It's dexamethasone, an oral (cortico)steroid. Despite the lengthy side effects and interactions sections below, this is a very safe and effective medication for short term use in most patients.
PRESCRIBED FOR: Dexamethasone is used to achieve prompt suppression of inflammation in many conditions. Some examples include rheumatoid arthritis, systemic lupus, acute gouty arthritis, psoriatic arthritis, ulcerative colitis, and Crohn's disease. Severe allergic conditions that fail conventional treatment may also respond to dexamethasone. Examples include bronchial asthma, allergic rhinitis, drug-induced dermatitis, and contact and atopic dermatitis. Chronic skin conditions treated with dexamethasone include dermatitis herpetiformis, pemphigus, severe psoriasis and severe seborrheic dermatitis. Chronic allergic and inflammatory conditions of the uvea, iris, conjunctiva and optic nerves of the eyes are also treated with dexamethasone.
Dexamethasone is also used in the treatment of blood cell cancers (leukemias), and lymph gland cancers (lymphomas). Blood diseases involving destruction of platelets by the body's own immune cells (idiopathic thrombocytopenia purpura), and destruction of red blood cells by immune cells (autoimmune hemolytic anemia) can also be treated with dexamethasone. Other miscellaneous conditions treated with this medication include thyroiditis and sarcoidosis. Finally, dexamethasone is used as a hormone replacement in patients whose adrenal glands are unable to produce sufficient amounts of corticosteroids."
SIDE EFFECTS: Dexamethasone side effects depend on the dose, the duration and the frequency of administration. Short courses of dexamethasone are usually well tolerated with few and mild side effects. Long term, high doses of dexamethasone will usually produce predictable, and potentially serious side effects. Whenever possible, the lowest effective doses of dexamethasone should be used for the shortest possible length of time to minimize side effects. Alternate day dosing can also help reduce side effects.
Side effects of dexamethasone and other corticosteroids range from mild annoyances to serious irreversible bodily damages. Side effects include fluid retention, weight gain, high blood pressure, potassium loss, headache, muscle weakness, puffiness of and hair growth on the face, thinning and easy bruising of skin, glaucoma, cataracts, peptic ulceration, worsening of diabetes, irregular menses, growth retardation in children, convulsions, and psychic disturbances. Psychic disturbances can include depression, euphoria, insomnia, mood swings, personality changes, and even psychotic behavior.