Prednisone, especially when taken long term, can cause a wide range of serious side effects, including diabetes, thinning bones (osteoporosis), broken bones (osteonecrosis), high blood pressure, cataracts, glaucoma
and weight gain.
Azathioprine (Azasan, Imuran). Azathioprine, another immunosuppressant medication, is sometimes used along with prednisone. Using both medications may allow you to take a smaller dose of prednisone, reducing its side effects.