What is the initial treatment for a newly diagnosed patient with ulcerative colitis?

Initial Treatment for Newly Diagnosed Ulcerative Colitis

Start with combination therapy of topical mesalamine (≥1 g/day) plus oral mesalamine (≥2.4 g/day), tailored to disease extent and severity. 1, 2

Treatment Algorithm Based on Disease Extent

For Proctitis (Rectum Only)

• Begin with mesalamine 1 g suppository once daily as the preferred initial treatment 1, 2
• Suppositories deliver medication more effectively to the rectum than foam or enemas and are better tolerated 1
• Topical mesalamine is more effective than topical corticosteroids for proctitis 1
• Add oral mesalamine ≥2.4 g/day to the suppository for enhanced effectiveness over either therapy alone 1

For Left-Sided Colitis

• Start with mesalamine enema ≥1 g/day combined with oral mesalamine ≥2.4 g/day 1, 2
• This combination is more effective than oral therapy alone, topical therapy alone, or topical steroids 1, 2
• Once-daily dosing is as effective as divided doses and improves adherence 1, 2

For Extensive Colitis

• Initiate mesalamine enema 1 g/day plus oral mesalamine ≥2.4 g/day 1
• For moderate to severe activity or mesalamine failure, escalate to prednisolone 40 mg daily 1
• Severe extensive colitis requires hospital admission for intensive intravenous treatment 1

Treatment Escalation Strategy

If no improvement within 10-14 days or symptoms worsen: 2

• Increase oral mesalamine dose to 4.8 g/day 2
• Continue treatment for up to 40 days before determining failure, as sustained remission may take time 2

If inadequate response to optimized mesalamine after 40 days: 2

• Add oral prednisolone 40 mg daily with tapering over 6-8 weeks 1, 2
• Alternatively, consider budesonide MMX 9 mg/day for left-sided disease as it has fewer systemic side effects than conventional steroids 1, 2

Maintenance Therapy

After achieving remission, continue lifelong maintenance therapy with mesalamine to prevent relapse 3, 2

• This is especially critical for patients with left-sided or extensive disease 3
• Maintenance therapy may reduce the risk of colorectal cancer 3
• Discontinuation may be reasonable only for distal disease in remission for 2 years in patients averse to medication 3

Critical Monitoring and Safety Considerations

Monitor renal function regularly: 2

• Check eGFR before starting mesalamine, after 2-3 months, and then annually 2
• Mesalamine may decrease renal function, especially in patients with known renal impairment or taking nephrotoxic drugs 4

Avoid rapid corticosteroid tapers: 1

• Taper prednisolone gradually over 8 weeks to prevent early relapse 1
• Single daily dosing of prednisolone is as effective as split-dosing and causes less adrenal suppression 2

Common Pitfalls to Avoid

• Do not use oral mesalamine alone for left-sided or extensive disease—combination with topical therapy is significantly more effective 1, 2
• Do not escalate to biologics or immunosuppressants before optimizing mesalamine therapy for 40 days unless severe disease is present 2
• Do not use topical corticosteroids as first-line for proctitis—topical mesalamine is more effective 1
• Do not continue long-term corticosteroids—they are for induction only, not maintenance, due to significant side effects 2