The immune system plays a key role in IBD. It’s the immune system that creates inflammation in the gut, and over time this inflammation causes injury to the intestinal tissue. It’s not fully understood *WHY* this happens, though many different schools of thought converge on the possibility that the immune system determines that flora in the gut are invasive and harmful, and in turn uses inflammation to make the gut less hospitable. This is the stuff another post. Suffice it to say for now that one effective and common treatment for achieving and maintaining Crohn’s remission is the use of medication to suppress the immune system, thereby suppressing the inflammation it can create.
There are two primary groups of immunosuppressants used in the treatment of Crohn’s, one group takes longer to take effect, but is less suppressive of immunity, while the other is quicker-acting, but suppresses the immune system more completely.
Common medications in the first group are azathioprine and 6-mercaptopurine (or 6-MP). These drugs aren’t fast-acting or powerful enough for quieting active flares and achieving remission, but they can be effective for maintaining remission of both kinds of IBD. Because of their slow onset (3-6 months!), patients who are actively flaring will often begin taking one of these along with a more aggressive medication, like steroids, allowing the patient to begin the onset period while quieting the current flare. These drugs are administered orally. So far, this is the only type of immunosuppressant that my MD has discussed with me.
More aggressive immunosuppressants are available. Cyclosporine A and tacrolimus take effect much more quickly (1-2 weeks), and suppress the immune system to such a degree that, in patients who are not responsive to steroids, they can be used to achieve remission from active flare. These drugs can be administered orally, or if more immediate and powerful effect is required, intravenously. These medications are the same ones used by organ transplant recipients to prevent rejection of their new organs. My MD did not discuss this class of drug with me. I’m assuming that he didn’t feel it was necessary, given that I’m not actively flaring right now (or if I am, then it’s the same kind of ninja flare that got me into this mess in the first place!).
Methotrexate is another immunosuppressant sometimes used to treat Crohn’s (but not UC). It’s generally only administered by weekly injection to patients who aren’t responsive to the other options.
It should be obvious that there’s a major downside to suppressing the immune system: It can no longer do its job very effectively, and when the immune system can’t create immunity, one is likely to get sick a lot. There are a variety of other symptoms that show up with medications like this, including:
- diarrhea (just what an IBD patient needs, right?!)
- canker sores
- liver damage
- high blood pressure
- increased risk of lymphoma
I feel similarly cautious toward these drugs as I do toward steroids. I think of them as ‘big guns’. I would take them if I needed to, but I’d STRONGLY prefer to avoid them if at all possible. Obviously, as I’ve discussed previously, there will be no decisions regarding medications until we get test results back in mid-October. If those results come back and the MD wants to put me on azathioprine, he’s going to have to work hard sell me on it before I’ll agree. I’m deeply skeptical of changing my biochemistry and altering the function of such a core system, and have some belief that, like steroids, it’s likely to create as many problems as it solves.
I’ll be traveling this holiday weekend, so it may be a few days before I get around to posting on the role of antibiotics in Crohn’s treatment.