Asacol (mesalamine) is a prescription medication specifically designed for the treatment of mild to moderate ulcerative colitis, a form of inflammatory bowel disease. It belongs to the class of aminosalicylates and works locally in the colon to reduce inflammation, thereby helping to induce and maintain remission. This delayed-release formulation ensures that the active ingredient is delivered directly to the site of inflammation, minimizing systemic absorption and optimizing therapeutic efficacy for appropriate patients under medical supervision.

Features

• Active ingredient: Mesalamine (also known as 5-aminosalicylic acid or 5-ASA)
• Formulation: Delayed-release tablets designed for targeted colonic release
• Available strengths: 400 mg and 800 mg tablets
• pH-dependent coating that dissolves at pH 7 or higher, typically in the terminal ileum and colon
• Designed to minimize systemic absorption and maximize local anti-inflammatory action
• Biconvex, dark blue coated tablets imprinted with identification codes

Benefits

• Effectively reduces inflammation in the colon and rectum, providing symptomatic relief from ulcerative colitis flares
• Helps achieve and maintain clinical remission, reducing the frequency of disease exacerbations
• Targeted delivery system minimizes systemic exposure, potentially reducing the risk of broader side effects
• Supports mucosal healing, which is associated with improved long-term outcomes
• May reduce the need for corticosteroid therapy in some patients
• Convenient oral administration with well-established dosing regimens

Common use

Asacol is primarily indicated for the treatment of mildly to moderately active ulcerative colitis in adults. It is used both for induction of remission during acute flares and for maintenance of remission to prevent relapse. The medication is particularly effective for distal colitis involving the left colon, though it can be used for more extensive disease as well. Clinical studies have demonstrated its efficacy in improving stool frequency, reducing rectal bleeding, and achieving endoscopic improvement in appropriately selected patients.

Dosage and direction

For the treatment of active ulcerative colitis: The typical dosage is 2.4 grams per day administered orally in divided doses (800 mg tablet three times daily or 400 mg tablet dosing as directed) for 6 weeks. For maintenance of remission of ulcerative colitis: The recommended dosage is 1.6 grams per day administered orally in divided doses. Tablets should be swallowed whole and not crushed, chewed, or broken, as this would compromise the delayed-release mechanism. Administration with food may help some patients with gastrointestinal tolerance, though this is not required for efficacy. Dosage adjustments may be necessary for patients with renal impairment, and treatment should be guided by a gastroenterologist based on individual patient response and tolerance.

Precautions

Patients should be monitored for renal function before starting treatment and periodically during therapy, as mesalamine has been associated with renal toxicity, including interstitial nephritis. Those with pre-existing renal impairment require careful assessment and possibly alternative treatment options. Hepatic function should also be monitored, as rare cases of hepatitis have been reported. Patients with pyloric stenosis may experience delayed gastric emptying, which could affect drug delivery to the colon. Caution is advised in patients with sulfasalazine sensitivity, though cross-sensitivity appears to be uncommon. Sun protection is recommended as photosensitivity reactions have been reported. Regular follow-up with a gastroenterologist is essential to monitor treatment response and adjust therapy as needed.

Contraindications

Asacol is contraindicated in patients with known hypersensitivity to mesalamine, salicylates, or any component of the formulation. It should not be used in patients with severe renal impairment (glomerular filtration rate less than 30 mL/min/1.73m²) due to increased risk of nephrotoxicity. The medication is also contraindicated in patients with active peptic ulcer disease. Those who have experienced previous reactions to sulfasalazine should use Asacol with caution, though true cross-reactivity is rare. The safety and effectiveness in pediatric patients have not been established, and use is not recommended in this population.

Possible side effects

Common side effects (occurring in >1% of patients) include headache, abdominal pain, nausea, diarrhea, flatulence, and exacerbation of colitis symptoms. Less frequently reported adverse reactions include rash, pruritus, fever, dizziness, and hair loss. Serious but rare side effects requiring immediate medical attention include renal impairment (manifested as elevated creatinine, proteinuria, or hematuria), pancreatitis, hepatitis, pericarditis, myocarditis, and blood dyscrasias such as agranulocytosis or aplastic anemia. Pulmonary toxicity including interstitial lung disease has been reported in rare instances. Any signs of hypersensitivity reactions, including difficulty breathing, swelling of face or throat, or severe skin reactions, warrant immediate discontinuation and medical evaluation.

Drug interaction

Mesalamine may potentiate the effects of anticoagulants like warfarin, increasing the risk of bleeding, requiring closer monitoring of coagulation parameters. Concurrent use with other nephrotoxic agents (such as NSAIDs, aminoglycosides, or cyclosporine) may increase the risk of renal adverse events. Azathioprine or 6-mercaptopurine used concomitantly with mesalamine may increase the risk of blood dyscrasias. The delayed-release formulation may affect the absorption of other medications, particularly those with pH-dependent absorption characteristics. Proton pump inhibitors that increase gastric pH may theoretically affect the release characteristics of Asacol, though clinical significance remains uncertain. Healthcare providers should review all concomitant medications, including over-the-counter products and supplements, before initiating therapy.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is almost time for the next scheduled dose. In that case, patients should skip the missed dose and resume their regular dosing schedule. Doubling the dose to make up for a missed dose is not recommended, as this may increase the risk of adverse effects. Patients should maintain a consistent dosing schedule to ensure optimal therapeutic levels in the colon. If multiple doses are missed or uncertainty exists about how to proceed, patients should consult their healthcare provider for guidance rather than adjusting the regimen independently.

Overdose

Cases of mesalamine overdose have been reported with symptoms including nausea, vomiting, diarrhea, sweating, dizziness, tinnitus, and respiratory distress. Severe overdose may lead to metabolic acidosis, renal impairment, or central nervous system effects including confusion or seizures. There is no specific antidote for mesalamine overdose. Management is supportive and symptomatic, including correction of electrolyte imbalances and maintenance of adequate hydration. Hemodialysis may be considered in severe cases, though the extent of mesalamine removal through dialysis is limited due to high protein binding. In case of suspected overdose, immediate medical attention should be sought, and the poison control center should be contacted for specific management recommendations.

Storage

Asacol tablets should be stored at controlled room temperature between 20°C to 25°C (68°F to 77°F), with excursions permitted between 15°C to 30°C (59°F to 86°F). The medication should be kept in its original container with the lid tightly closed to protect from moisture and light. Tablets should not be stored in bathroom cabinets or other areas subject to high humidity. Keep out of reach of children and pets. Do not use beyond the expiration date printed on the packaging. Proper disposal of unused medication should follow local regulations, typically through medication take-back programs or according to specific disposal instructions.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Asacol is a prescription medication that should be used only under the supervision of a qualified healthcare professional. Individual response to treatment may vary, and the appropriate use of this medication requires consideration of the patient’s specific medical condition, history, and other factors. Patients should not initiate, discontinue, or change their dosage without consulting their physician. The complete prescribing information should be reviewed before initiating therapy. This summary does not include all possible information about risks, uses, directions, or precautions associated with this medication.

Reviews

Clinical studies have demonstrated that Asacol is effective in inducing remission in approximately 40-50% of patients with mild to moderate ulcerative colitis after 6 weeks of treatment, with maintenance therapy showing significantly reduced relapse rates compared to placebo. Gastroenterologists generally regard mesalamine preparations as first-line therapy for mild to moderate ulcerative colitis due to their favorable safety profile and established efficacy. Patient experiences vary, with many reporting significant improvement in symptoms including reduced bowel frequency, less rectal bleeding, and improved quality of life. Some patients report gastrointestinal side effects that may limit tolerability, though these often diminish with continued use or dose adjustment. The convenience of oral administration is frequently cited as a significant advantage over rectal formulations, though combination therapy is sometimes employed for more extensive disease.