Betamethasone

Betamethasone is a potent synthetic glucocorticoid corticosteroid with anti-inflammatory and immunosuppressive properties. It is available in several forms and esters for different routes of administration. Topical preparations such as betamethasone valerate and betamethasone dipropionate are used for inflammatory skin conditions, while injectable forms, including betamethasone sodium phosphate and betamethasone acetate, are used for systemic therapy. Betamethasone is also used in obstetric care to accelerate fetal lung maturation in pregnancies at risk of preterm birth, typically given as two intramuscular injections of 12 mg each 24 hours apart. Ophthalmic preparations of betamethasone exist for inflammatory eye conditions.

Mechanism of action involves binding to the glucocorticoid receptor, leading to changes in gene expression that decrease the production of inflammatory mediators, suppress immune responses, and reduce edema and immune cell activity.

Common medical uses include dermatologic disorders such as eczema, psoriasis, and dermatitis; inflammatory and allergic conditions in various organ systems; and, in obstetrics, prevention of neonatal respiratory distress syndrome. Ophthalmic uses address inflammatory conditions of the eye, while systemic forms treat widespread inflammation or immune-mediated diseases when topical or local therapy is insufficient.

Adverse effects depend on the route and potency. Topical high-potency betamethasone can cause skin thinning, stretch marks, telangiectasia, and pigment changes. Systemic corticosteroid exposure may lead to hypothalamic-pituitary-adrenal axis suppression, growth retardation in children, weight gain, hypertension, hyperglycemia, osteoporosis, and increased infection risk. Prolonged ophthalmic use may raise intraocular pressure and contribute to cataract formation.

Contraindications include systemic fungal infections and hypersensitivity. Caution is advised during pregnancy and lactation, in infections, diabetes, osteoporosis, and in children. Drug interactions may affect glucose tolerance, infection risk, or wound healing, and concurrent live vaccines may be diminished in effectiveness.