Immunosuppressants

Immunosuppressive (IS) therapies play a prominent role in treating chronic inflammatory conditions of the gastrointestinal (GI) tract. IS therapies have significantly expanded in recent decades, resulting in an increasingly wide range of therapeutic options. Older, non-selective agents are still commonly used in clinical practice, although the development of numerous targeted therapies has further enhanced treatment options. With the growing number of therapies, understanding the pharmacology and pharmacokinetics of IS therapies is essential in guiding treatment decisions and drug monitoring, avoiding drug interactions and minimizing adverse reactions. In this article, we summarize relevant information pertaining to common categories of IS therapies used to treat GI conditions, including (i) Corticosteroids; (ii) Calcineurin inhibitors; (iii) Antimetabolites and Antiproliferative agents; (iv) Biologic Targeted Therapies; and (v) Non-biologic targeted therapies. We review each of these categories using a structured format, comprising: (i) Mechanism of Action; (ii) Dosing; (iii) Pharmacokinetics; (iv) Adverse effects; (v) Drug interactions; and (vi) Place in therapy/therapeutic considerations. The latter relates to the practical application of IS agents to treat inflammatory bowel diseases (IBD) and to prevent and/or treat liver transplant rejection. Detailed review of the evidence base for use of these agents in GI conditions is outside the scope of this article. We also offer a brief overview of Future Therapies and Current Developments with regards to upcoming IS therapies.