DEXACORT
Clinical safety rating: caution
Comprehensive clinical and safety monograph for DEXACORT (DEXACORT).
Dexamethasone is a glucocorticoid receptor agonist that modulates gene expression to produce anti-inflammatory and immunosuppressive effects by inhibiting phospholipase A2, reducing prostaglandin and leukotriene synthesis, and suppressing cytokine production.
| Metabolism | Hepatic via CYP3A4; also undergoes 11-beta-hydroxysteroid dehydrogenase type 2 (11β-HSD2) mediated metabolism. |
| Excretion | Renal (approximately 80% as inactive metabolites, <5% unchanged), biliary/fecal (minor, approximately 15-20%) |
| Half-life | Plasma terminal elimination half-life is 2.8-3.5 hours in adults, but the biological half-life (duration of HPA axis suppression) is 24-36 hours due to prolonged receptor occupancy |
| Protein binding | Approximately 77% bound, primarily to corticosteroid-binding globulin (CBG) and albumin |
| Volume of Distribution | 0.8-1.0 L/kg (apparent Vd), indicating extensive tissue distribution |
| Bioavailability | Oral: approximately 80%; IM: nearly 100% (slow absorption) |
| Onset of Action | IV bolus: minutes (glucocorticoid effect); Oral: 1-2 hours (peak effects at 4-6 hours); IM: 2-4 hours |
| Duration of Action | Duration of HPA axis suppression: 1.5-2.5 days after single dose; anti-inflammatory effects persist for 24-36 hours |
| Molecular Weight | 392.46 |
Oral: 0.75-9 mg/day in divided doses; IV: 0.5-9 mg/day every 6-12 hours; IM: 4-20 mg every 2 weeks.
| Dosage form | AEROSOL, METERED |
| Renal impairment | No adjustment needed for GFR >10 mL/min; for GFR <10 mL/min, consider 50% dose reduction. |
| Liver impairment | Child-Pugh Class A: no adjustment; Class B: reduce dose by 50%; Class C: avoid use or use with extreme caution. |
| Pediatric use | Oral/IV: 0.02-0.3 mg/kg/day in divided doses every 6-12 hours; maximum 9 mg/day. |
| Geriatric use | Start at lower end of dosing range (e.g., 0.75-3 mg/day) due to increased risk of osteoporosis and hyperglycemia; monitor bone density and glucose levels. |
| 1st trimester | Corticosteroids are associated with an increased risk of cleft lip and palate with first-trimester exposure. Use only if clearly needed, with a risk-benefit assessment. |
| 2nd trimester | Use with caution; may cause fetal adrenal suppression. Monitor for intrauterine growth restriction with prolonged use. |
| 3rd trimester | Use with caution; may cause neonatal adrenal suppression after delivery. Prolonged exposure may increase risk of preterm delivery. |
Clinical note
Comprehensive clinical and safety monograph for DEXACORT (DEXACORT).
| Placental transfer | Readily crosses placenta; dexamethasone is poorly metabolized by the placenta, leading to higher fetal exposure compared to prednisolone. |
| Breastfeeding | Corticosteroids are excreted into breast milk in low amounts. Dexamethasone levels are minimal at maternal doses up to 10 mg/day. Potential for adrenal suppression in the infant is low with short-term use. Monitor infant for signs of adrenal suppression with prolonged high maternal doses. |
■ FDA Black Box Warning
None.
| Serious Effects |
Systemic fungal infectionsAdministration of live or live-attenuated vaccines in patients receiving immunosuppressive dosesKnown hypersensitivity to dexamethasone or any component
| Precautions | Immunosuppression and increased susceptibility to infections, Adrenal suppression with prolonged use, Cushing's syndrome with chronic therapy, Osteoporosis with long-term use, Gastrointestinal perforation or bleeding, Psychiatric disturbances including mood swings, euphoria, or depression, Posterior subcapsular cataracts and glaucoma, Kaposi sarcoma, Negative nitrogen balance, Growth suppression in children, Thrombotic events, Concomitant use with live or live attenuated vaccines contraindicated |
| Food/Dietary | Avoid grapefruit and grapefruit juice as they may increase dexamethasone levels. Avoid excessive salt intake as glucocorticoids can cause fluid retention (though minimal with dexamethasone). Limit alcohol as it can increase risk of gastrointestinal side effects. |
Loading safety data…
| Lactation Rating | L2 (Safer) |
| Teratogenic Risk | First trimester: Increased risk of cleft palate (odds ratio 1.3-3.3) and intrauterine growth restriction. Second/third trimester: Maternal corticosteroid use linked to preterm birth and low birth weight. Long-term exposure may increase risk of adrenal suppression in neonate. |
| Fetal Monitoring | Blood pressure, blood glucose (especially in diabetics), fetal growth via ultrasound (every 4 weeks). Assess for signs of maternal osteoporosis with prolonged use. |
| Fertility Effects | May suppress ovulation (dose-dependent) due to inhibition of gonadotropin release. Reversible upon discontinuation. |
| Clinical Pearls | DEXACORT is a brand name for dexamethasone, a potent long-acting glucocorticoid. It has zero mineralocorticoid activity, making it suitable for conditions requiring high-dose glucocorticoid without salt retention. Crosses blood-brain barrier readily; used in cerebral edema and as antiemetic in chemotherapy. Taper dose to avoid adrenal insufficiency. Monitor for hyperglycemia, especially in diabetic patients. Can cause acute pancreatitis; consider in abdominal pain. |
| Patient Advice | Take exactly as prescribed; do not stop suddenly to avoid withdrawal symptoms such as fatigue, joint pain, and fever. · Report any signs of infection (fever, sore throat) as this drug can mask symptoms. · Avoid live vaccines while taking this medication. · Monitor blood sugar if diabetic; may require adjustment of diabetes medications. · Inform all healthcare providers including dentists that you are taking corticosteroid therapy. |