Beneficial and Harmful Effects of Azathioprine and Allopurinol Versus Standard Azathioprine Therapy for Patients With Ulcerative Colitis
Beneficial and Harmful Effects of Azathioprine and Allopurinol Versus Standard Azathioprine Therapy for Patients With Ulcerative Colitis
Azathioprine is considered first line immunomodulatory therapy for patients with ulcerative
 colitis. Up to 50% are treatment failures or experience adverse events leading to treatment
 withdrawal. Recent evidence suggests that the combination of allopurinol and low dose
 azathioprine increases the proportion of treatment responders and reduce the risk of adverse
 events.

 Objectives: To evaluate the beneficial and harmful effects of low dose azathioprine and
 allopurinol versus standard azathioprine monotherapy in patients with ulcerative colitis.
Investigator initiated, multicentre, parallel arm, open, randomised controlled trial with
 blinded assessment
Inclusion Criteria:

 -  Willingness to comply with all trial procedures and being available for the duration
 of the trial.

 -  Clinically and histologically verified ulcerative colitis eligible for treatment with
 thiopurines due to steroid dependence (failure to taper steroid or starting a second
 course of systemic steroids within 1 year) or patients with the need for rescue
 therapy with anti-TumorNecrosisFactorα (anti-TNFα)

 -  A sigmoidoscopy or colonoscopy showing active inflammation during the present disease
 flare

 -  Negative stool test for pathogen bacteria incl. Clostridium difficile

 -  Informed consent.

 -  Normal TPMT genotype (homozygous wild-type).

 -  Oral 5-Asa dose stable for 2 weeks

 Exclusion Criteria:

 -  Kidney disease with a GlomerularFiltration Rate (GFR) < 50 ml/min.

 -  Persistent alanine aminotransferase U/L (ALT) twice above upper limit of the normal
 range.

 -  Participation in other interventional clinical trials.

 -  Pregnancy or breastfeeding.

 -  Previous thiopurin treatment.

 -  Previous or current treatment with other biologics than anti-TNFα

 -  Not being able to comply with the study, assessed by investigator