Etomidate
Etomidate is a short-acting intravenous anaesthetic agent used for the induction of general anaesthesia and sedation for short procedures such as reduction of dislocated joints, tracheal intubation, and cardioversion.
Mechanism of effect
Etomidate is a carboxylated imidazole compound that appears to depress CNS function via enhancement ofgamma-aminobutyric acid (GABA) neurotransmission.Like most anesthetic agents, etomidate produces a transient reduction in cerebral blood flow with a resultant reduction in cerebral oxygen utilization.
Pharmacodynamic
Etomidate is an imidazole compound that appears to depress CNS function via GABA. Duration of action is intermediate between thiopental and methohexital, and recovery from a single dose is rapid with little residual depression. Like the barbiturates and propofol, etomidate is does not induce analgesia.
Pharmacokinetics
At the typical dose, anesthesia is induced for about 5–10 minutes, though the half-life of drug metabolism is about 75 minutes, because etomidate is redistributed from the plasma to other tissues .
Onset of action : 30–60 seconds
Peak effect : 1 minute
Duration : 3–5 minutes; terminated by redistribution
Distribution : Vd: 2–4.5 L/kg
Protein binding : 76%
Metabolism : Hepatic and plasma esterases
Half-life distribution : 2.7 minutes
Half-life redistribution : 29 minutes
Half-life elimination : 2.9 to 5.3 hours
Excretion : 75% renal (80% as metabolite)
Dosage
The dose for induction of anesthesia in adult patients and in pediatric patients above the age of ten (10) years will vary between 0.2 mg/kg and 0.6 mg/kg of body weight, and it must be individualized in each case .
The usual dose for induction in these patients is 0.3 mg/kg, injected over a period of 30 to 60 seconds. There are inadequate data to make dosage recommendations for induction of anesthesia in patients below the age of ten (10) years; therefore, such use is not recommended. Geriatric patients may require reduced doses of Etomidate .
Drug contraindications
hypersensitivity to this drugAlerts
- Because of the hazards of prolonged suppression of endogenous cortisol and aldosterone production, this formulation is not intended for administration by prolonged infusion .
- Pediatric Neurotoxicity : Published animal studies demonstrate that the administration of anesthetic and sedation drugs that block NMDA receptors and/or potentiate GABA activity increase neuronal apoptosis in the developing brain and result in long-term cognitive deficits when used for longer than 3 hours .
- Geriatric Use : Clinical data indicates that Etomidate may induce cardiac depression in elderly patients, particularly those with hypertension.This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection and it may be useful to monitor renal function .
Points of recommendation
- Studies conducted in young animals and children suggest repeated or prolonged use of general anesthetic or sedation drugs in children younger than 3 years may have negative effects on their developing brains. Discuss with your doctor the benefits, risks, and timing and duration of surgery or procedures requiring anesthetic and sedation drugs .
- Advise patient to avoid driving or other activities requiring alertnessfor 24 hr following administration .
- Advise patient to avoid alcohol or other CNS depressants without the advice of ahealthcare professional for 24 hr following administration .
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