-ASA). Brand names include Asacol, Pentasa, Lialda, Apriso, Delzicol, Rowasa, and others.
How It Works
Pharmacodynamics: Mesalazine exerts its anti-inflammatory effects locally in the gut. The exact mechanism is unknown, but it is thought to inhibit cyclooxygenase (COX) and lipoxygenase, reducing the production of inflammatory mediators like prostaglandins and leukotrienes. It may also modulate inflammatory cytokines and immune cell function.
Pharmacokinetics: Absorption varies depending on the formulation. Immediate-release mesalazine is absorbed extensively and rapidly, while modified-release formulations have lower and more localized absorption. Mesalazine is rapidly metabolized in the colon wall and liver to N-acetyl-5-aminosalicylic acid (N-Ac-5-ASA). Elimination is primarily through fecal excretion (72%), with some renal excretion (19-30%).
Dosage
Standard Dosage
Adults:
- Oral: For active ulcerative colitis: 2.4g to 4.8g daily, taken once daily or in divided doses. For maintenance of remission: 1.6g to 2.4g daily, once daily.
- Rectal: 1000 mg suppository or 4g enema once daily at bedtime.
Children:
Oral: 20-30mg/kg body weight daily, in divided doses. Dosage should be individualized based on age, weight, and disease severity. Use in children under 5 is not well established.
Special Cases:
- Elderly Patients: No specific dosage adjustments are usually necessary, but monitoring renal function is recommended.
- Patients with Renal Impairment: Use with caution. In severe renal impairment (GFR <30 ml/min), mesalazine is contraindicated.
- Patients with Hepatic Dysfunction: Use with caution. Monitor liver function.
- Patients with Comorbid Conditions: Individualized dosing may be necessary.
Clinical Use Cases
Mesalazine is not typically used in clinical settings like intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations. Its primary use is in the management of inflammatory bowel diseases.
Dosage Adjustments
Dosage adjustments may be necessary in patients with renal or hepatic impairment, or in those experiencing adverse effects.
Side Effects
Common Side Effects:
Headache, abdominal pain, nausea, vomiting, diarrhea, flatulence, dyspepsia, and flu-like symptoms.
Rare but Serious Side Effects:
Myocarditis, pericarditis, pancreatitis, nephritis, hepatitis, blood disorders (including agranulocytosis, aplastic anemia, and thrombocytopenia), pneumonitis, allergic reactions, severe skin reactions (including Stevens-Johnson syndrome and toxic epidermal necrolysis).
Long-Term Effects:
Chronic kidney disease has been reported with long-term use.
Adverse Drug Reactions (ADR):
Severe allergic reactions, blood dyscrasias, and severe skin reactions.
Contraindications
Hypersensitivity to salicylates, severe renal or hepatic impairment.
Drug Interactions
May interact with azathioprine, 6-mercaptopurine, and nephrotoxic agents (including NSAIDs).
Pregnancy and Breastfeeding
Pregnancy Safety Category B. Mesalazine is excreted in breast milk. Use with caution.
Drug Profile Summary
- Mechanism of Action: Anti-inflammatory; inhibits prostaglandin and leukotriene synthesis.
- Side Effects: Headache, gastrointestinal upset, rare but serious cases of organ inflammation (heart, pancreas, kidney, liver), and blood disorders.
- Contraindications: Hypersensitivity to salicylates, severe renal or hepatic impairment.
- Drug Interactions: Azathioprine, 6-mercaptopurine, nephrotoxic agents.
- Pregnancy & Breastfeeding: Category B; excreted in breast milk.
- Dosage: Varies by indication and formulation. Adults: 2.4-4.8g daily for active ulcerative colitis, 1.6-2.4g daily for maintenance.
- Monitoring Parameters: Renal function, liver function, complete blood count.
Popular Combinations
Often combined with corticosteroids for the initial treatment of moderate to severe ulcerative colitis.
Precautions
Monitor renal and hepatic function. Patients should report any signs of blood disorders or allergic reactions immediately.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Mesalazine?
A: It varies depending on the formulation, indication, and patient-specific factors. For adults with active ulcerative colitis, the oral dose is 2.4g to 4.8g daily, either once daily or in divided doses. For maintenance of remission, the dose is 1.6g to 2.4g daily, once daily. Pediatric dosing is 20-30mg/kg body weight daily, in divided doses.
Q2: What are the common side effects of Mesalazine?
A: Common side effects include headache, abdominal pain, nausea, vomiting, diarrhea, flatulence, and dyspepsia.
Q3: What are the serious side effects of Mesalazine?
A: Rare but serious side effects include myocarditis, pericarditis, pancreatitis, nephritis, hepatitis, blood disorders, and allergic reactions.
Q4: Is Mesalazine safe during pregnancy?
A: Mesalazine is classified as Pregnancy Category B. While studies have not shown a significant risk to the fetus, it should be used with caution during pregnancy, especially during the first trimester.
Q5: Can Mesalazine be used in children?
A: Yes, but dosing should be individualized based on age, weight, and disease severity. The recommended dose is 20-30mg/kg body weight daily, in divided doses.
Q6: How does Mesalazine differ from Sulfasalazine?
A: Both are aminosalicylates, but sulfasalazine contains a sulfapyridine component, which is responsible for many of its side effects. Mesalazine lacks this component, leading to a better tolerability profile.
Q7: What should I monitor in patients taking Mesalazine?
A: Monitor renal and hepatic function, as well as complete blood count, especially in patients with pre-existing renal or hepatic disease, or those experiencing adverse effects.
Q8: Can Mesalazine be crushed or chewed?
A: Modified-release formulations should not be crushed or chewed, as this can interfere with their targeted delivery to the colon. Some immediate-release tablets can be dispersed in water if swallowing is difficult.
Q9: How long does it take for Mesalazine to work?
A: Improvement is usually seen within 1-3 months of starting treatment.
Q10: What should patients do if they miss a dose?
A: They should take the missed dose as soon as they remember, unless it is almost time for the next dose. They should not take two doses at the same time.
