Dexamethasone

# Dexamethasone ## Overview - **Classification**: Synthetic long-acting Corticosteroid (glucocorticoid). - **Mechanism**: Potently suppresses inflammation and immune responses by inhibiting multiple inflammatory mediators and decreasing capillary permeability. Minimal mineralocorticoid activity. ## Primary Indications 1. **Inflammation/Allergic Reactions** - Severe allergic reactions, asthma exacerbations, dermatologic conditions. 2. **Cerebral Edema** - Especially associated with brain tumors. 3. **Chemotherapy-Induced Nausea and Vomiting (CINV)** - Prophylaxis and treatment. 4. **Adrenal Insufficiency** - Replacement therapy (often with a mineralocorticoid). ## Adult Dosing ### Standard Dosing **Inflammation/Immunosuppression** (Highly variable by condition) - **Dose**: **0.75 mg** to **9 mg** - **Frequency**: **Daily** (single or divided doses) - **Route**: PO, IV, IM - **Duration**: Highly variable, short-term for acute, long-term for chronic **Cerebral Edema** (associated with brain tumors) - **Dose**: Initial **10 mg** - **Frequency**: Followed by **4 mg** every **6 hours** - **Route**: IV/IM - **Duration**: For 2-4 days, then tapered **CINV Prophylaxis** (Highly emetogenic chemotherapy) - **Dose**: **12 mg** - **Frequency**: Once, **30-60 minutes before chemotherapy** - **Route**: PO, IV ### Dose Adjustments - **Renal Impairment**: No specific dose adjustment generally required. Metabolized hepatically. - **Hepatic Impairment**: Use caution; monitor for increased adverse effects. No specific dose adjustments. - **Elderly Patients**: Use caution, may be more susceptible to adverse effects. Consider lower initial doses. ## Pediatric Dosing (Consult specialist for complex cases) ### Neonates (0-28 days) - **Indication**: Bronchopulmonary Dysplasia (BPD) prevention/treatment (controversial, typically short course) - **Dose**: **0.1-0.25 mg/kg** - **Frequency**: Every **12-24 hours** - **Maximum**: **0.25 mg/kg/day** - **Special Notes**: Associated with potential neurodevelopmental impairment. Use with extreme caution. ### Infants (1-12 months) - **Indication**: Croup (moderate to severe) - **Dose**: **0.6 mg/kg** (single dose) - **Frequency**: Single dose - **Maximum**: **10 mg** - **Special Notes**: Oral liquid preferred; can be mixed with juice or formula (but not for long-term storage). ### Children (1-12 years) - **Indication**: Croup (moderate to severe) - **Dose**: **0.6 mg/kg** (single dose) - **Frequency**: Single dose - **Maximum**: **10 mg** - **Indication**: Cerebral Edema (brain tumor related) - **Dose**: Initial **0.5-1.5 mg/kg/day** - **Frequency**: Divided every **4-6 hours** - **Maximum**: **16 mg/day** initially, then tapered ### Adolescents (13-18 years) - **Dose**: Generally follow **adult dosing guidelines**. - **Maximum**: Adult maximum doses apply. ## Safety Information ### Contraindications - **Absolute**: Systemic fungal infections - **Absolute**: Hypersensitivity to dexamethasone or components - **Relative**: Administration of live or live-attenuated vaccines during immunosuppressive doses - **Relative**: Untreated serious infections ### Common Adverse Effects - **Very Common (>10%)**: Insomnia, increased appetite, indigestion, fluid retention. - **Common (1-10%)**: Mood changes, hyperglycemia, hypertension, muscle weakness, skin thinning. - **Serious but Rare**: Adrenal suppression, osteoporosis, avascular necrosis, GI perforation, cataracts, glaucoma. ### Key Drug Interactions - **CYP3A4 Inducers (e.g., Phenytoin, Rifampin)**: Decreased dexamethasone levels. May require increased dexamethasone dose. - **CYP3A4 Inhibitors (e.g., Azole Antifungals, Macrolides)**: Increased dexamethasone levels. May require decreased dexamethasone dose. - **NSAIDs**: Increased risk of GI ulceration and bleeding. Monitor for GI symptoms. - **Warfarin**: Variable effect on INR; monitor INR closely. - **Diuretics (Thiazide/Loop)**: Increased risk of hypokalemia. Monitor potassium levels. ## Monitoring & Follow-up - **Before Treatment**: Baseline blood pressure, glucose, electrolytes (especially K+), bone density (for long-term). - **During Treatment**: Blood pressure, glucose, electrolytes regularly (frequency based on duration/dose). - **Clinical Signs**: Monitor for infection, mood changes, GI upset, fluid retention, muscle weakness. ## Clinical Pearls - 💡 **Tip 1**: Administer oral doses with food to minimize GI upset. - 💡 **Tip 2**: For short-term use (<7-10 days), tapering is often not necessary, but always assess for adrenal suppression if higher doses or longer duration. - 💡 **Tip 3**: Long-term use requires calcium/vitamin D supplementation and bone density monitoring. - 💡 **Tip 4**: Avoid abrupt discontinuation after prolonged therapy to prevent adrenal crisis. Taper slowly over weeks to months. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.