Dexamethasone is a synthetic corticosteroid, a man-made version of the hormones produced by the adrenal glands. It is a powerful anti-inflammatory and immune-suppressing medicine used across many areas of medicine.
What It Is
Dexamethasone belongs to a class of medicines called corticosteroids, often simply called steroids. It is a long-acting member of this class and is stronger than commonly used steroids such as prednisolone. It is available as tablets, injections, eye drops, ear drops, and other forms.
What It's Used For
Dexamethasone is generally used to reduce inflammation and calm an overactive immune system. It is commonly used for severe allergic reactions, asthma and COPD flare-ups, swelling around brain tumours, and certain autoimmune conditions. It is also used to prevent nausea and vomiting during chemotherapy, to treat eye inflammation, and in patients with severe COVID-19 who need oxygen or ventilation. In pregnancy, it may be given when early delivery is expected, to help the baby's lungs mature.
How It Works
Dexamethasone works by binding to glucocorticoid receptors inside cells, which changes how genes are switched on and off. This reduces the production of inflammatory chemicals such as cytokines and prostaglandins and lowers the activity of immune cells. The result is less swelling, redness, and allergic response. Its effects last longer than those of prednisolone, and it causes very little salt and water retention, which distinguishes it from some other steroids.
History and Regulatory Status
Dexamethasone was developed in the 1950s as part of the search for stronger and more targeted steroid medicines, and it has been in medical use since the late 1950s. It became widely known again in 2020, when large trials showed that it reduced deaths in patients with severe COVID-19. It is available as a generic medicine under many brand names and is included on the World Health Organization's list of essential medicines. In most countries, including India, it is a prescription-only medicine.