Side Effects. See also Warning section. Nausea or vomiting may occur. Taking this medication after meals may help lessen these effects. Temporary hair loss may also occur. Our Imuran (azathioprine) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication. This is not a complete list of side effects and others may occur. What form(s) does this medication come in? Each pale yellow, peanut-shaped tablet, scored and engraved AZ 50 on one side and plain on the other, contains 50 mg of azathioprine. Consumer information about the medication AZATHIOPRINE - ORAL (Imuran), includes side effects, drug interactions, recommended dosages, and storage information. Read more about the prescription drug AZATHIOPRINE - ORAL. It is an imidazolyl derivative of 6-mercaptopurine and many of its biological effects are similar to those of the parent compound. Azathioprine, USP is a pale yellow, odorless powder. DESCRIPTION. IMURAN (azathioprine), an immunosuppressive antimetabolite, is available in tablet form for oral administration. Each scored tablet contains 50 mg azathioprine and the inactive ingredients lactose, magnesium stearate, potato starch, povidone, and stearic acid. Side Effects. See also Warning section. Nausea or vomiting may occur. Taking this medication after meals may help lessen these effects. Temporary hair loss may also occur. You may report side effects to FDA at 1-800-FDA-1088. What is the most important information I should know about azathioprine (Azasan, Imuran)? Some people using azathioprine have developed a rare fast-growing type of lymphoma (cancer). Commonly reported side effects of azathioprine include: infection, nausea, leukopenia, and vomiting. See below for a comprehensive list of adverse effects. See below for a comprehensive list of adverse effects. Side Effects. Drug information provided by: IBM Micromedex. Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.