Efficacy of thioguanine treatment in inflammatory bowel disease: A systematic review.
OBJECTIVE
To critically assess the available literature regarding the efficacy of thioguanine treatment in inflammatory bowel disease (IBD) patients, irrespective of the (hepato-) toxicity profile.


METHODS
A systematic literature search of the MEDLINE database using PubMed was performed using the keywords "thioguanine", "6-TG", "thioguanine", "inflammatory bowel disease", "IBD", "Crohn's disease", "Ulcerative colitis" and "effectiveness" in order to identify relevant articles published in English starting from 2000. Reference lists of the included articles were cross-checked for missing articles. Reviewed manuscripts concerning the effectiveness of thioguanine treatment in IBD were reviewed by the authors and the data were extracted. Data were subsequently analyzed with descriptive statistics. Due to the lack of standardized outcomes, a formal meta-analysis was not performed.


RESULTS
A total of 11 applicable studies were found that involved the effectiveness of thioguanine therapy in IBD. Eight studies were conducted in a prospective manner, in the remaining three studies, data was collected retrospectively. In total, 353 IBD-patients (225 patients with Crohn's disease, 119 with ulcerative colitis and nine with unclassified IBD) with prior azathioprine/mercaptopurine resistance and/or intolerance (n= 321) orde novothioguanine administration (n= 32) were included for analysis, of which 228 (65%) had clinical improvement on thioguanine therapy, based on standard IBD questionnaires, biochemical parameters or global physician assessments. Short-term results were based on 268 treatment years (median follow-up 9 mo, range 3-22 mo) with a median daily dose of 20 mg (range 10-80 mg). Discontinuation, mostly due to adverse events, was reported in 72 patients (20%).


CONCLUSIONS
The efficacy of thioguanine therapy in IBD patients intolerant to conventional thiopurine therapy is observed in 65%, with short term adverse events in 20% of patients.
Berrie Meijer, Chris JJ Mulder, Adriaan A van Bodegraven and Nanne KH de Boer, Department of Gastroenterology and Hepatology, VU University Medical Center, 1081 HV Amsterdam, The Netherlands.
Berrie
B
Meijer
Berrie Meijer, Chris JJ Mulder, Adriaan A van Bodegraven and Nanne KH de Boer, Department of Gastroenterology and Hepatology, VU University Medical Center, 1081 HV Amsterdam, The Netherlands.
Chris Jj
CJ
Mulder
Berrie Meijer, Chris JJ Mulder, Adriaan A van Bodegraven and Nanne KH de Boer, Department of Gastroenterology and Hepatology, VU University Medical Center, 1081 HV Amsterdam, The Netherlands.
Godefridus J
GJ
Peters
Berrie Meijer, Chris JJ Mulder, Adriaan A van Bodegraven and Nanne KH de Boer, Department of Gastroenterology and Hepatology, VU University Medical Center, 1081 HV Amsterdam, The Netherlands.
Adriaan A
AA
van Bodegraven
Berrie Meijer, Chris JJ Mulder, Adriaan A van Bodegraven and Nanne KH de Boer, Department of Gastroenterology and Hepatology, VU University Medical Center, 1081 HV Amsterdam, The Netherlands.
Nanne Kh
NK
de Boer
D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use*; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy*; D013866:Thioguanine / Q000627:therapeutic use*
D000964:Antimetabolites, Antineoplastic; D013866:Thioguanine
Crohn’s disease; Inflammatory bowel disease; Thioguanine; Thiopurines; Ulcerative colitis