Low dose thioguanine guided by therapeutic drug monitoring is a safe and effective alternative in inflammatory bowel disease patients intolerant to conventional thiopurines.

Thioguanine was tolerated well in 63% of patients. Clinical response was seen in 62 % of and maintenance of remission was high at 76 %. No cases of early NRH were seen. Longer-term follow-up is required to ensure safety and to assess durability of response. This article is protected by copyright. All rights reserved.