Dexamethasone dosage

Severe stress, including serious infection, surgery, or trauma, may require an increase in dexamethasone dosage... 

A patient, dependent on dexamethasone due to brain oedema caused by a tumour, deteriorated rapidly, with headache and lethargy, when aminoglutethimide was also given. The problem was solved by withdrawing the aminoglutethimide and temporarily increasing the dexamethasone dosage from 6 to 16 mg daily. ... 

A recent multi-institution survey in Japan drew attention to an important effect of histamine H2 antagonists on docetaxel-induced skin toxicity. Analyses revealed that administration of H2 blockers was associated with a significantly higher incidence of acral erythema (hand-foot syndrome palmar-plantar erythrodysesthesia compare with hand-foot skin reaction. Sects. 13.3.2 and 13.3.3 and see Fig. 13.1) and facial erythema. Steroids and H2 blockers affect the metabolism of docetaxel by cytochrome P45o3A4 (CYP3A4), but dexamethasone dosage did not change the incidence of hand-foot syndrome or facial edema. 

Corticosteroids play a key role in the management of SVCS, particularly in cases of lymphoma, because these tumors inherently respond to corticosteroid therapy. They are also helpful in the setting of respiratory compromise. Corticosteroids benefit patients who are receiving radiation therapy by reducing local radiation-induced inflammation and increased intracranial pressure. Dexamethasone 4 mg intravenously or by mouth every 6 hours is a frequently used regimen. The dosage should be tapered on completion of radiation therapy or resolution of symptoms. 

Concomitant medication with inducers of drug c/earance. Patients on rifampin should receive caspofungin 70 mg/day. Patients on nevirapine, efavirenz, carbamazepine, dexamethasone, or phenytoin may require an increase in dosage to caspofungin 70 mg/day. 

Reversed-phase liquid chromatographic determination of dexamethasone acetate and cortisone acetate in bulk drugs dosage forms. (164)... 

Trichlormethiazide is often given in combination with dexamethasone because in this way effects can be achieved with a minimum dosage of trichlormethiazide, since tire two drugs are complementary in their action. Studies in humans and experimental animals have shown that trichlormethiazide presents a favorable pattern of lower potassium excretion than the other thiazides. The clinically determined saluretic potency of trichlormethiazide was estimated to be 10-20 times lower than that of hydrochlorothiazide and 100-200 times lower than that of chlorothiazide this results in decrease in the incidence of hypokalemic manifestations. 

An apparent association between severe retinopathy of prematurity and dexamethasone therapy has been shown in a retrospective study (SEDA-20, 372 76). Infants treated with dexamethasone required longer periods of mechanical ventilation (44 versus 26 days), had a longer duration of supplemental oxygen (57 versus 29 days), had a higher incidence of patent ductus arteriosus (28/38 versus 18/52), and required surfactant therapy more often for respiratory distress syndrome (17/38 versus 11/52). Prospective, randomized, controlled studies are needed to correct for differences in severity of cardiorespiratory disease. Until such studies are available, careful consideration must be given to indications, dosage, time of initiation, and duration of treatment with dexamethasone in infants of extremely low birthweight. 

Diabetes mellitus in a 36-year-old man with acute pancreatitis could not be controlled with continuous subcutaneous insulin infusion, even with doses up to 1800 U/ day, because of insulin resistance (168). Intravenous insulin by pump had to be stopped because of a catheter infection. The continuous subcutaneous infusion of freeze-dried insulin and the addition of aprotinin, a protease inhibitor, soluble dexamethasone or prednisolone, and intravenous immunoglobulin was ineffective. An implantable pump for intraperitoneal delivery established good regulation at a dosage of 30 U/day. 

Cevc, G., and G. Blume. 2004. Hydrocortisone and dexamethasone in very deformable drug carriers have increased biological potency, prolonged effect, and reduced therapeutic dosage. Biochim Biophys Acta 1663 61. 

Injectables are the next most common dosage form. A common preparation is to dilute an aliquot with mobile phase as is the case for the USP procedures for dexamethasone [3, p. 475]. Another common approach is to dilute with methanol, as is done for the assay of diazepam [3, p. 491]. 

L. L. Ng, Reverse phase liquid chromatographic determination of dexamethasone acetate in cortisone acetate in bulk drug substances and dosage forms Method development, J. Assoc. Off. Anal. Chem., 70 829(1987). 

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