23740
PURPOSE : Recent studies in patients with inflammatory bowel diseases ( IBD ) on thiopurine therapy suggest that too low 6 - thioguanine nucleotide concentrations ( 6 - TGN ) and too high methylmercaptopurine nucleotide concentrations ( MMPN ) can be reversed by a combination therapy of allopurinol and low - dose thiopurines .
 Chemical: thiopurine; Chemical: 6 - thioguanine nucleotide; Chemical: 6 - TGN; Chemical: methylmercaptopurine nucleotide; Chemical: MMPN; Chemical: allopurinol; Chemical: thiopurines
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: thiopurine; Chemical: 6 - thioguanine nucleotide; Chemical: 6 - TGN; Chemical: methylmercaptopurine nucleotide; Chemical: MMPN; Chemical: allopurinol; Chemical: thiopurines