DEXONE 0.5
Clinical safety rating: caution
Comprehensive clinical and safety monograph for DEXONE 0.5 (DEXONE 0.5).
Dexamethasone is a glucocorticoid receptor agonist, binding to the glucocorticoid receptor (GR) and modulating gene expression through transactivation and transrepression. It inhibits phospholipase A2, reduces prostaglandin and leukotriene synthesis, suppresses cytokine production (IL-1, IL-2, IL-6, TNF-alpha), and decreases immune cell migration and activation.
| Metabolism | Primarily hepatic metabolism via CYP3A4; also metabolized by 11β-hydroxysteroid dehydrogenase (11β-HSD) to inactive metabolites. Elimination half-life is approximately 3-4 hours, but biologic half-life is longer (36-54 hours due to intracellular activity). |
| Excretion | Renal: 70-80% (mostly as 6β-hydroxydexamethasone); biliary/fecal: 10-15% |
| Half-life | 3.0-4.5 hours; prolonged in hepatic impairment (up to 6-8 hours) or concurrent CYP3A4 inhibitors |
| Protein binding | 77-84% (corticosteroid-binding globulin, albumin) |
| Volume of Distribution | 0.8-1.2 L/kg; indicates extensive tissue penetration, including CNS (0.3-0.6 L/kg in CSF) |
| Bioavailability | Oral: 60-80%; IM: 80-100% (formulation-dependent) |
| Onset of Action | Oral: 1-2 hours; IV: immediate (minutes); IM: 2-3 hours |
| Duration of Action | Oral/IV: 36-54 hours (single dose); IM: 24-36 hours; duration prolonged with high doses or continuous therapy |
| Molecular Weight | 392.46 |
0.5 mg orally once daily, with gradual taper to lowest effective dose
| Dosage form | TABLET |
| Renal impairment | No adjustment required for GFR >30 mL/min; avoid in GFR <30 mL/min due to increased risk of adverse effects |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: avoid use |
| Pediatric use | 0.02-0.3 mg/kg/day orally divided once daily or twice daily; maximum 0.5 mg/day |
| Geriatric use | Initiate at lowest dose (0.25 mg daily) and titrate cautiously due to increased risk of osteoporosis, hyperglycemia, and immunosuppression |
| 1st trimester | Associated with increased risk of cleft palate and intrauterine growth restriction; use only if clearly needed. |
| 2nd trimester | May cause fetal adrenal suppression; monitor fetal growth and amniotic fluid volume. |
| 3rd trimester | Risk of premature closure of ductus arteriosus, neonatal adrenal suppression, and hypoglycemia; avoid prolonged use. |
Clinical note
Comprehensive clinical and safety monograph for DEXONE 0.5 (DEXONE 0.5).
| Placental transfer | Crosses placenta extensively; metabolized by placental 11β-HSD2 to a lesser extent, resulting in significant fetal exposure. |
| Breastfeeding | Dexamethasone is excreted into breast milk in small amounts. Short-term use is likely compatible, but monitor infant for adrenal suppression with prolonged or high maternal doses. |
■ FDA Black Box Warning
No FDA black box warning specific to dexamethasone.
| Serious Effects |
Systemic fungal infectionAdministration of live or live attenuated vaccines
| Precautions | Increased risk of infections due to immunosuppression, Adrenal suppression and withdrawal syndrome with abrupt discontinuation, Osteoporosis with long-term use, Hyperglycemia and diabetes exacerbation, Gastrointestinal perforation or bleeding, Cushing's syndrome with chronic use, Ocular effects: glaucoma, cataracts, central serous chorioretinopathy, Psychiatric disturbances (e.g., euphoria, psychosis), Growth suppression in children, Fluid and electrolyte disturbances (sodium retention, potassium loss) |
| Food/Dietary | Avoid grapefruit and grapefruit juice as they may increase dexamethasone levels. Limit high-sodium foods to reduce fluid retention. Increase potassium-rich foods (e.g., bananas, oranges) to counteract hypokalemia. No clinically significant interaction with alcohol, but excessive use may increase gastrointestinal side effects. |
Loading safety data…
| Lactation Rating |
| L2 (Safer) |
| Teratogenic Risk | First trimester: Increased risk of orofacial clefts (odds ratio ~3.4). Second/third trimester: Fetal adrenal suppression, intrauterine growth restriction, oligohydramnios. Prolonged use: Premature birth, low birth weight. |
| Fetal Monitoring | Maternal: Blood pressure, blood glucose, weight gain, signs of adrenal insufficiency. Fetal: Serial ultrasound for growth, amniotic fluid index, fetal heart rate monitoring. Newborn: Observe for adrenal suppression, hypoglycemia. |
| Fertility Effects | May suppress ovulation due to interference with gonadotropin release. Long-term use can disrupt menstrual cycles and reduce fertility, which is reversible upon discontinuation. |
| Clinical Pearls | DEXONE 0.5 (dexamethasone 0.5 mg) is a potent glucocorticoid. For asthma exacerbations, early administration reduces hospitalization. Use with caution in patients with diabetes; monitor blood glucose closely. Avoid abrupt withdrawal after prolonged use; taper to prevent adrenal insufficiency. Consider Pneumocystis jirovecii prophylaxis in long-term therapy with other immunosuppressants. Not suitable for routine maintenance therapy in chronic conditions due to high potency and long half-life. |
| Patient Advice | Take exactly as prescribed, with food or milk to reduce stomach upset. · Do not stop suddenly; dose must be tapered under doctor's guidance. · Report any signs of infection (fever, sore throat) as this drug can mask symptoms. · Avoid live vaccines while on this medication. · Notify all healthcare providers that you are taking dexamethasone. · Carry a steroid warning card or medical alert bracelet. |