Monitoring and management of toxicities in long-term thiopurine therapy.

KK Thiopurines are slow-acting drugs, taking up to 6 months to reach a therapeutic effect. They can be used by themselves as monotherapy or in combination with other therapies. If they are tolerated as monotherapy and if remission of inflammatory bowel disease (IBD) is achieved, then they are good choices for long-term maintenance therapy. Studies have shown that discontinuing therapy results in relapse even up to 5 years after initiation of therapy. There is no compelling evidence to discontinue thiopurine therapy if the patient is doing well, and there also is no compelling evidence to reduce the dose to avoid toxicity.