Etomidate

What is this medication for?

• Anesthetic INDUCTION — alternative to thiopental/propofol, especially: preexisting cardiac dysfunction, head trauma, critically ill

How is it given?

This medication is normally given by your veterinary team (in clinic or hospital).

• Single-induction-dose cortisol suppression is real but transient; the rule "induction only, never infusion" is how the class earned its safety reputation (human ICU infusions caused adrenal crises historically).

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• Adrenocortical suppression (cortisol synthesis blockade — even single dose; dose-duration dependent) (The signature adverse — supplement glucocorticoids in critically ill patients; induction-only use)
• Myoclonus/twitching, vomiting (Reduced by pre-medication)
• Pain on injection (propylene glycol vehicle), hemolysis with high volumes (Vehicle effects)
• No analgesia (By design)

Worth a phone call to your veterinarian

• Any new symptom that worries you.

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• Trouble breathing, collapse, seizures, severe vomiting or diarrhea, facial swelling, or pale gums

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: Hypersensitivity
• has or has had: Impaired adrenocortical function; NOT for maintenance/CRI (adrenal suppression accumulates); MH-susceptible patients (may speed onset if another trigger present)

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • Other anesthetics/CNS depressants
  • Glucocorticoids

Storage and handling

into a vein use only; expensive especially in large dogs; not a controlled substance (handling ease).

Good to know

• The cardiac patient's induction drug: blood pressure preserved when propofol/thiopental would tank it — and the head-trauma patient's choice (↓ICP/CMRO₂) — paid for with a blocked adrenal axis.
• Single-induction-dose cortisol suppression is real but transient; the rule "induction only, never infusion" is how the class earned its safety reputation (human ICU infusions caused adrenal crises historically).
• TI 16 vs 3–5 for propofol/thiopental — the exam-friendly safety-margin trio.