The most common Imuran® side effects are nausea, vomiting, and loss of appetite. There are many other, less common side effects also associated with the drug, such as fatigue, joint pain, diarrhea and hair loss. Interactions with other drugs might produce undesirable side effects as well. For example, when Imuran® is taken with allopurinol, it can increase the risk of side effects, and when taken with angiotensin-converting enzyme (ACE) inhibitors, Imuran® it can induce anemia.

Imuran® is a brand name for azathioprine, which is an immunosuppressant drug. Immunosuppressant drugs suppress the production of T and B lymphocytes, which are two types of white blood cells. The common Imuran® side effects are nausea and vomiting. These can be coupled with a loss of appetite. These side effects are generally not considered to be indicative of a problem unless they are especially persistent or unmanageable.

This drug is commonly administered to patients who have undergone a kidney transplant or have a condition that affects the immune system. Imuran® is available in the form of pills or as an injection, and is administered in doses of 25, 50 and 100 milligrams. It is available only through a prescription. Imuran® should never be prescribed with ACE inhibitors, warfarin or allopurinol, because it has been known to produce reactions when combined with these drugs. When taken with warfarin, Imuran® can reduce its blood-thinning effects.

The less common Imuran® side effects are much more serious in nature, and anybody experiencing them is advised to contact his or her doctor. These side effects might include fatigue, joint pain, dark urine, fever and pale stools. They also can include shortness of breath, unusual bleeding, unusual growths, hair loss and yellowing skin or eyes. Although these are not the most common Imuran® side effects, they should be watched for in anybody taking the drug.

As well as the common Imuran® side effects listed, there also is the risk of an allergic reaction when taking the drug. This risk exists with many medications and might manifest itself as a rash, itchiness, hives, swelling of the face or tightness in the chest. These are serious side effects, and anybody experiencing them should contact his or her doctor. Any one of the more serious side effects occurring could be cause to stop taking Imuran®.