Dexamethasone parenteral

Betamethasone is hardly ever used orally. It has a long duration of activity and can therefore also be used for alternate-day therapy. The parenteral formulation is also the sodium phosphate salt which when given IV or IM has a rapid onset of action. There are many similarities with dexamethasone such as their metabolic pathways and the indications for which both steroids are used, like the prevention of neonatal RDS and reduction of raised intracranial pressure. Combinations of betamethasone acetate and sodium phosphate have, when used for intra-articular and intra-lesional injections, the dual advantage of a rapid onset of action together with the long duration of action of a depot preparation. 

For parenteral administration in intensive therapy or in emergendes, the sodium phosphate ester may be given intravenously by injection or infusion, or intramuscularly by injection. Dexamethasone sodium phosphate is also used in the treatment of cerebral edema caused by malignancy. The sodium phosphate ester is given by intra-articular, intra-lesional or soft tissue injection. Dexamethasone acetate may be given by intramuscular injection in conditions where corticosteroid treatment is indicated, but a prompt response of short duration is not required. 

Glucocorticoids are the first-line treatment for mild to moderate croup. They are effective via many routes (inhaled, oral, parenteral), but dexamethasone given orally as one single dose or in two divided doses has been shown to be as effective as the same dose given via the parenteral route and superior in efficacy to nebulised budesonide. 

American Journal of Veterinary Research 59 1039-1043 Rush B R, Worster A A, Flaminio M J et al 1998c Alteration in adrenocortical function in horses with recurrent airway obstruction after aerosol and parenteral administration of beclomethasone dipropionate and dexamethasone, respectively. American Journal of Veterinary Research 59 1044-1047... 

Corticosteroids may be an effective rescue therapy for status migrain-osus (a severe, continuous migraine that may last up to 1 week). Open-label studies also suggest that short courses of orally or parenterally administered prednisone, dexamethasone, and hydrocortisone appear to be useful in the management of refractory headache that has persisted for several days. " ... 

In aqueous solution, prednisolone sodium phosphate and dexamethasone sodium phosphate are more stable than hydrocortisone sodium succinate. At a pH of about 8, the acid groups are sufficiently ionised to make the substance very soluble, while the phosphate ester is reasonably stable at this pH. Water soluble corticosteroids are mainly used in parenteral preparations, eye drops, oral mixtures and enemas. Examples are prednisolone oral mixtures and dexamethasone injections. 

Corticosteroid sodium phosphate salts used in parenteral preparations, i.e., eye, and ear drops, have been separated by reversed phase ion pair chromatography on silanized silica gel stationary phase, using aqueous triethylamine-methanol (3 2, v/v, pH s 4.2) as mobile 4tase. The separated spots were assayed by densitometry at a wavelength of 240 nm (73). Sodium phosphate salts of betamethasone, dexamethasone, and prednisolone have been quantitatively determined in the presence of chloramphenicol in eye and ear drops, also methyl and propyl parabens, and phenols. 

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