23751
CONCLUSIONS : Combination therapy with only 50 mg allopurinol and 50 mg azathioprine daily is sufficient , efficacious and safe in most IBD patients with inadequate thiopurine metabolite concentrations to optimize azathioprine - based IBD therapy .
 Chemical: allopurinol; Chemical: azathioprine; Chemical: thiopurine; Chemical: azathioprine
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: allopurinol; Chemical: azathioprine; Chemical: thiopurine; Chemical: azathioprine