Efficacy and safety of 6-thioguanine in the management of inflammatory bowel disease.
OBJECTIVE
6-Thioguanine has been used as an alternative immunomodulator in the treatment of inflammatory bowel disease but data on its efficacy and safety are limited. The aim of this study was to analyse our experience of the efficacy and safety of 6-thioguanine in inflammatory bowel disease.


METHODS
Patients attending the inflammatory bowel disease clinic who were started on 6-thioguanine therapy were included in this prospective observational study. Indications for initiating 6-thioguanine therapy and other related clinical, pharmacological and laboratory parameters prior to and during therapy were recorded to determine the efficacy and safety of 6-thioguanine.


RESULTS
A total of 40 patients were treated with 6-thioguanine, 28 with Crohn's disease, 10 with ulcerative colitis and 2 with indeterminate colitis, at a fixed daily dose of 40 mg and continued for a median duration of 34 weeks (range 2-90 weeks). The indications for 6-thioguanine therapy included previous clinical resistance to thiopurine analogues (n=21), intolerance to thiopurine analogues (n=8) and de novo 6-thioguanine use in steroid refractory disease (n=11). Disease remission was reached in 44%, 73% and 89% of these patient groups at 3, 6 and 12 months, respectively. Inflammatory markers and steroid use were significantly lower during 6-thioguanine therapy compared with in the period before therapy. Therapy was discontinued in 13 patients (33%), mainly because of thrombocytopenia and associated hepatotoxicity.


CONCLUSIONS
6-Thioguanine is a useful addition to treatment in inflammatory bowel disease but the frequent occurrence of hepatotoxicity limits its routine use.
Qasim
Asghar
A
Adelaide and Meath Hospital, Tallaght, Trinity College, Dublin, 24, Ireland.
McDonald
Sharon
S
Sebastian
Shaji
S
McLoughlin
Ramona
R
Buckley
Martin
M
O'Connor
Humphrey
H
O'Morain
Colm
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012074:Remission Induction; D013866:Thioguanine / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome
D000964:Antimetabolites, Antineoplastic; D013866:Thioguanine