Atipamezole: veterinary dose and monograph

At a glance

Drug class

Veterinary drug

Also known as

Antisedan, Revertor

Species with doses

Dogs, Cats, Cattle, Horses, Goats, Sheep, Birds, Rabbits, Ferrets and Camelids

General dose range

0.05–0.2 mg/kg IM once (reversal) — check the species tables for the indication

Routes

IM, IV

Last reviewed

1 October 2026

Indications

• Reversal of dexmedetomidine / medetomidine sedation
• Reversal of xylazine / detomidine over-sedation
• Shortening recovery in sick or geriatric patients

Atipamezole dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

Dogs

• Reverse dexmedetomidine / medetomidine: Papich 5e and Plumb’s p.121 (label): inject the SAME VOLUME as the dexmedetomidine or medetomidine given, IM (or IV) — with label sedative doses this is 0.32 mg/kg for a 4 kg dog, 0.23 mg/kg for 11 kg and about 0.14 mg/kg for 45 kg (smaller dogs at the upper end). In mg this is 5× the medetomidine dose or 10× the dexmedetomidine dose, so scale down if a lower sedative dose was used. Plumb’s: dexmedetomidine reversal 0.2 mg/kg IM or IV (Teixeira Neto 2009); if IV more than 45 min after medetomidine, half the volume. The 0.05 mg/kg dose is for amitraz toxicity (separate row).
• Amitraz toxicity: Plumb’s p.121 (Hugnet 1996; Papich 2009): 50 µg/kg IM; repeat every 4–6 h because amitraz outlasts atipamezole.

Cats

• Reverse dexmedetomidine / medetomidine: Plumb’s p.121: dexmedetomidine reversal 0.2 mg/kg IM or IV (Teixeira Neto 2009); after medetomidine combinations give an equal volume IM (Ko 2005). Papich 5e: same volume as the dexmedetomidine/medetomidine given (in mg, 10× the dexmedetomidine or 5× the medetomidine dose). If ketamine was part of the protocol, wait until it has worn off before reversing.

Cattle

• Reverse alpha-2 agonist: Plumb’s p.121 (Haskell 2005): cattle, camelids, sheep and goats 0.02–0.1 mg/kg IV to effect. Extra-label — obtain a FARAD withdrawal.

Horses

• Reverse detomidine / dexmedetomidine: Papich 5e: horses 60–80 µg/kg IV (range up to 150 µg/kg); typically 100 µg/kg IV to reverse detomidine. Reversal removes alpha-2 analgesia — ensure other analgesia is in place. (= 0.06–0.08 mg/kg, up to 0.15 mg/kg; 0.1 mg/kg for detomidine reversal.)

Goats

• Reverse alpha-2 agonist: Plumb’s p.121: small ruminants and camelids 0.1–0.2 mg/kg slow IV or IM (Snyder 2009), or 0.02–0.1 mg/kg IV to effect (Haskell 2005). After ketamine or Telazol induction wait 30–60 min before reversing.

Sheep

• Reverse alpha-2 agonist: Plumb’s p.121: small ruminants and camelids 0.1–0.2 mg/kg slow IV or IM (Snyder; Wolff 2009), or 0.02–0.1 mg/kg IV to effect (Haskell 2005). After ketamine or Telazol induction wait 30–60 min before reversing.

Buffalo

No buffalo-specific doses are on file, so buffalo are dosed as cattle.

• Reverse alpha-2 agonist: Plumb’s p.121 (Haskell 2005): cattle, camelids, sheep and goats 0.02–0.1 mg/kg IV to effect. Extra-label — obtain a FARAD withdrawal.

Birds

• Reverse alpha-2 agonist: Plumb’s p.121 (Clyde & Paul-Murphy 2000): 0.5 mg/kg IM to reverse xylazine, detomidine and other alpha-2 agonists.

Rabbits

• Reverse medetomidine / dexmedetomidine: Plumb’s p.121 (Vella 2009): rabbits 0.5 mg/kg IM or SC, or 0.25 mg/kg IV.

Ferrets

• Reverse dexmedetomidine / medetomidine: Carpenter's 6th ed (Ferret table): 0.4 mg/kg IM, or 1 mg/kg SC/IV/IP. Rule of thumb: give the same volume SC/IM as the medetomidine, or 5× the medetomidine / 10× the dexmedetomidine dose (in mg). Give IM (not rapid IV) to avoid excitation.

Camelids

• Reverse alpha-2 agonist: Plumb’s p.121 (Wolff 2009): camelids 0.1–0.2 mg/kg slow IV or IM; wait 30–60 min after ketamine/Telazol induction before reversing.

Contraindications

Not for routine IV use (risk of excitation, hypotension, tachycardia — give IM). Reversal also reverses analgesia — provide alternative analgesia first.

Adverse effects

• Transient excitation / vocalisation if given too fast or IV
• Brief tachycardia / hypotension
• Re-sedation possible if the agonist outlasts the antagonist

Drug interactions

• The manufacturer states that information on use with drugs OTHER than medetomidine is lacking — take care with any combination
• Alpha-2 adrenergic agonists (detomidine, clonidine, brimonidine, xylazine, amitraz): atipamezole reduces their effects, both toxic and therapeutic — this is the basis of its use as an antidote in amitraz toxicosis
• Alpha-1 adrenergic blockers (e.g. prazosin): although a relatively specific alpha-2 blocker, atipamezole can partially block alpha-1 receptors and reduce the effect of prazosin

Toxicity and overdose

Plumb's p.121: dogs receiving up to 10x the listed dose tolerated it without major effects. Dose-related effects on overdose were panting, excitement, trembling, vomiting, soft or liquid faeces, scleral vasodilatation and some muscle injury at the IM site. Specific overdose therapy is generally not necessary. The clinically important hazard is not toxicity but the REVERSAL ITSELF: it abolishes analgesia along with sedation and can be abrupt — animals must be observed and protected from self-harm or from harming others.

Clinical pearls

• Standard rule of thumb: give the same volume IM as the dexmedetomidine / medetomidine you administered
• Always give IM, not IV — rapid reversal causes excitation and cardiovascular swings
• Reversal abolishes alpha-2 analgesia — make sure another analgesic is on board before reversing

Mechanism of action

Plumb's p.120: atipamezole competitively inhibits ALPHA-2 adrenergic receptors, acting as a reversal agent for alpha-2 agonists. Net effects are to reduce sedation, decrease blood pressure, increase heart and respiratory rates, and REDUCE ANALGESIA. Labelled to reverse medetomidine and dexmedetomidine, and potentially useful against other alpha-2 agonists — amitraz, xylazine, clonidine, tizanidine, brimonidine. It also antagonises the diuretic action of xylazine in dogs (Talukder et al. 2009). After IM administration in dogs peak plasma levels occur at about 10 minutes; it is metabolised in the liver, excreted in urine, and has a plasma elimination half-life of roughly 2–3 hours — which can be SHORTER than the agonist it reversed, hence the risk of re-sedation.

Formulations and products

• Antisedan 5 mg/mL injection

Before you use this dose

Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

Other hormones, emergency drugs, supplements and other drugs

• Altrenogest
• Aminophylline
• Amitriptyline
• Atracurium
• Atropine Sulfate
• Azathioprine
• B-Complex Injection (B1 + B6 + B12)
• Bethanechol

Frequently asked questions