What are Corticosteroids?
Corticosteroids belong to a group of naturally-occurring steroid hormones that are produced in the adrenal gland. This is the small gland that is located on top of each kidney and consists of an outer layer called the cortex and the inner core known as the medulla. The cortex of the adrenal gland is responsible for natural corticosteroid secretion.
Synthetic corticosteroids are used topically in creams or systemically as oral drugs. These corticosteroids are used to treat a wide range of diseases. When used in high doses or for prolonged periods of time, corticosteroids can have a number of adverse effects.
The corticosteroids primarily fall into 2 groups namely :
- glucocorticoids like cortisol
- mineralocorticoids like aldosterone
Glucocorticoids are involved in a wide range of actions in the body such as regulation of the immune response and anti-inflammatory reactions, as well as regulation of carbohydrate, fat and protein metabolism. Mineralocorticoids are responsible for maintaining salt and water balance in the body.
The clinically used glucocorticoids are either natural (hydrocortisone or cortisol) or synthetic (prednisone, prednisolone, betamethasone, beclomethasone, triamcinolone, dexamethasone, fluticasone, budesonide ). Some of these glucocorticoids like hydrocortisone, prednisone have salt retaining action like the mineralocorticoids. The clinically used mineralocorticoid is a synthetic derivative called fludrocortisone.
Benefits of Corticosteroids
Corticosteroids are used for replacement therapy in patients with corticosteroid deficiency. It is also used clinically for a wide range of diseases. Glucocorticoids may be used for the following :
- allergic diseases – allergic rhinitis, anaphylaxis
- autoimmune diseases – systemic lupus erythematosus (SLE)
- rheumatic disorders – rheumatoid arthritis
- prevent the rejection of transplants
- certain cancers like lymphoma
- edema of brain
- certain infections like meningitis, septic shock
- respiratory diseases like bronchial asthma
- skin diseases like atopic dermatitis, urticaria
The beneficial effects obtained from use of the corticosteroids vary considerably. Use of corticosteroids are assessed in each patient against the widespread effects on various parts of the body. When glucocorticoids are used for short periods (less than 2 weeks), it is unusual to see serious adverse effects even with moderately large doses.
Side Effects of Corticosteroid Use
The major side effect of the prolonged glucocorticoid therapy (> 2 weeks) is the result of their excessive hormonal actions, which lead to conditions like Cushing’s syndrome. It causes muscle weakness and wasting, osteoporosis, and increases risk of diabetes, hypertension, peptic ulcer and cataract. It can also increase susceptibility to infections due to its immunosuppressive action. Corticosteroid use may also retard growth in children and cause behavioral changes like restlessness, changes in mood and psyche.
Stopping Corticosteroid Therapy
When the glucocorticoids are used for long periods (greater than 2 weeks) in moderate to large doses, it leads to the suppression of corticosteroid secretion from within the body. In these instances, if the corticosteroid treatment is stopped abruptly, it will lead to acute corticosteroid deficiency.
Corticosteroid treatment should be reduced gradually over a period of a few weeks to prevent the withdrawal effects. Stopping corticosteroids can also cause acute flare up of the underlying disease for which the drug was prescribed. Always speak to a doctor before reducing the dosage or stopping corticosteroids altogether.
Cushing’s Syndrome from Corticosteroids
Prolonged use of therapeutic corticosteroids will affect the body in a number of ways. Increase in the levels of synthetic corticosteroids as well as reduction of natural levels in the body can lead to a condition known as Cushing’s syndrome. It is characterized by :
- round moon-like face
- obesity of the trunk
- buffalo hump – fat deposition at back of neck forming a hump
- skin pigmentation
- weight gain
- hirsutism – facial hair growth in females
- purple striae on the abdomen and thigh
- osteoporosis (weak fragile bones)
- mental/emotional features such as restlessness, depression, decreased libido, insomnia, and anxiety
The decreased levels of corticoidsteroids chronically can manifest as weakness, fatigue, weight loss, hypotension, hyperpigmentation, and inability to maintain the blood glucose level during fasting. An acute drop is a medical emergency.