Corticosteroids are the strongest drugs available for reducing inflammation in the body. They are useful in any condition in which inflammation occurs, including rheumatoid arthritis and other connective tissue disorders, multiple sclerosis, and in emergencies such as brain swelling due to cancer, asthma attacks, and severe allergic reactions. When inflammation is severe, use of these drugs is often lifesaving.

Corticosteroids can be

• Given by vein (intravenously—especially in emergency situations)

• Taken by mouth (orally)

• Directly applied to the inflamed area (topically; for example, as eye drops or as skin creams)

• Inhaled (as in inhaled versions for the lungs, used to treat disorders such as asthma and COPD)

• Injected into a muscle (intramuscularly)

• Injected into a joint

For example, corticosteroids can be used as an inhaled preparation for treatment of asthma. They can be used as a nasal spray to treat hay fever (allergic rhinitis). They can be used as eye drops to treat eye inflammation (uveitis). They may be applied directly to an affected area for treatment of certain skin conditions such as eczema and psoriasis. They can be injected into joints inflamed by rheumatoid arthritis or another disorder.

Corticosteroids are prepared synthetically to have the same action as cortisolcortisol

Corticosteroids reduce the body’s ability to fight infections by reducing inflammation, typically when they are taken by mouth or given by vein. Because of this side effect, they are used with extreme care when infections are present. Oral and intravenous use may cause or worsen high blood pressure, heart failure, diabetes, peptic ulcers, and osteoporosis. Therefore, corticosteroids are used in such conditions only when their benefit is likely to exceed their risk.

When they are taken by mouth or by injection for more than about 2 weeks, corticosteroids should not be stopped abruptly. This is because corticosteroids inhibit the production of cortisol by the adrenal glands, and this production must be given time to recover. Thus, at the end of a course of corticosteroids, the dose is gradually reduced. It is important for a person who takes corticosteroids to follow the doctor’s instructions on dosage very carefully.

The long-term use of corticosteroids, particularly at higher doses and particularly when given by mouth or vein, invariably leads to many side effects, involving almost every organ in the body. Common side effects include thinning of the skin with stretch marks and bruising, high blood pressure, elevated blood sugar levels, cataracts, puffiness in the face (moon face) and abdomen, thinning of the arms and legs, poor wound healing, stunted growth in children, loss of calcium from the bones (which can lead to osteoporosis), hunger, weight gain, and mood swings. Inhaled corticosteroids and corticosteroids that are applied directly to the skin have far fewer side effects than corticosteroids given by mouth, vein, or injection.