Objectives: To determine the long term outcome of ulcerative colitis in patients treated with 6-MP.
Methods: The charts of 105 chronic refractory ulcerative colitis patients treated with 6-MP from 1973-1992 were reviewed. The focus was placed on clinical response, subsequent breakthrough while maintaining 6-MP, and relapse rates when 6-MP was discontinued.
Results: Complete clinical remission was achieved in 68 patients (65%), partial remission was achieved in 25 patients (24%), and 12 patients (11%) failed to achieve remission. Of complete responders who continued 6-MP, 35% had a breakthrough, although complete remission was restored in 88% with the majority not requiring systemic steroids. Of complete responders who discontinued 6-MP, 87% subsequently relapsed. There were few major toxicities associated with 6-MP use.
Conclusion: 6-MP is a reasonably safe and effective treatment for refractory ulcerative colitis. Patients who discontinue 6-MP after successful treatment have high relapse rates, therefore, 6-MP must be maintained long term to sustain remission.