There are many side effects associated with prednisone, but most of them occur with dosages above 10 mg, according to Drugs.com. Adverse effects are divided according to those linked with short-term or long-term prednisone use. Steroids such as prednisone suppress the immune system, and their actions mimic natural corticosteroids produced by the adrenal glands. Long-term prednisone therapy must be discontinued gradually so the body can resume producing cortisol.
Short-term effects include weight gain, fluid retention, hyperglycemia, depression and mood changes ranging from mild to severe. Long-term side effects include Cushing syndrome (from too much cortisol), excess hair, male secondary sexual traits in females, impotence, menstrual irregularities, peptic ulcers, cataracts, glaucoma, myopathy, osteoporosis, and vertebral compression fractures. Prednisone can have metabolic side effects such as hypokalemia or low blood potassium levels that affect the heart. Prednisone has been implicated in cardiovascular dysfunction. There are endocrinal side effects, such as glucose intolerance, and gastrointestinal symptoms, such as nausea or vomiting.
Corticosteroids inhibit the absorption of calcium and lead to osteoporosis and bone loss. One-third of kidney transplant patients on a daily dose of 10 mg prednisone develop cataracts. Patients taking 10 mg prednisone daily had 50 percent fewer infections than patients taking an average of 20 mg daily, according to Drugs.com.