DECADRON
Clinical safety rating: caution
Comprehensive clinical and safety monograph for DECADRON (DECADRON).
Dexamethasone is a glucocorticoid receptor agonist, binding to the glucocorticoid receptor and modulating gene expression to produce anti-inflammatory and immunosuppressive effects. It also suppresses adrenal function by inhibiting ACTH secretion.
| Metabolism | Primarily hepatic via cytochrome P450 3A4 (CYP3A4) to inactive metabolites. Minimal renal excretion of unchanged drug. |
| Excretion | Renal (65-80% as 17-hydroxycorticosteroids and 20-hydroxycorticosteroids after hepatic metabolism); biliary/fecal (minor, <10%) |
| Half-life | Terminal half-life: 3-4 hours (plasma); biological half-life: 36-54 hours (due to intracellular receptor binding); clinical context: duration of HPA axis suppression longer than plasma half-life |
| Protein binding | 70-80% bound; primarily to corticosteroid-binding globulin (CBG) and albumin |
| Volume of Distribution | 0.5-1.0 L/kg; clinical meaning: distributes widely into tissues, including CNS (crosses blood-brain barrier) |
| Bioavailability | Oral: 60-70%; IM: 100%; IV: 100% |
| Onset of Action | Oral: 1-2 hours; IV: rapid (minutes); IM: 1-2 hours; topical: variable (hours to days) |
| Duration of Action | Single dose: 1-3 days (biological effects); clinical notes: duration depends on dose, route, and underlying condition; HPA axis suppression may persist for weeks after chronic therapy |
| Molecular Weight | 392.46 |
| Action Class | Glucocorticoids |
| Brand Substitutes | DEXAMETHASONE Tablet, Methasone Tablet, Decakem Tablet, Dexomet Tablet |
0.75-9 mg/day orally in divided doses every 6-12 hours; or 0.5-9 mg/day IM/IV in divided doses every 12 hours for acute conditions; for cerebral edema, IV loading dose of 10 mg followed by 4 mg IM/IV every 6 hours.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for GFR <15-90 mL/min; no specific guideline for dialysis; use with caution in severe renal impairment. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce by 50%; Child-Pugh C: reduce by 75% or consider alternative. |
| Pediatric use | 0.02-0.3 mg/kg/day or 0.6-9 mg/m²/day orally in divided doses every 6-12 hours; for cerebral edema, IV 0.1-0.5 mg/kg/day divided every 6 hours. |
| Geriatric use | Start at lowest effective dose due to increased risk of osteoporosis and hyperglycemia; monitor for fluid retention and delirium; dose based on severity of condition and renal/hepatic function. |
| 1st trimester | Corticosteroids are associated with increased risk of orofacial clefts when used in first trimester. Use only if clearly needed. |
| 2nd trimester | May be used for fetal lung maturation in preterm labor; otherwise, weigh risks and benefits. |
| 3rd trimester | Chronic use may lead to neonatal adrenal suppression. Use only if benefits outweigh risks. |
Clinical note
Comprehensive clinical and safety monograph for DECADRON (DECADRON).
| Placental transfer | Dexamethasone crosses the placenta with approximately 40-60% of maternal concentration reaching the fetus. It is poorly metabolized by the placenta, leading to significant fetal exposure. |
| Breastfeeding | Dexamethasone is excreted into breast milk in low amounts. At therapeutic doses, the American Academy of Pediatrics considers it compatible with breastfeeding. Monitor infant for growth and adrenal suppression with prolonged high-dose maternal therapy. |
■ FDA Black Box Warning
None.
| Serious Effects |
Systemic fungal infectionsHypersensitivity to dexamethasone or any component of the formulationAdministration of live or live-attenuated vaccines (due to immunosuppression)
| Precautions | Increased risk of infections due to immunosuppression, Adrenal suppression with prolonged use; taper dose to avoid withdrawal, Osteoporosis with long-term use, Gastrointestinal perforation or bleeding, Hyperglycemia and diabetes mellitus exacerbation, Psychiatric disturbances (e.g., euphoria, psychosis), Kaposi sarcoma (rare), Ocular effects (cataracts, glaucoma) |
| Food/Dietary | Avoid grapefruit and grapefruit juice as they may increase dexamethasone levels. Limit sodium intake to reduce fluid retention. Maintain adequate potassium intake (e.g., bananas, oranges) as dexamethasone can cause hypokalemia. Avoid excessive alcohol consumption. |
Loading safety data…
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | First trimester: Increased risk of cleft palate (OR 3.4) with systemic use; avoid unless life-threatening. Second/third trimesters: Risk of fetal adrenal suppression, intrauterine growth restriction (IUGR), and preterm delivery; use lowest effective dose. Category C (no adequate studies); favors risk of orofacial clefts and oligohydramnios. |
| Fetal Monitoring | Monitor maternal blood glucose (steroid-induced hyperglycemia), blood pressure (hypertension), and signs of infection. Fetal: serial ultrasound for growth restriction (IUGR) and amniotic fluid volume; fetal heart rate monitoring if preterm labor risk. Neonatal: assess for adrenal insufficiency if prolonged maternal use. |
| Fertility Effects | May suppress endogenous gonadotropins and hypothalamic-pituitary-adrenal axis, potentially delaying ovulation or spermatogenesis. High doses can cause menstrual irregularities; impact reversible upon discontinuation. |
| Clinical Pearls | Decadron (dexamethasone) is a potent, long-acting glucocorticoid with minimal mineralocorticoid activity. It is commonly used for cerebral edema in brain tumors (e.g., 10 mg IV/PO loading then 4 mg q6h) and for antenatal fetal lung maturation (6 mg IM q12h x4 doses). Due to its long half-life (36-54 hours), it suppresses the hypothalamic-pituitary-adrenal (HPA) axis for up to 48 hours after a single dose. Abrupt discontinuation after >2 weeks of therapy requires taper to avoid adrenal crisis. It is also used as an antiemetic in highly emetogenic chemotherapy (e.g., 20 mg IV prior to chemo). In COVID-19, dexamethasone 6 mg daily for up to 10 days reduces mortality in patients requiring supplemental oxygen. Monitor for hyperglycemia, especially in diabetic patients. |
| Patient Advice | Take exactly as prescribed; do not stop suddenly without consulting your doctor, as this can cause withdrawal symptoms. · Take with food or milk to reduce stomach upset. · Report any signs of infection (fever, sore throat) or unusual bleeding/bruising immediately. · Avoid live vaccines while on this medication. · May cause increased blood sugar; monitor glucose if diabetic and report high readings. · Do not take NSAIDs (e.g., ibuprofen) without doctor approval due to increased risk of gastrointestinal bleeding. · Carry a medical alert card indicating you are taking a corticosteroid. |