Dexamethasone
CLINICAL USE
Corticosteroid:Cerebral oedema Suppression of inflammatory and allergic disordersRheumatic disease Congenital adrenal hyperplasia Anti-emetic (unlicensed indication)
DOSE IN NORMAL RENAL FUNCTION
Cerebral oedema: 10 mg IV followed by 4 mg IM every 6 hoursRheumatic disease: intra-articular, intrasynovial: 0.4–4 mg —(as dexamethasone phosphate)soft tissue infiltration: 2–6 mg —Oral: 0.5–10 mg daily, IV/IM: 0.5–24 mg
PHARMACOKINETICS
DOSE IN RENAL IMPAIRMENT
GFR (mL/MIN)
DOSE IN PATIENTS UNDERGOING RENAL REPLACEMENT THERAPIES
IMPORTANT DRUG INTERACTIONS
Potentially hazardous interactions with other drugsAntibacterials: metabolism accelerated by rifampicin; metabolism possibly inhibited by erythromycinAnticoagulants: efficacy of coumarins may be alteredAnti-epileptics: metabolism accelerated by carbamazepine, barbiturates, phenytoin and primidoneAntifungals: increased risk of hypokalaemia with amphotericin – avoid concomitant use; metabolism possibly inhibited by itraconazole and ketoconazole; caspofungin concentration possibly reduced (may need to increase dose). Antivirals: concentration of indinavir, lopinavir and saquinavir possibly reduced; concentration possibly increased by ritonavirCiclosporin: rare reports of convulsions in patients on ciclosporin and high-dose corticosteroidsCytotoxics: increased risk of haematological toxicity with methotrexateDiuretics: enhanced hypokalaemic effects of acetazolamide, loop diuretics and thiazide diureticsVaccines: high dose corticosteroids can impair immune response to vaccines; avoid concomitant use with live vaccines
ADMINISTRATION
Reconstition
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Route
Oral, IV, IM, intra-articular, intrasynovial
Rate of Administration
IV slowly over not less than 5 minutes. If underlying cardiac pathology, infusion over 20–30 minutes advised
Comments
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OTHER INFORMATION
Dexamethasone sodium phosphate 1.3 mg = dexamethasone 1 mg750 mcg of dexamethasone is equivalent to 5 mg prednisolone Injection solution can be administered orally or via naso-gastric tubeTablets will disperse in water