Microscopic colitis is a common chronic diarrheal disease, and remission can be induced with budesonide.
However, diarrhea relapses frequently when budesonide is tapered, and a few patients become budesonide intolerant.
Dr Münch and colleagues examined retrospectively the effect of azathioprine and mercaptopurine in patients with chronic, active microscopic colitis.
Data on all microscopic colitis patients who received azathioprine or mercaptopurine in the years 1997–2011 at 3 centers representing 3 countries were pooled for analysis.
Indications for thiopurine therapy were frequent relapses after short-term treatment, budesonide dependency on 6 mg and budesonide intolerance.
The response to thiopurine treatment was defined as clinical remission, intolerance or nonresponse.
The research team evaluated 46 microscopic colitis patients, of which 32 were female, with median age 59 years with a median disease duration of 3 years.
The researchers found that 13 patients achieved long-term clinical remission on azathioprine therapy.
The doctors reported that azathioprine failed in 31 patients due to intolerance, and in 2 patients because of nonresponse.
|The calculated pooled gastric cancer incidence-rate was about 0.3% per person-years|
|Alimentary Pharmacology & Therapeutics|
The team observed that 13 of 31 azathioprine -intolerant patients were switched to mercaptopurine, and 6 patients obtained clinical remission.
Thus, the overall response rate to thiopurines was 19 out of 46.
The researchers assessed that the main side effects were nausea/vomiting and abnormally elevated liver enzymes.
Dr Münch's team concludes, "In this retrospective case series, the majority of chronic, active microscopic colitis patients were intolerant to azathioprine leading to cessation of treatment."
"However, further studies are needed to explore the efficacy, acceptance, tolerance and safety of mercaptopurine in patients with chronic, active Microscopic colitis refractory to budesonide."