Action and Spectrum

Mechanism of action

It is a hypnotic anesthetic agent used for induction of anaesthesia. The etomidate’s action mechanism is by inhibiting the activity of the enzyme GABA-A receptor-chloride channel complex, which enhances the synaptic action of GABA, the primary inhibitory neurotransmitter in the central nervous system

Spectrum

It has a narrow spectrum of activity, primarily inducing hypnotic and sedative effects with minimal cardiovascular or respiratory depression. It has little effect on muscle tone and does not significantly impact blood pressure or heart rate. This makes etomidate a practical option for induction of anesthesia in specific high-risk patient populations, such as those with cardiovascular disease

Drug Interaction

Adverse Reaction

Frequency defined

>10%

Skeletal muscle movements

Adrenal suppression

Pain at the injection site

opsoclonus

1-10%

hiccups

<1%

Arrhythmias

HTN

Hypoventilation

Nausea/vomiting

Snoring

Apnea

Hyperventilation

Hypotension

Laryngospasm

Oxygen desaturation

Black Box Warning

Contraindication / Caution

Contraindications

• Hypersensitivity to the drug
• Severe hepatic impairment
• Myocardial depression
• Adrenal insufficiency
• Severe electrolyte disturbances

Caution

• Cardiovascular disease
• Chronic adrenal insufficiency
• Seizure disorders
• Electrolyte imbalances
• Patients with a history of alcohol or drug abuse
• Elderly patients and debilitated individuals

Pregnancy / Lactation

Pregnancy consideration: Insufficient data available

Lactation: Excretion of the drug in human breast milk is unknown

Pregnancy category:

Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester.

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women.

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.

Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.

Pregnancy consideration: Insufficient data available 

Lactation: Excretion of the drug in human breast milk is unknown 

Pregnancy category: 

Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester.   

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.    

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: There is no data available for the drug under this category. 

There is no data available for the drug under this category.

Pharmacology

Pharmacology

It is a non-barbiturate hypnotic used for the induction of anesthesia but does not have any analgesic effects. It is known for having minimal cardiovascular effects and for blocking 11-beta-hydroxylase, a key enzyme in steroidogenesis, which reduces plasma cortisol levels for up to 24 hours. Additionally, etomidate does not affect cardiac metabolism and does not cause depression in cardiac output, peripheral circulation, or pulmonary circulation.

Pharmacodynamics

The pharmacodynamics of etomidate is characterized by its rapid onset of action, brief duration of effect, and lack of significant respiratory or cardiovascular depression. It also has minimal effect on muscle tone. It does not significantly affect blood pressure or heart rate, making it a valuable option for the induction of anesthesia in specific high-risk patient populations.

Etomidate also blocks the steroidogenic enzyme 11-beta-hydroxylase, reducing cortisol production, which can help treat conditions such as Cushing’s syndrome (off-label use)

Pharmacokinetics

Absorption: It is rapidly absorbed after intravenous administration, with an onset of action within 60 seconds

Duration: The duration of effect is brief, lasting 3-5 minutes, due to redistribution from the central nervous system

Distribution: It is highly protein-bound (76%) and has a 2-4.5 L/kg volume distribution

Metabolism: It is metabolized by hepatic and plasma esterases

Elimination/Excretion: The drug is eliminated primarily in the urine as an inactive agent

Adminstartion

Administration

Intravenous administration

It is emphasized that the IV infusion should only be administered by healthcare professionals who have been trained in administering general anaesthetics and managing any complications that may arise during its administration.

Etomidate should be injected undiluted by direct IV injection over 30-60 seconds and should not be administered by prolonged IV infusion. It is recommended to inject the drug into a large forearm vein.

Finally, preadministration of lidocaine may be considered to minimize injection-site pain

Patient Information Leaflet

Patient information leaflet

Generic Name: etomidate

Pronounced: (ee-tuh-muh-date)

Why do we use etomidate?

It is a short-acting intravenous anesthetic agent to induce and supplement sub-potent anesthesia during short surgical procedures. It is administered intravenously and acts rapidly to induce a state of unconsciousness, allowing for the performance of surgical procedures. The short duration of effect and lack of significant respiratory or cardiovascular depression makes it a helpful option in specific patient populations.