What it's for (Indications)
- Etomidate is primarily indicated for the rapid induction of general anesthesia, particularly in clinical scenarios where the maintenance of hemodynamic stability is paramount.
- Its distinct pharmacological profile, characterized by minimal effects on myocardial contractility, heart rate, and vascular tone, renders it an agent of choice for patients with pre-existing cardiovascular compromise, including those with ischemic heart disease, severe valvular dysfunction, hypovolemia, or critical aortic stenosis.
- Furthermore, etomidate is often utilized for short-term sedation to facilitate brief diagnostic or therapeutic procedures requiring a swift onset and recovery, such as electrical cardioversion, rapid sequence intubation in emergency settings, or procedural sedation outside of the main operating theatre environment.
- The drug's rapid onset of action, typically within one minute, and its relatively short duration of effect make it well-suited for these acute applications where quick control of the airway and rapid emergence are desired.
- However, due to its propensity for adrenal suppression, prolonged or repeated administration for maintenance of anesthesia is generally avoided, limiting its primary use to the induction phase or very brief interventions.
Dosage Information
| Type | Guideline |
|---|---|
| Standard | Etomidate injection is intended for administration only by the intravenous route. The dose for induction of anesthesia in adult patients and in pediatric patients above 10 years of age will vary between 0.2 mg/kg and 0.6 mg/kg of body weight, and must be individualized. The usual induction dose 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 10 years of age; therefore, such use is not recommended. Geriatric patients may require reduced doses. Smaller increments of intravenous etomidate may be administered during short operative procedures to supplement subpotent anesthetic agents, such as nitrous oxide. Do not administer unless the solution is clear and the container is undamaged. Discard any unused portion. |
Safety & Warnings
Common Side Effects
- Common adverse reactions include transient venous pain on injection (reported in about 20% of patients, ranging from 1.
- 2% to 42%) and transient skeletal muscle movements, including myoclonus (noted in about 32% of patients).
- During recovery, other side effects may include high blood pressure, tachycardia (high heart rate), hallucinations (illusions or visions), psychomotor agitation (mood disorders), and mental confusion.
Serious Warnings
- Black Box Warning: Etomidate does not carry a formal FDA Black Box Warning. However, its profound and transient suppression of adrenocortical function warrants a serious warning. Etomidate inhibits 11-beta-hydroxylase, an enzyme essential for cortisol and aldosterone synthesis, leading to a dose-dependent reduction in plasma cortisol and aldosterone levels that can persist for several hours after a single induction dose. While a single dose may not result in clinically apparent adrenal insufficiency in healthy individuals, this effect is a critical concern in critically ill patients, especially those with sepsis, septic shock, or severe trauma. In these vulnerable populations, the inability to mount an appropriate physiological stress response due to impaired adrenal function can exacerbate critical illness and has been associated with increased morbidity and mortality, particularly with repeated doses or prolonged infusions. Clinicians must meticulously weigh the benefits of etomidate against the potential risks of adrenocortical suppression, particularly in patients under severe physiological stress or with compromised adrenal reserve. Vigilant monitoring for signs of adrenal insufficiency, such as refractory hypotension, is crucial, and alternative agents should be considered in high-risk patients.
- Pregnancy: There is positive evidence of risk; use only when no safer alternative exists or for a serious problem.
- Consult a doctor.
- Lactation: Not recommended for lactating females.
- Driving: Avoid driving as this medication may impair ability to drive.
- Precautions: Rapid administration (over a period of less than 60 seconds) or overdose may cause respiratory depression (slow and ineffective breathing).
How it Works (Mechanism of Action)
Etomidate is a short-acting, non-barbiturate hypnotic agent that exerts its potent central nervous system depressant effects primarily through the modulation of the gamma-aminobutyric acid (GABA)-A receptor complex. Specifically, etomidate acts as an allosteric modulator, binding to a distinct site on the GABA-A receptor, which is separate from the primary GABA binding site. This binding enhances the affinity of GABA for its receptor and, critically, increases the frequency of chloride channel opening. The consequent influx of chloride ions across the neuronal membrane leads to hyperpolarization of the neuron, effectively decreasing neuronal excitability and inhibiting synaptic transmission. This widespread suppression of neuronal activity within the central nervous system culminates in the rapid onset of hypnosis and loss of consciousness observed clinically. Unlike some other anesthetic agents, etomidate lacks intrinsic analgesic properties; therefore, it does not provide pain relief. Its rapid onset is attributable to its high lipid solubility, which facilitates swift distribution into the brain, while its short duration of action is due to rapid metabolism by hepatic microsomal enzymes and plasma esterases into inactive metabolites, allowing for prompt recovery post-administration.
Commercial Brands (Alternatives)
No other brands found for this formula.