| Indication | Injection: for the treatment of endocrine disorders,
rheumatic D=disorders, collagen diseases, dermatologic diseases,
allergic statesc, ophthalmic diseases, gastrointestinal diseases,
respiratory diseases, hematologic disorders, neoplastic diseases,
edematous states, cerebral edema.
Ophthalmic ointment and solution: for the treatment of steroid responsive inflammatory conditions of the palpebral and bulbar conjunctiva, cornea, and anterior segment of the globe. Ophthalmic solution only: for the treatment of steroid responsive inflammatory conditions of the external auditory meatus Topic cream: for relief of the inflammatory and pruritic manifestations of corticosteroid-responsive dermatoses Oral aerosol: for the treatment of bronchial asthma and related corticosteroid responsive bronchospastic states intractable to adequate trial of conventional therapy Intranasal aerosol: for the treatment of allergic ot inflammatory nasal conditions, and nasal polyps |
| Pharmacodynamics | Dexamethasone and its derivatives, dexamethasone sodium phosphate and dexamethasone acetate, are synthetic glucocorticoids. Used for its antiinflammatory or immunosuppressive properties and ability to penetrate the CNS, dexamethasone is used alone to manage cerebral edema and with tobramycin to treat corticosteroid-responsive inflammatory ocular conditions. |
| Mechanism of action | Dexamethasone is a glucocorticoid agonist. Unbound dexamethasone crosses cell membranes and binds with high affinity to specific cytoplasmic glucocorticoid receptors. This complex binds to DNA elements (glucocorticoid response elements) which results in a modification of transcription and, hence, protein synthesis in order to achieve inhibition of leukocyte infiltration at the site of inflammation, interference in the function of mediators of inflammatory response, suppression of humoral immune responses, and reduction in edema or scar tissue. The antiinflammatory actions of dexamethasone are thought to involve phospholipase A2 inhibitory proteins, lipocortins, which control the biosynthesis of potent mediators of inflammation such as prostaglandins and leukotrienes. |
| Absorption | 80-90% |
| Volume of distribution | Not Available |
| Protein binding | 70% |
| Metabolism | Hepatic. |
| Route of elimination | Not Available |
| Half life | 36-54 hours |
| Clearance | Not Available |
| Toxicity | Oral, rat LD50: >3 gm/kg. Signs of overdose include retinal toxicity, glaucoma, subcapsular cataract, gastrointestinal bleeding, pancreatitis, aseptic bone necrosis, osteoporosis, myopathies, obesity, edemas, hypertension, proteinuria, diabetes, sleep disturbances, psychiatric syndromes, delayed wound healing, atrophy and fragility of the skin, ecchymosis, and pseudotumor cerebri. |