DURANEST
Clinical safety rating: caution
Comprehensive clinical and safety monograph for DURANEST (DURANEST).
Etonidate is an ultrashort-acting nonbarbiturate hypnotic agent that produces anesthesia by enhancing GABA-mediated chloride conductance at GABA-A receptors, leading to central nervous system depression.
| Metabolism | Primarily hepatic via hydrolysis by esterases (plasma and hepatic) to inactive metabolites. Less than 5% excreted unchanged in urine. |
| Excretion | Primarily hepatic metabolism; renal excretion of metabolites accounts for <10% unchanged drug. Biliary/fecal elimination is minimal. |
| Half-life | Terminal elimination half-life is 4.5 hours (range 3-6 hours). Clinical context: Prolonged in severe hepatic impairment but not significantly in renal impairment. |
| Protein binding | 85-90% bound primarily to alpha-1-acid glycoprotein; minor binding to albumin. |
| Volume of Distribution | Vd is 2.5-3.5 L/kg, indicating extensive extravascular distribution and tissue binding. |
| Bioavailability | Oral: 60-70% (first-pass metabolism); Intramuscular: ~90%; Intravenous: 100%. |
| Onset of Action | Intravenous: within 1-2 minutes; Intramuscular: 5-10 minutes; Oral: 30-60 minutes. |
| Duration of Action | Intravenous: 30-60 minutes; Intramuscular: 1-2 hours; Oral: 4-6 hours. Clinical note: Duration may be extended in hepatic disease. |
2-10 mL of a 1-2% solution, subarachnoid injection, single dose only.
| Dosage form | INJECTABLE |
| Renal impairment | No specific guidelines; contraindicated in severe renal impairment due to potential for accumulation of preservatives. |
| Liver impairment | Use with caution; no specific Child-Pugh adjustments available. Contraindicated in severe hepatic disease due to impaired metabolism. |
| Pediatric use | Not recommended for pediatric use due to limited data and high risk of neurotoxicity. |
| Geriatric use | Reduce dose and volume; monitor for prolonged motor block and hypotension. Use lowest effective dose. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for DURANEST (DURANEST).
| Breastfeeding | Excreted in breast milk in low concentrations; M/P ratio not established. Expected milk levels are minimal after regional anesthesia. Use with caution; monitor infant for signs of local anesthetic toxicity (irritability, drowsiness). Instruct mother to discard milk for 4 hours after injection if concerned. |
| Teratogenic Risk | Duranest (etidocaine) is a local anesthetic of the amide type. Limited human data; animal studies show no teratogenicity at clinically relevant doses. Use in first trimester only if clearly needed. Second and third trimesters: no known teratogenic risk; may cause fetal bradycardia if high systemic levels occur. Avoid in near-term unless necessary due to neonatal effects. |
■ FDA Black Box Warning
None.
| Serious Effects |
["Hypersensitivity to etonidate or any component of the formulation","Use as sole anesthetic agent for major surgery without adequate muscle relaxation or intubation","Acute porphyria (relative contraindication)"]
| Precautions | ["Adrenocortical suppression: Etonidate inhibits 11β-hydroxylase, reducing cortisol and aldosterone synthesis; may last up to 24 hours after single dose.","Myoclonus: Involuntary muscle movements occur in up to 70% of patients, especially with rapid injection.","Hypotension: Less pronounced than with other induction agents, but may occur, particularly in hypovolemic patients.","Injection site pain: Common with peripheral administration.","Use in intensive care: Prolonged infusion associated with increased mortality; not recommended for sedation in ICU.","Pregnancy category C: Use only if clearly needed."] |
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| Fetal Monitoring | Continuous maternal ECG, blood pressure, and oxygen saturation during administration. Fetal heart rate monitoring for bradycardia or signs of distress after epidural or high-dose use. Assess for signs of systemic toxicity (perioral numbness, metallic taste, seizures) in mother. Postoperative assessment of neonatal neurobehavioral status if high doses used near delivery. |
| Fertility Effects | No known effect on fertility in humans. Animal studies show no impairment of fertility at doses up to 2-3 times the maximum recommended human dose. |