What is the initial treatment for ulcerative colitis?

Initial Treatment for Ulcerative Colitis

For mild to moderately active ulcerative colitis, the initial treatment should be aminosalicylates (5-ASA), with a combination of oral mesalamine ≥2.4 g/day and rectal mesalamine ≥1 g/day for optimal efficacy. 1

Treatment Algorithm Based on Disease Location and Severity

Proctitis (Distal Disease)

• First-line: Rectal 5-ASA (mesalamine) suppositories or enemas at a dosage of 1 g daily 1
• Rectal 5-ASA is more effective than rectal corticosteroids for inducing remission 1
• If no response to rectal 5-ASA therapy, consider rectal corticosteroids as second-line therapy 1

Left-Sided Colitis

• First-line: Combination of rectal 5-ASA enemas (≥1 g/day) plus oral mesalamine (≥2.4 g/day) 1
• This combination is more effective than either oral or topical aminosalicylates alone 1
• Once-daily dosing with mesalamine is as effective as divided doses and may improve adherence 1

Extensive Colitis

• First-line: Combination of rectal 5-ASA enemas (1 g/day) plus oral mesalamine (≥2.4 g/day) 1
• For moderate to severe disease, systemic corticosteroids are appropriate 1
• Severe extensive colitis requires hospital admission for intensive treatment 1

Dose Considerations and Response Assessment

• Oral mesalamine at ≥2 g/day is more effective than lower doses for inducing remission 1
• Patients with moderate disease may benefit from higher doses up to 4.8 g/day 1
• Patients should be evaluated for lack of symptomatic response to 5-ASA therapy within 4-8 weeks to determine the need for treatment modification 1
• If symptoms deteriorate or rectal bleeding persists beyond 10-14 days, consider adding oral corticosteroids 1

Escalation of Therapy

• For patients who fail to respond to 5-ASA therapy, oral corticosteroids (prednisolone 40 mg daily) are recommended as second-line therapy 1
• Budesonide MMX 9 mg/day is an alternative for patients wishing to avoid systemic corticosteroids, particularly effective in left-sided disease 1
• For moderate to severe UC, prednisolone 40 mg daily weaning over 6-8 weeks is recommended 1

Maintenance Therapy

• After achieving remission, continue with the same therapy that induced remission 1
• For 5-ASA-induced remission, continue oral therapy of at least 2 g/day to maintain remission 1
• Lifelong maintenance therapy is generally recommended, especially for patients with left-sided or extensive disease 1

Special Considerations

• For patients with moderate to severe disease, the American Gastroenterological Association recommends early use of biologic agents rather than gradual step-up after 5-ASA failure 2
• Infliximab is approved for reducing signs and symptoms, inducing and maintaining clinical remission and mucosal healing, and eliminating corticosteroid use in patients with moderately to severely active UC who have had inadequate response to conventional therapy 3
• Patients who require two or more courses of corticosteroids in the past year, or who become corticosteroid-dependent or refractory, require treatment escalation with thiopurines, anti-TNF therapy, vedolizumab, or tofacitinib 1

Common Pitfalls to Avoid

• Switching between different oral 5-ASA formulations is not recommended for patients who have failed to respond to one formulation 1
• Oral corticosteroids should not be used for maintenance of remission due to side effects 1
• Delaying effective treatment in moderate-severe UC may increase risk of complications, hospitalization, and colectomy 2
• Patients on long-term 5-ASA therapy should have renal function checked before starting, after 2-3 months, and then annually long-term 1

Monitoring Response

• Evaluate patients within 4-8 weeks of initiating 5-ASA therapy 1
• If rectal bleeding persists beyond 10-14 days or symptoms deteriorate, consider escalating therapy 1
• Endoscopic healing is an important treatment goal, with rates of 27.6% reported with budesonide MMX 1

Remember that treatment approach should be tailored to disease distribution (proctitis vs. left-sided vs. extensive colitis) and severity, with combination therapy of oral and topical 5-ASA being more effective than either alone for most presentations 2, 4.