Acepromazine

What is this medication for?

• Restraint aid, antiemetic (motion sickness), preanesthetic
• Sedation/restraint (see pearls: stallion penile-prolapse + intra-arterial risks)
• Tranquilizer/restraint (pregnant jills safe per Finkler; watch hypothermia/low blood pressure)

How is it given?

Give exactly as your veterinarian prescribed — never change the dose or stop on your own unless your veterinarian has told you to.

• No analgesic effect — never rely on it alone for painful procedures.
• Never treat acepromazine-induced low blood pressure with epinephrine — it will worsen low blood pressure via unopposed beta effects; use phenylephrine or fluids instead.
• Cannot always be relied upon as a sole restraint agent — effect can be overridden by strong stimuli, and it may increase startle/reactivity in aggressive dogs.

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

• Hypotension (Well-described, dose-related)
• Penile prolapse (Can persist ~2h, risk of permanent injury if untreated)
• ↓ tear production (Documented)
• Prolapse of nictitans (Reported)

Worth a phone call to your veterinarian

• Paradoxical CNS stimulation/aggression (Uncommon)

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

• Bradycardia, transient sinoatrial arrest (Common)

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

• has or has had: Cardiac disease, hypovolemia/shock, hepatic dysfunction; tetanus/strychnine toxicity (extrapyramidal interaction); MDR1-mutant dogs — reduce dose 25–50%; giant breeds/sighthounds more sensitive, terriers relatively resistant

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • Epinephrine, ephedrine
  • Organophosphates
  • Opiates
  • Metoclopramide
  • Propranolol, quinidine
  • Other CNS depressants

Storage and handling

Room temperature; standard injectable storage.

Good to know

• No analgesic effect — never rely on it alone for painful procedures.
• Never treat acepromazine-induced low blood pressure with epinephrine — it will worsen low blood pressure via unopposed beta effects; use phenylephrine or fluids instead.
• Cannot always be relied upon as a sole restraint agent — effect can be overridden by strong stimuli, and it may increase startle/reactivity in aggressive dogs.