Etomidate

Emergency & Prehospital

• Rapid sequence intubation induction: especially useful with hypotension, shock or limited cardiac reserve. Pair it with a neuromuscular blocker (see RSI).
• Head injury or raised intracranial pressure needing intubation: cerebral blood flow and ICP drop briefly. Blood pressure is largely spared.

ED / ICU / Transport

• Induction of general anesthesia (FDA-labeled): it fits where hemodynamic stability is the priority, such as severe cardiovascular disease
• Brief procedural sedation: for example electrical cardioversion or joint reduction. The ACEP clinical policy considers it safe for ED procedural sedation in adults, with weaker evidence in children. It is off-label, and whether you can use it depends on your credentials.

Other Uses

• Supplementation of subpotent anesthetics (FDA-labeled, adults): for example nitrous oxide during maintenance of anesthesia for short operative procedures
• Severe hypercortisolism (Cushing syndrome): a low-dose ICU infusion that shuts down cortisol synthesis. Off-label, and for specialists only.

Doses vary by protocol; follow local protocols and medical direction.

Available Forms

• 2 mg/mL in 10 mL (20 mg) single-dose vial: the one most EMS and transport services stock
• 2 mg/mL in 20 mL (40 mg) single-dose vial
• Vehicle: 35% propylene glycol (pH about 6). IV use only. Outside the US, a lipid-emulsion product is on the market, and it causes less injection pain.

Adult Dosing

Pediatric Dosing

Preparation & Administration

• Dilution: None. Draw up the 2 mg/mL solution undiluted. Do not use if cloudy or discolored.
• Push rate: over 30–60 sec (label). Push it fast, and you can cause hypotension.
• Line: a big proximal vein, such as the antecubital, hurts less than a hand or wrist vein. Flush before and after.
• IO: not a labeled route. Use it only where local protocol allows.
• Sequence: there is no analgesia at all. Plan post-intubation sedation and analgesia before you push.

Contraindications

• Known hypersensitivity to etomidate. It is the only US-labeled contraindication.
• Lipid-emulsion formulation (ex-US, e.g., Etomidate-Lipuro): soya or peanut allergy also rules it out (UK label)
• Prolonged infusion or repeated dosing for ICU sedation: not intended by the label. Adrenal suppression builds up with each dose.
• Children with sepsis or septic shock (relative). The 2026 Surviving Sepsis Campaign pediatric guideline suggests against it.

Precautions

• Adult septic shock: a single induction dose is acceptable. In the 2025-26 RSI trial (2,365 adults), 28-day in-hospital death was 29.1% with etomidate and 28.1% with ketamine. The adjusted difference was -0.8 points, favoring ketamine (95% CI -4.5 to 2.9, not significant). Cardiovascular collapse was less with etomidate, at 17.0% vs 22.1%. Do not use it for infusions or repeat dosing.
• Adrenal insufficiency or chronic corticosteroid use: cortisol synthesis stays blocked for hours. Continue steroids, or give stress-dose steroids per protocol.
• Hypovolemia, trauma, older adults with hypertension: the label data here are thin. BP, heart rate and cardiac index can all fall. Use the reduced dose.
• Acute porphyrias (hereditary disorders of heme synthesis): porphyrogenic in animal studies. The UK label says avoid it unless there is no safer alternative. The US label does not address porphyria.
• Painful stimulation: it gives no analgesia, and it does not blunt the laryngoscopy pressor response.
• Pregnancy, labor and delivery: the label does not recommend obstetric use, because the data are insufficient. See Special Populations.

Hold / Reassess If

• No one present can intubate or ventilate: do not give
• SBP <90 mmHg or MAP <65 mmHg before induction: resuscitate first (fluids, blood, vasopressor), then use the reduced dose
• SpO₂ <90% despite preoxygenation: optimize oxygenation (positive pressure) before induction where time allows

Common

• Myoclonus and other involuntary muscle movements: about 32% (range 23–63%) in the label. They show no EEG seizure activity.
• Injection pain: about 20%, and more often in small hand or wrist veins
• Brief apnea: 5–90 sec, after a brief spell of hyperventilation
• Nausea and vomiting after recovery
• Hiccups, snoring

Serious / Life-Threatening

Overdose & Toxicity Management

• Cause: pushing too fast, or pushing again and again. A rapid injection may drop BP.
• Management: stop the drug, secure the airway, give oxygen and ventilate; treat hypotension.
• No antidote: supportive care is all there is.

Clinically Significant Interactions

IV Compatibility

• Premedication: compatible with commonly used pre-anesthetic drugs (label). The label gives no admixture data.
• Administration: push undiluted into a free-flowing IV of NS or LR; do not mix in the same syringe with other drugs; flush before and after.
• Verify with an institutional compatibility resource.

• Pediatrics: the label does not recommend induction under 10 years, because the data are inadequate. See the Pediatric Dosing table. Avoid it in children with sepsis or septic shock (2026 Surviving Sepsis Campaign pediatric guideline, unchanged from 2020). Under 3 years, repeated or prolonged (>3 hr) anesthetic exposure carries the FDA developing-brain warning. Necessary anesthesia should not be withheld.
• Pregnancy: there are no adequate human studies. In animals, pup survival dropped, partly at doses below the human induction dose, and no malformations were seen. The label does not recommend use in labor and delivery, cesarean delivery included. The FDA anesthetic-neurotoxicity warning also covers repeated or lengthy (>3 hr) exposure in the third trimester. Do not withhold necessary anesthesia. In an airway emergency, choose the induction agent with the anesthesia or obstetric team, and do not delay airway care.
• Lactation: etomidate passes into breast milk, but only in small amounts. After one induction dose, colostrum levels were undetectable by 4 hr. LactMed says no waiting period is needed. Breastfeeding can resume once the mother has recovered enough from anesthesia to nurse. If other anesthetic drugs were given, follow the advice for the most restrictive one. The labels take a more cautious line. The US label advises caution. The UK label advises pausing for 24 hr and discarding that milk.
• Older Adults: use lower doses. Initial distribution volume and clearance are both reduced. BP, heart rate and cardiac index may fall, especially with hypertension (label).
• Renal Impairment: the label has no dose adjustment. Less protein binding means more free drug, so lower doses may be needed. Consider the low end of the range (0.2 mg/kg), as in older adults. The label notes the drug is largely cleared by the kidneys. Adverse reactions may be more likely when renal function is impaired.
• Hepatic Impairment: the label has no dose adjustment. In cirrhosis, clearance does not change. Distribution volume and half-life both grow, and protein binding drops, so lower doses may be needed. Consider the low end of the range (0.2 mg/kg).
• Obesity / Dosing Weight: dose on total body weight when BMI is under 40 kg/m². At BMI 40 kg/m² or more, use total or adjusted body weight. Expert review supports this, but the evidence is observational.
• Critically Ill / Septic Adults: one dose suppresses cortisol. In the 2025-26 RSI trial, in-hospital death by 28 days was similar to ketamine. Keep it to a single dose, and see Precautions.

• Scope: Paramedic RSI, critical-care transport, ED and ICU induction. It varies by state and agency protocol.
• Storage & Stability: 20–25 °C (68–77 °F) controlled room temperature (label). Not a controlled substance.
• Carried Concentration: only one strength, 2 mg/mL. On the RSI checklist, state the dose in mg and mL.
• Before Induction: resuscitate first (fluids or blood, vasopressor ready), preoxygenate, and have post-intubation sedation drawn up.
• Handoff Essentials: time and dose of etomidate (mg and mg/kg), paralytic and time, BP response, sedation started, and that etomidate was given (relevant if shock becomes refractory).

Mechanism of Action

• GABA-A positive allosteric modulator (imidazole derivative). It enhances chloride inhibition, and that brings hypnosis and amnesia with no analgesia.
• Little effect on sympathetic tone, myocardial contractility or histamine release. So BP and heart rate are largely preserved.
• Inhibits adrenal 11β-hydroxylase: cortisol and aldosterone synthesis stay blocked for hours, at concentrations lower than those needed for hypnosis.
• Cerebral effects: cerebral blood flow falls 20–30% (label). ICP falls moderately for several minutes. Intraocular pressure falls modestly.

Pharmacokinetics

• Half-life: terminal phase about 75 min in the label, and 2.9–5.5 hr in later studies. Hypnosis ends as the drug redistributes.
• Metabolism: ester hydrolysis in the liver (and some plasma) makes an inactive carboxylic acid. Hepatic extraction is high.
• Elimination: about 75% of a dose in urine within 1 day; <2% unchanged.
• Protein binding: about 75%, bound to albumin. It is lower in older adults, renal failure and cirrhosis.

Generic Name

Etomidate (etomidate injection, USP)

Brand Names

Amidate (US); generics. Outside the US: Hypnomidate; Etomidate-Lipuro (lipid emulsion)

Pharmacologic Class

Imidazole-derivative non-barbiturate hypnotic; GABA-A positive allosteric modulator

Therapeutic Class

IV general anesthetic induction agent

Controlled Substance

Not controlled

ISMP High-Alert

Yes: ISMP high-alert medication (general anesthetic agents, IV)

Look-Alike / Sound-Alike

None commonly reported