Introduction
Mesalazine, also known as 5-aminosalicylic acid (5-ASA), is an anti-inflammatory drug used primarily to treat inflammatory bowel diseases, including ulcerative colitis and Crohn's disease. It is a type of aminosalicylate with localized action in the gastrointestinal tract.
Uses
Mesalazine is used for:
- Treating mild to moderate ulcerative colitis.
- Maintaining remission in patients with ulcerative colitis.
- Managing Crohn's disease, particularly when there is involvement of the colon.
Mechanism of Action
Mesalazine works by inhibiting the production of inflammatory mediators, such as leukotrienes, in the gastrointestinal tract. It has a topical anti-inflammatory effect, primarily acting on the mucosal layer of the intestines. This reduces inflammation and alleviates symptoms associated with inflammatory bowel diseases.
How Long Does It Take to Work?
The onset of action of mesalazine can vary, but patients typically start to see improvements within 1 to 2 weeks of starting treatment. Full benefits may take several weeks to achieve, depending on the severity of the condition and individual response to the medication.
Absorption
Mesalazine is minimally absorbed systemically. It is designed to act locally within the gastrointestinal tract, particularly in the colon. The drug is absorbed in small amounts from the gastrointestinal tract, with the majority of the medication exerting its effects directly on the intestinal mucosa.
Route of Elimination
Mesalazine is primarily excreted through the feces. The small amount of drug absorbed systemically is metabolized by the liver and then excreted in the urine. Minimal systemic exposure helps to reduce the risk of systemic side effects.
Dosage
Tablet dose: Treatment of mild to moderate Ulcerative Colitis-- Adult: For adults, the recommended dosage of Mesalazine is 800 mg (two 400 mg tablets) three times daily for a duration of 6 weeks. However, a dose up to 4.8 g/day in divided doses may be given if needed.
- Child: For child patients 5 years of age and older, daily dosage of Mesalazine is as follows-
| Weight Group (kg) | Morning Dosage | Evening Dosage | Duration |
| 17 to <33 | two 400 mg tablets | one 400 mg tablet | 6 weeks |
| 33 to <54 | three 400 mg tablets | two 400 mg tablets |
- Adult: The recommended dosage of Mesalazine is 1.6 g (four 400 mg tablets) daily in two to four divided doses. However, a dose up to 2.4 g/day in divided doses may be given if needed.
- Adult: 1.2-2.4 g daily in divided dose.
- Child: 400-800 mg 3 times daily.
Prolonged release granules dose: Treatment of ulcerative colitis-
Adults:
- Active disease: Individual dosage, up to 4 gm mesalazine once daily or divided into 2-4 doses.
- Maintenance treatment: Individual dosage. Recommended dosage, 2 gm mesalazine once daily.
Children 6 years of age and older:
- Active disease: To be determined individually, starting with 30-50 mg/kg/day in divided doses. Maximum dose: 75 mg/kg/day in divided doses. The total dose should not exceed 4 g/day (maximum adult dose).
- Maintenance treatment: To be determined individually, starting with 15-30 mg/kg/day in divided doses. The total dose should not exceed 2 g/day (recommended adult dose).
- It is generally recommended that half the adult dose may be given to children up to a body weight of 40 kg; and the normal adult dose to those above 40 kg.
The dosage of mesalazine varies depending on the specific formulation and the condition being treated:
- For ulcerative colitis: Typically 2.4 to 4.8 grams per day, administered in divided doses.
- For Crohn's disease: Dosages can range from 2.4 to 4.8 grams per day, also administered in divided doses.
Administration
Mesalazine can be administered orally in the form of tablets, capsules, or granules. It is also available as a rectal preparation (suppositories or enemas) for localized treatment of ulcerative colitis. Follow specific dosing instructions provided by a healthcare provider to ensure effective treatment.
Side Effects
Common side effects include:
- Gastrointestinal symptoms such as nausea, abdominal pain, and diarrhea.
- Headache and dizziness.
- Rash or pruritus.
Toxicity
Toxicity from mesalazine is rare but can occur. Symptoms of toxicity may include severe gastrointestinal distress, kidney dysfunction, and severe allergic reactions. Dose adjustments or discontinuation of the medication may be required in cases of toxicity.
Precautions
Precautions include:
- Monitoring renal function, as mesalazine can affect kidney function in some patients.
- Using with caution in patients with a history of hypersensitivity to salicylates or sulfasalazine.
- Monitoring for gastrointestinal symptoms, especially during the initial phase of treatment.
Interaction
Mesalazine may interact with:
- Other medications affecting kidney function, which can increase the risk of renal adverse effects.
- Drugs that alter gastrointestinal motility, potentially affecting the drug's absorption.
Disease Interaction
Use mesalazine with caution in patients with:
- Renal impairment or a history of kidney disease.
- Active gastrointestinal bleeding or obstruction.
Drug Interaction
Drug interactions may include:
- Medications that affect renal function, such as diuretics or ACE inhibitors.
- Drugs that may influence gastrointestinal motility or pH, affecting mesalazine absorption.
Food Interactions
There are no specific food interactions with mesalazine. However, managing gastrointestinal symptoms such as nausea may require dietary adjustments. Follow dietary recommendations provided by your healthcare provider if needed.
Pregnancy Use
Mesalazine is generally considered safe for use during pregnancy, particularly if the benefits outweigh the risks. It is classified as a Category B drug, meaning that animal studies have not shown any risk to the fetus, but there are limited human studies. Consult with a healthcare provider before use during pregnancy.
Lactation Use
Mesalazine is excreted in breast milk in small amounts. It is generally considered safe for use during lactation, but breastfeeding mothers should discuss the benefits and risks with their healthcare provider. Regular monitoring of the infant may be advised.
Acute Overdose
Acute overdose of mesalazine may lead to severe gastrointestinal symptoms, including nausea, vomiting, and abdominal pain. In case of overdose, seek immediate medical attention. Supportive care and symptomatic treatment may be required.
Contraindication
Contraindications include:
- Hypersensitivity to mesalazine or any of its components.
- Severe renal impairment or active renal disease.
Use Direction
Follow the specific dosing and administration instructions provided by your healthcare provider. Adhere to the prescribed regimen and schedule to achieve optimal results and minimize potential side effects.
Storage Conditions
Store mesalazine at room temperature, away from light and moisture. Keep the medication out of reach of children and use only as directed. Do not use beyond the expiration date.
Volume of Distribution
The volume of distribution of mesalazine is not well-characterized due to its limited systemic absorption. Most of the drug's action is localized to the gastrointestinal tract.
Half Life
The half-life of mesalazine is approximately 1 to 2 hours. However, the duration of its therapeutic effect may extend beyond this due to its local action in the gastrointestinal tract.
Clearance
Mesalazine is primarily cleared through the feces with minimal systemic metabolism. The drug's systemic clearance is minimal due to its localized action and limited absorption.
