There are a number of drugs used to control inflammatory bowel disease symptoms. The most common IBD treatments fall into several categories: anti-inflammatory sulfa drugs, steroidal anti-inflammatory drugs, immune system suppressor drugs and antibiotics.
Common IBD Treatments
Anti-inflammatory sulfa drugs
Anti-inflammatory sulfa drugs are based on antibacterial sulfonamides and were first developed for rheumatoid arthritis patients. It was thought that bacterial infections were the main cause in the rheumatoid arthritis. Nowadays, the antibacterial mechanism of this class of drugs is secondary to their ability to lower the production of inflammatory mediators, like cytokines and eicosanoids. All of these drugs are designed to deliver the active component, 5-aminosalicylic acid (5-ASA) to the intestines.
- Sulfasalazine (Azulfidine®)
- Mesalamine (Apriso®, Asacol®, Lialda®)
- Balsalazide (Colazal®)
- Olsalazine (Dipentum®)
Steroidal anti-inflammatory drugs
Steroidal anti-inflammatory drugs are forms of corticosteroids. These drugs mimic naturally produced hormones from the adrenal gland. The adrenal gland is responsible for producing hormones in response to stress. There are a variety of corticosteroids produced by the adrenal gland, and the one of the most useful against inflammation is glucocorticoid. This molecule binds to the glucocorticoid receptor (GR) and leads to the up-regulation of anti-inflammatory mediators.
- Budesonide (Entocort®)
- Hydrocortisone (Cortef®, Proctofoam-HC®)
- Prednisolone (Orapred ODT®)
Immune suppressor drugs
Immune system suppressor drugs are designed to limit the effects of the immune system. In this category are several types of drugs.
- Purine analogues
Purine analogues: One of the most widely used types of drugs for the treatment of IBD is the purine analogues. Purines are a class of molecules to which the nucleotides adenine and guanine belong. By interfering with the enzymes needed to extend DNA, the purine analogues disrupt DNA synthesis. When this happens, the proliferation of immune cells (such as T and B cells) is reduced.
- Azathioprine (Azasan®, Imuran®)
- Mercaptopurine (Purinethol®)
Cyclosporine: Purine analogues are not the only way to interfere with T cells. Cyclosporine was found in the fungus Tolypocladium inflatum and has the same property. Cyclosporine is capable of inhibiting the mechanisms that lead to IL-2 transcription. IL-2 is a cytokine that is produced upon T cell activation and is needed, in an autocrine fashion, for robust proliferation and survival. Cyclosporine is produced under a number of trade names including:
Neutralizing antibodies: The most modern type of immune system suppressor drugs used for IBD is the biologicals (also called neutralizing antibodies.) These drugs take advantage of both the technology to produce specific antibodies and the knowledge of drug targets in the immune system. The first three of these drugs listed are targeted against tumor necrosis factor α (TNFα). TNFα is a potent cytokine that supports inflammation. Natalizumab is targeted against a cell adhesion molecule, α4-integrin, that is used for T cell migration to sites of inflammation.
The gut is home to a large range of microbiota and these inhabitants can be de-regulated in IBD patients. Antibiotics are known to decrease microbial load and composition. Furthermore, they are effective in treating tissue invasive bacteria and bacteria that are located throughout the body (systemically disseminated).
In UC, surgery can often eliminate ulcerative colitis when either the inflamed area of the colon or the entire colon and rectum (proctocolectomy) is removed . After surgery, fecal material is collected in an exterior bag connected to an opening in the abdomen (ileostomy). A newer, preferred procedure called, ileoanal anastomosis, eliminates the need for a bag by constructing a pouch from tissues at the end of the small intestine, which then connects to the anus. In CD, surgery is used to remove diseased sections of the digestive tract. It is less successful as the disease often reoccurs in the remaining un-inflamed regions of colon tissue. As CD patients often have fistulas or abscesses, surgery can be applied to help them heal and close. Another common procedure for Crohn’s is strictureplasty, which widens a segment of the intestine that has become too narrow.
Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment.
- Staff. 2012. Mayo Clinic. Ulcerative colitis – Treatments and drugs.
- Staff. 2012. Mayo Clinic. Crohn’s disease – Treatments and drugs.
- Triantafillidis, J. K., E. Merikas, and F. Georgopoulos. 2011. Current and emerging drugs for the treatment of inflammatory bowel disease. Drug Des Devel Ther 5:185-210.