Etomidate is a potent, ultra-short-acting, non-barbiturate intravenous hypnotic agent used for the induction of general anesthesia. It is characterized by rapid onset, short duration of action, and remarkable hemodynamic stability, making it particularly valuable in patients with compromised cardiovascular function, the elderly, and those in shock. It is a carboxylated imidazole derivative.
Adult: Induction: 0.2 to 0.6 mg/kg IV (typically 0.3 mg/kg). Average dose for a 70kg adult: 20mg (10ml) IV over 30-60 seconds. Titrate to effect.
Note: For IV use only. Must be administered by a trained anesthesiologist or critical care physician. Administer as a slow IV injection over 30-60 seconds into a large vein to minimize pain. Pre-treatment with an opioid (e.g., fentanyl) or lidocaine can reduce injection pain and myoclonus. Incompatible with many other IV drugs; flush line before and after administration.
Etomidate acts as a positive allosteric modulator of the gamma-aminobutyric acid type A (GABA-A) receptor. It enhances inhibitory neurotransmission by potentiating GABA-induced chloride ion influx, leading to neuronal hyperpolarization and depression of the central nervous system (CNS).
Pregnancy: Category C: Animal studies show adverse effects. Use only if potential benefit justifies potential fetal risk. Not recommended in first trimester. Can cross placenta.
Driving: Patients must be warned not to drive or operate machinery for at least 24 hours after administration.
| Fentanyl, Midazolam, Propofol | Potentiation of hypnotic and respiratory depressant effects. Dose reduction required. | Major |
| CNS Depressants (Alcohol, Opioids, Benzodiazepines) | Additive CNS depression. | Major |
| Succinylcholine | May increase incidence and severity of myoclonus. | Moderate |
| Ketamine | May provide hemodynamic stability but increased risk of emergence reactions. | Moderate |
| Drugs inhibiting CYP450 enzymes | Potential increase in etomidate levels (theoretical). | Minor |
Same composition (Etomidate (20mg/10ml)), different brands: