# Atipamezole: veterinary dose and monograph

> Atipamezole is a veterinary drug. Selective alpha-2 adrenergic ANTAGONIST — the specific reversal agent for dexmedetomidine, medetomidine, xylazine and detomidine. Indications include reversal of dexmedetomidine / medetomidine sedation; reversal of xylazine / detomidine over-sedation; shortening recovery in sick or geriatric patients. This monograph lists 11 reference doses for dogs, cats, cattle, horses, goats and sheep and 4 more species, each with route, frequency and source, plus meat and milk withdrawal periods for food animals.

Source: https://vetmasterji.com/drugs/atipamezole · Last reviewed: 2026-10-01

## 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

*Atipamezole doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Reverse dexmedetomidine / medetomidine | 0.14–0.32 mg/kg | IM | once | — |
| Amitraz toxicity | 0.05 mg/kg | IM | repeat q4–6h as needed | — |

- 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

*Atipamezole doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Reverse dexmedetomidine / medetomidine | 0.2 mg/kg | IM | once | — |

- 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

*Atipamezole doses for cattle*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Reverse alpha-2 agonist | 0.02–0.1 mg/kg | IV | to effect | — | Withdrawal NOT established — treat as extra-label |

- 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

*Atipamezole doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Reverse detomidine / dexmedetomidine | 0.06–0.1 mg/kg | IV | once | — |

- 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

*Atipamezole doses for goats*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Reverse alpha-2 agonist | 0.1–0.2 mg/kg | IM | once (slow IV or IM) | — | Withdrawal NOT established — treat as extra-label |

- 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

*Atipamezole doses for sheep*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Reverse alpha-2 agonist | 0.1–0.2 mg/kg | IM | once (slow IV or IM) | — | Withdrawal NOT established — treat as extra-label |

- 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.

*Atipamezole doses for buffalo*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Reverse alpha-2 agonist | 0.02–0.1 mg/kg | IV | to effect | — | Withdrawal NOT established — treat as extra-label |

- 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

*Atipamezole doses for birds*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Reverse alpha-2 agonist | 0.5 mg/kg | IM | once | — |

- 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

*Atipamezole doses for rabbits*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Reverse medetomidine / dexmedetomidine | 0.25–0.5 mg/kg | IM | once | — |

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

### Ferrets

*Atipamezole doses for ferrets*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Reverse dexmedetomidine / medetomidine | 0.4–1 mg/kg | IM | once | — |

- 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

*Atipamezole doses for camelids*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Reverse alpha-2 agonist | 0.1–0.2 mg/kg | IM | once (slow IV or IM) | — |

- 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

> **Caution:** 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.

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## Frequently asked questions

### What is the dose of Atipamezole for dogs?

Reference doses for Atipamezole in dogs: 0.14–0.32 mg/kg IM once (Reverse dexmedetomidine / medetomidine); 0.05 mg/kg IM repeat q4–6h as needed (Amitraz toxicity). Confirm against the label and the patient before use.

### What is the dose of Atipamezole for cats?

Reference doses for Atipamezole in cats: 0.2 mg/kg IM once (Reverse dexmedetomidine / medetomidine). Confirm against the label and the patient before use.

### What is the dose of Atipamezole for cattle?

Reference doses for Atipamezole in cattle: 0.02–0.1 mg/kg IV to effect (Reverse alpha-2 agonist). Confirm against the label and the patient before use.

### What is the withdrawal period for Atipamezole?

Cattle, IV (Reverse alpha-2 agonist): Withdrawal NOT established — treat as extra-label; Goats, IM (Reverse alpha-2 agonist): Withdrawal NOT established — treat as extra-label; Sheep, IM (Reverse alpha-2 agonist): Withdrawal NOT established — treat as extra-label. Follow the product label and national regulations where they differ.

### When should Atipamezole not be used?

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

### What are the side effects of Atipamezole in animals?

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

## Sources

- Plumb's Veterinary Drug Handbook
- Carpenter's Exotic Animal Formulary 6th ed — Ferret restraint/anaesthetic agents (Table 11-5)
- Papich, Papich Handbook of Veterinary Drugs, 5th edition
- Carpenter, Exotic Animal Formulary

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