Dexamethasone is a potent, long-acting synthetic glucocorticoid with anti-inflammatory, immunosuppressive, anti-allergic, and anti-proliferative properties. It is approximately 25-30 times more potent than hydrocortisone. In the Indian context, it is a critical, low-cost medication widely used across hospital and outpatient settings for a vast array of inflammatory, autoimmune, allergic, and neoplastic conditions. Its role expanded significantly during the COVID-19 pandemic for managing cytokine storm.
Adult: Highly variable based on indication. Anti-inflammatory/Immunosuppressive: 0.5 to 9 mg/day orally in divided doses. Cerebral Edema: Initial IV dose of 10 mg, then 4 mg IM/IV every 6 hours. Anti-emetic (chemotherapy): 8-20 mg IV before chemo, then 8 mg orally twice daily for 2-4 days. Severe COVID-19: 6 mg IV/orally once daily for up to 10 days.
Note: Oral: Take with food or milk to minimize GI upset. Do not stop abruptly; taper gradually after prolonged use (>2 weeks). IV/IM: Can be administered undiluted by IV push over 1-4 minutes or as an infusion in compatible solutions (e.g., NS, D5W).
Dexamethasone binds to intracellular glucocorticoid receptors, forming a complex that translocates to the cell nucleus. This complex binds to Glucocorticoid Response Elements (GREs) on DNA, modulating gene transcription. It increases transcription of anti-inflammatory proteins (e.g., lipocortin-1) and decreases transcription of pro-inflammatory proteins (e.g., cytokines IL-1, IL-2, IL-6, TNF-α, COX-2). It also induces apoptosis of lymphocytes.
Pregnancy: FDA Category C. May cause fetal harm. Crosses placenta. Use only if potential benefit justifies risk. Chronic use associated with low birth weight, adrenal suppression in neonate. Not recommended for treatment of morning sickness.
Driving: May cause dizziness, vertigo, or visual disturbances. Patients should not drive or operate machinery if they experience these effects.
| Warfarin | Dexamethasone may alter INR response (increase or decrease); monitor INR closely. | Major |
| Phenytoin, Phenobarbital, Rifampicin | Induce CYP3A4, increasing dexamethasone metabolism, reducing its efficacy. | Major |
| Ketoconazole, Itraconazole, Clarithromycin | Inhibit CYP3A4, decreasing dexamethasone metabolism, increasing risk of toxicity. | Major |
| NSAIDs (e.g., Ibuprofen, Diclofenac) | Increased risk of GI ulceration and bleeding. | Moderate |
| Diuretics (e.g., Furosemide, Hydrochlorothiazide) | Enhanced potassium loss, leading to severe hypokalemia. | Moderate |
| Insulin, Oral Hypoglycemics | Dexamethasone causes hyperglycemia; may require dose adjustment of anti-diabetic drugs. | Moderate |
| Live Vaccines (e.g., MMR, Varicella, OPV) | Risk of disseminated infection; avoid vaccination during therapy. | Major |
Same composition (Dexamethasone (NA)), different brands: