Mesalazine information from DrugsUpdate
L - Caution when used during lactation
LI - Lab *
Mesalazine, also known as Mesalamine or 5-aminosalicylic acid (5-ASA), is an anti-inflammatory drug used to treat inflammation of the digestive tract ulcerative colitis and mild to moderate Crohn's disease. 5-ASA produces this effect at least partly through modulation of the endocannabinoid system by means of elevating anandamide levels in the gut. Mesalazine is a bowel-specific aminosalicylate drug that acts locally in the gut and has its predominant actions there, thereby having few systemic side effects. As a derivative of salicylic acid, 5-ASA is also an antioxidant that traps free radicals, which are potentially damaging byproducts of metabolism. 5-ASA is considered the active moiety of sulfasalazine, which is metabolized to it.
Mesalazine is considered to be the active moiety of sulfasalazine. The mechanism of action is uncertain, but may be due to its ability to inhibit local chemical mediators of the inflammatory response especially leukotriene synthesis in the GI mucosa. Action may be topical in terminal ileum and colon rather than systemic.
Absorption variable, depending on formulation and route of admin.
Enters breast milk and crosses placenta (small amounts) after oral dosing; protein-binding: 40-80%. Distribution into other tissues: variable depending on route of admin.
Exact metabolism pathways not established. Main site of metabolism is probably liver with some N-acetylation occurring in the intestinal wall and/or lumen (where intestinal flora are involved in the acetylation).
Dependant upon route of admin. Eliminated via urine <8% as unchanged metabolites) and faeces (<2%).
Abdominal pain (if new abdominal pain - consider pancreatitis); headache, nausea; flu; fatigue; fever, rash; sore throat; diarrhoea; joint pain; dizziness; bloating; back pain; haemorrhoids; itching; rectal pain, constipation; hair loss; intolerance syndrome; peripheral oedema; UTI; myocarditis, pre-existing pericarditis; pancreatitis; nephritis; hepatitis; lupus-like syndrome; alopecia; myalgia, arthralgia; increased liver enzyme values.
Potentially Fatal: Blood dyscrasias, aplastic anaemia, agranulocytosis; renal toxicity.
Mild to moderate impaired renal or hepatic function (test serum creatinine before treatment, every 3 months for 1st years, every 6 months for next 4 years, then annually). Elderly; active peptic ulcer; pregnancy, lactation; patients predisposed to pericarditis or myocariditis. Counsel patients to report any unexplained bleeding, bruising, purpura, sore throat, fever or malaise during treatment; perform blood count and stop treatment if blood dyscrasias suspected. Counsel patients taking delayed release tablets to report repeatedly unbroken or partially broken tablets in their faeces. Pyloric stenosis may delay release into colon.
Do not give with lactulose or other drugs which lower pH for they prevent release of mesalazine. May decrease digoxin absorption.
Adult: Dose is dependant on preparation and brand used. Pentasa® tablets: Acute attack: Initially, up to 4 g daily in 2-3 divided doses; maintenance of remission: Initially, 1.5 g daily in 2-3 divided doses, adjust subsequently based on response. Pentasa® granules: Acute attack: Initially, up to 4 g daily in 2-4 doses; maintenance of remission: 2 g daily in 2 divided doses. Asacol® tablets: Acute attack: Initially, 2.4 g daily in divided doses; maintenance of remission: 1.2-2.4 g daily in divided doses. Salofalk® tablets: Acute attack: Initially, 1.5 g daily in 3 divided doses; maintenance of remission: 0.75-1.5 g daily in divided doses. Salofalk® granules: Acute attack: Initially, 1.5-3 g daily in 1-3 divided doses; maintenance of remission: 1.5 g daily in 3 divided doses.
Child: Dose is dependant on preparation and brand used. Pentasa® tablets: 5-15 years: Acute attack: 15-20 mg/kg (max: 1 g) tid; maintenance of remission: 10 mg/kg (max: 500 mg) 2-3 times daily. Pentasa® granules: 5-12 years: Acute attack: 15-20 mg/kg (max: 1 g) tid; maintenance of remission: 10 mg/kg (max: 500 mg) 2-3 times daily. Asacol® tablets: 12-18 years: Acute attack: Initially, 2.4 g daily in divided doses; maintenance of remission: 1.2-2.4 g daily in divided doses. Salofalk® tablets: 12-18 years: Acute attack: Initially, 1.5 g daily in 3 divided doses; maintenance of remission: 250-500 mg 2-3 times daily. Salofalk® granules: 6-12 years: Acute attack: 10-15 mg/kg (max: 1 g) tid; maintenance of remission: 7.5-15 mg/kg (max: 500 mg) bid or 250 mg tid for patients weighing <40 kg.
Cl (ml/min) Dosage Recommendation
Hepatic impairment: Avoid in severe impairment.
Adult: Pentasa® suppository or suspension enema: 1 g daily. Asacol® suppository: 0.75-1.5 g daily in divided doses; Asacol ® foam enema: 1 g daily if disease affects the rectosigmoid regions or 2 g daily if disease affects the descending colon. Salofalk® suppository: 0.5-1 g bid-tid; Salofalk® foam or suspension enema: 2 g daily.
Child: As suppository: Pentasa®: 12-18 years: 1 g daily for 2-4 weeks. Salofalk®: 12-18 years: 0.5-1 g bid-tid according to response.
CrCl (ml/min) Dosage Recommendation
Hepatic impairment: Avoid in severe impairment.
Should be taken with food. (Take after meals.)
List of Contraindications
Caution when used during pregnancy
Category B: Either animal-reproduction studies have not demonstrated a foetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the 1st trimester (and there is no evidence of a risk in later trimesters).
Caution when used during lactation
Hypersensitivity to mesalazine, salicylates and sulfasalazine. Severe impaired renal (CrCl < 20 ml/min) or hepatic function. Children <2 years.
Tablets: store at below 25°C. Capsule: protect from light and store at 15-30°C.
Store <25°C; may be refrigerated; do not freeze. Protect from direct heat, light and humidity.
Interferes with tests for glucosuria using copper reagents and for urobilinogen using Erhlick's reagent.