Dexamethasone for inflammatory, allergic, and endocrine disorders

Dexamethasone is a synthetic corticosteroid used in various dosage forms including tablets, injections, and concentrated solutions. It helps reduce inflammation and suppress the immune system, making it useful in treating a wide range of inflammatory, allergic, autoimmune, hematologic, endocrine, and neoplastic conditions. Dexamethasone is available as oral tablets, injectable solution (including preservative-free forms), and oral solutions for different treatment needs.

Dexamethasone is approved for treating numerous conditions across different organ systems:

• Endocrine disorders: primary or secondary adrenocortical insufficiency (often with mineralocorticoid support), congenital adrenal hyperplasia, nonsuppurative thyroiditis, hypercalcemia associated with cancer, shock unresponsive to conventional therapy due to adrenal insufficiency.
• Inflammatory and rheumatic diseases: rheumatoid arthritis, juvenile rheumatoid arthritis, osteoarthritis, bursitis, epicondylitis, acute gouty arthritis, ankylosing spondylitis, psoriatic arthritis.
• Collagen and dermatologic diseases: systemic lupus erythematosus, pemphigus, severe erythema multiforme (Stevens-Johnson syndrome), exfoliative dermatitis, bullous dermatitis herpetiformis, seborrheic dermatitis, mycosis fungoides.
• Allergic states: severe or incapacitating bronchial asthma, atopic/contact dermatitis, drug hypersensitivity reactions, serum sickness, allergic rhinitis, urticarial transfusion reactions, acute noninfectious laryngeal edema.
• Ophthalmic diseases: severe acute and chronic inflammatory eye conditions, such as iritis, iridocyclitis, chorioretinitis, uveitis, optic neuritis, herpes zoster ophthalmicus.
• Gastrointestinal diseases: regional enteritis, ulcerative colitis.
• Respiratory diseases: symptomatic sarcoidosis, berylliosis, fulminating or disseminated pulmonary tuberculosis (with appropriate chemotherapy), Loeffler's syndrome, aspiration pneumonitis.
• Hematologic disorders: autoimmune hemolytic anemia, idiopathic thrombocytopenic purpura (IV only), erythroblastopenia, congenital hypoplastic anemia.
• Neoplastic diseases: palliative management of leukemias and lymphomas.
• Edematous states: nephrotic syndrome without uremia.
• Nervous system: acute exacerbations of multiple sclerosis, cerebral edema associated with brain tumors, head injury, or craniotomy.
• Miscellaneous: tuberculous meningitis with subarachnoid block, trichinosis with neurologic/myocardial involvement, diagnostic testing of adrenocortical hyperfunction.
• Injections for intra-articular, soft tissue, or intralesional use: synovitis, bursitis, tenosynovitis, keloids, localized inflammatory dermatoses, ganglia.

Dexamethasone; Dexamethasone sodium phosphate

Dexamethasone is a synthetic glucocorticoid that mimics naturally occurring hormones produced by the adrenal cortex. It works by suppressing inflammation and modifying the body's immune response. Unlike some corticosteroids, dexamethasone has minimal sodium-retaining effects at anti-inflammatory doses. It inhibits the release of substances that cause inflammation, reducing swelling, redness, and allergic symptoms. It also suppresses immune activity, which helps manage autoimmune disorders but increases infection risk.

Oral Tablets and Oral Solutions: Dosage varies widely depending on the condition being treated, ranging from 0.5 mg to 9 mg daily or higher for severe conditions. Dosage is individualized, with gradual tapering recommended after long-term use to avoid adrenal insufficiency.

Intramuscular or Intravenous Injection: Initial doses generally range from 0.5 mg/day to 9 mg/day depending on severity. For certain acute or life-threatening conditions, much higher doses (e.g., 1-6 mg/kg for shock) may be used. In cerebral edema, an initial intravenous dose of 10 mg followed by 4 mg every 6 hours intramuscularly is typical until improvement. Maintenance dosing is based on clinical response and should be tapered.

Intra-articular, Soft Tissue, or Intralesional Administration: Typical doses for large joints are 2-4 mg, small joints 0.8-1 mg, soft tissues 2-4 mg, tendon sheaths 0.4-1 mg. Frequency ranges from once every 3-5 days to once every 2-3 weeks.

Dosage should be adjusted carefully according to disease severity, response, and patient factors. Increased doses of rapidly acting corticosteroids may be needed during stress.

Dexamethasone is contraindicated in patients with systemic fungal infections and those hypersensitive to any ingredients in the formulation.

Contraindications: Systemic fungal infections; hypersensitivity to any components.

Serious Risks: Epidural administration is not approved and may cause paralysis or death. Corticosteroids suppress immune function and increase infection risk, including risk of reactivation of latent tuberculosis, hepatitis B virus, varicella, measles, and Strongyloides infestation. Monitor for infections and consider dose reduction or discontinuation if infection develops.

Prolonged use may cause osteoporosis, adrenal insufficiency, cataracts, glaucoma, hypertension, fluid retention, and electrolyte imbalances. Use caution in patients with heart failure, hypertension, renal impairment, myasthenia gravis, and psychiatric disorders.

Vaccines: Live vaccines are contraindicated during immunosuppressive dose therapy. Killed vaccines may be less effective.

Allergic reactions such as anaphylaxis and sulfite sensitivity (for sodium sulfite-containing preparations) have been reported.

Pregnancy: Use only if benefits outweigh risks; newborns of treated mothers should be monitored for hypoadrenalism.

Common and serious adverse effects include:

• Allergic reactions: anaphylaxis, angioedema
• Cardiovascular: hypertension, arrhythmias, heart failure, edema, myocardial rupture post-infarction
• Dermatologic: acne, rash, fragile skin, impaired wound healing, petechiae, sweating
• Endocrine/metabolic: hyperglycemia, Cushingoid state, menstrual irregularities, suppression of growth in children, latent diabetes manifestation
• Fluid/electrolyte imbalance: sodium and fluid retention, potassium loss, hypokalemic alkalosis
• Gastrointestinal: peptic ulcers with risk of perforation, pancreatitis, ulcerative esophagitis
• Musculoskeletal: osteoporosis, steroid myopathy, aseptic necrosis, tendon rupture
• Neurological/psychiatric: mood changes, depression, convulsions, increased intracranial pressure, insomnia
• Ophthalmic: cataracts, glaucoma, increased intraocular pressure
• Others: weight gain, moon face, hiccups

Dexamethasone is metabolized by CYP3A4, leading to multiple drug interactions:

• CYP3A4 inducers (e.g., barbiturates, phenytoin, carbamazepine, rifampin) may decrease dexamethasone levels requiring dose increase.
• CYP3A4 inhibitors (e.g., erythromycin, ketoconazole, itraconazole, clarithromycin, ritonavir) may increase dexamethasone levels, raising risk of corticosteroid side effects; monitor patients accordingly.
• Dexamethasone is a moderate inducer of CYP3A4 and may decrease plasma levels of coadministered CYP3A4 substrates (e.g., indinavir, erythromycin).
• Concurrent use with warfarin may inhibit anticoagulant effect; monitor coagulation frequently.
• Potassium-depleting agents (e.g., amphotericin B, diuretics) increase risk of hypokalemia.
• Anticholinesterase agents may cause severe weakness in myasthenia gravis; consider withdrawal 24 hours before dexamethasone.
• Antidiabetics: corticosteroids may increase blood glucose; adjust doses accordingly.
• Other: interactions reported with macrolide antibiotics, cholestyramine, cyclosporine, digitalis glycosides, ephedrine, estrogens, phenytoin, thalidomide, NSAIDs, and vaccines.

Safety in pregnancy has not been established; use only when benefits outweigh risks. Infants born to mothers treated with corticosteroids should be observed for signs of hypoadrenalism. Effects on fertility or nursing are not detailed; caution is advised.

Specific overdose manifestations and management guidance are not detailed in the supplied labels.

No specific storage conditions provided in reference to supplied labels.