Mesalazine [5-aminosalicylic acid]

Mesalazine is indicated for

• Treatment of mild to moderately active Ulcerative Colitis & & Crohn’s Disease
• Maintenance of remission of Ulcerative Colitis
• Maintenance of remission of Crohn’s disease

The mechanism of action of Mesalamine is unknown, but appears to be topical rather than systemic. Mucosal production of Arachidonic Acid metabolites, both through the cyclooxygenase pathways, that is, prostanoids, and through the lipoxygenase pathways, that is, leukotrienes and hydroxyeicosatetraenoic acids, is increased in patients with chronic infammatory bowel disease. Mesalamine diminishes infammation by blocking cyclooxygenase and inhibiting prostaglandin production in the colon.

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.

Pediatrics: The safety and efficacy in children below 6 years of age have not been established. There is only limited documentation for an effect in children (age 6-18 years).

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.

Administration

The granules must not be chewed. The contents of the sachet should be emptied onto the tongue and washed down with some water or orange juice. Alternatively, the entire content of the sachet can be taken with yogurt and consumed immediately.

Concurrent use of other known nephrotoxic agents such as NSAIDs and Azathioprine may increase the risk of renal reactions.

Hypersensitivity to salicylates or to any other component of the formulation.

The commonly reported adverse events are headache, nausea, dizziness, asthenia, dyspepsia, vomiting, pruritus etc.

It should be given in pregnancy only if the potential beneft justifes the potential risk to the fetus. Caution is advised when it is administered to a nursing mother.

Patients with pyloric stenosis may have prolonged gastric retention of Mesalamine tablets which could delay release of Mesalamine in the colon. Renal impairment, including minimal change nephropathy and acute and chronic interstitial nephritis has been reported in patients taking Mesalamine. Therefore, caution should be exercised when using Mesalamine in patients with known renal dysfunction or history of renal disease. Patients should have renal function monitored, prior to treatment start and then it should be monitored periodically during treatment. There have been reports of hepatic failure in patients with pre-existing liver disease who have been administered Mesalamine. Caution should be exercised when administering Mesalamine to patients with liver impairment.

There is no specifc antidote for Mesalamine overdose. Treatment for suspected acute severe toxicity should be symptomatic and supportive. This may include prevention of further gastrointestinal tract absorption, correction of fuid electrolyte imbalance and maintenance of adequate renal function. This is a pH dependent delayed-release product and this factor should be considered when treating a suspected over dose.

Aminosalicylates

Geriatrics: Patients who are 65 years or older, caution should be taken to closely monitor blood cell counts during Mesalamine therapy.

Elderly: Because elderly patients are more likely to have decreased renal function, care should be taken when prescribing this drug therapy. It is recommended that all patients have an evaluation of renal function prior to initiation of Mesalamine tablets. Monitor blood cell counts during drug therapy.

Paediatric: Safety and effectiveness have not been established.

Store below 30 0 C. Protect from light and moisture. Keep all medicines out of the reach of children.