SUMMARY OF PRODUCT CHARACTERISTICS

1. NAME OF THE VETERINARY MEDICINAL PRODUCT

Antisedan 5 mg/ml solution for injection

2. QUALITATIVE AND QUANTITATIVE COMPOSITION

Each ml contains:

Active substance:

Atipamezole hydrochloride 5 mg

Excipients:

Qualitative composition of excipients and other constituents	Quantitative composition if that information is essential for proper administration of the veterinary medicinal product
Methyl parahydroxybenzoate (E 218)	1 mg/ml
Sodium chloride
Water for injections

Clear, colourless solution.

3. CLINICAL INFORMATION

3.1 Target species

Dogs and cats.

3.2 Indications for use for each target species

Atipamezole is indicated for the reversal of the sedative & analgesic effects of medetomidine or dexmedetomidine in dogs and cats. It also reverses all other effects of medetomidine or dexmedetomidine, such as cardiovascular and respiratory effects.

3.3 Contraindications

Do not use in cases of hypersensitivity to the active substance or to any of the excipients.

3.4 Special warnings

After administration of this veterinary medicinal product, the animals should be allowed to rest in a maximally quiet place.

When any combination of butorphanol or medetomidine or dexmedetomidine and ketamine have been used, atipamezole should not be used to reverse the effect in dogs.

3.5 Special precautions for use

Special precautions for safe use in the target species:

With the exception of those drugs mentioned within the SPC, the concurrent use of drugs affecting the CNS is not recommended.

The veterinary medicinal product should not be administered within 30-40 minutes of the administration of ketamine in cats. If the effect of the alpha-2 agonist is eliminated earlier, the residual effect of ketamine may cause convulsions.

Special precautions to be taken by the person administering the veterinary medicinal product to animals

Due to the potent pharmacological activity of atipamezole, contact with skin or mucosal membranes should be avoided. Personal protective equipment consisting of impervious gloves should be worn when administering the veterinary medicinal product. Care should be taken to avoid accidental self-injection. In case of accidental self-injection, seek medical advice immediately and show the package leaflet or the label to the physician. Do not drive. The patient should not be left unattended. In case of accidental spillage, wash the affected area immediately with clean running water. Seek medical attention if irritation persists. In case of accidental ingestion, seek medical advice immediately and show the package leaflet or the label to the physician.

Special precautions for the protection of the environment:

Not applicable.

3.6 Adverse events

Target species: Dogs and cats

Very rare (<1 animal / 10,000 animals treated, including isolated reports):

Behavioural disorders Hyperactivity Cardio-vascular system disorders Tachycardia Digestive tract disorders Diarrhoea Increased salivation Vomiting Respiratory tract disorders Panting

In dogs a transient hypotensive effect has been observed during the first ten minutes post-injection.

In cats, when using low doses to partially reverse the effects of medetomidine or dexmedetomidine, the possibility of hypothermia (even when aroused from sedation) should be guarded against.

Reporting adverse events is important. It allows continuous safety monitoring of a veterinary medicinal product. Reports should be sent, preferably via a veterinarian, to either the marketing authorisation holder or its local representative or the national competent authority via the national reporting system. See the package leaflet for respective contact details.

3.7 Use during pregnancy, lactation or lay

The safety of the veterinary medicinal product has not been established during pregnancy or lactation. The use is not recommended during pregnancy or lactation. 3.8 Interaction with other medicinal products and other forms of interaction

No harmful interactions have been identified in clinical trials, however concurrent use of those drugs affecting the CNS is not recommended apart from those in the SPC.

3.9 Administration routes and dosage

For intramuscular injection.

Dogs: The optimal dose of atipamezole in micrograms per kilogram is five times that of the previous medetomidine dose or 10 times the dexmedetomidine dose. The dose of the veterinary medicinal product in millilitres is the same as that of medetomidine 1 mg/ml or dexmedetomidine 0.5 mg/ml dose. The dose of the veterinary medicinal product in millilitres is one fifth (1/5) of the dose volume of dexmedetomidine 0.1 mg/ml. When medetomidine or dexmedetomidine have been used with or without butorphanol as a premedicant to thiopentone-halothane anaesthesia in dogs, or as premedicant to propofol anaesthesia in dogs, the product may be administered in the post-operative phase to reverse the effects of medetomidine or dexmedetomidine and hasten recovery.

Cats: The optimal dose of atipamezole in micrograms per kg is two-and-a-half times that of the previous medetomidine dose or five times the dexmedetomidine dose. The dose of the veterinary medicinal product in millilitres is half of that of medetomidine 1 mg/ml or dexmedetomidine 0.5 mg/ml dose and one tenth (1/10) of dexmedetomidine 0.1 mg/ml dose.

Example dosages:

Dogs:

Medetomidine dosage	Dexmedetomidine 0.5 mg/ml dosage	Dexmedetomidine 0.1 mg/ml dosage	Antisedan dosage
40 mcg/kg	20 mcg/kg	20 mcg /kg	200 mcg/kg
= 0.4 ml/10 kg	= 0.4 ml/10 kg	= 2.0 ml/10 kg	= 0.4 ml/10 kg

Cats:

Medetomidine dosage	Dexmedetomidine 0.5 mg/ml dosage	Dexmedetomidine 0.1 mg/ml dosage	Antisedan dosage
80 mcg/kg	40 mcg/kg	40 mcg/kg	200 mcg/kg
= 0.4 ml/5 kg	= 0.4 ml/5 kg	= 1.2 ml/3 kg*	= 0.2 ml/5kg 0.12 ml/3kg

* For cats weighing over 3 kg, dexmedetomidine 0.5 mg/ml is recommended. The dose in micrograms per kg should not exceed four times that of the previously administered medetomidine or eight times that of dexmedetomidine.

When cats have been anaesthetised with medetomidine or dexmedetomidine, with or without butorphanol, and ketamine, the veterinary medicinal product may be administered to reverse the effects of medetomidine or dexmedetomidine and so speed recovery from anaesthesia. The veterinary medicinal product dosage in this instance is the same as that used for recovery after single administration of medetomidine or dexmedetomidine; however, the veterinary medicinal product should not be administered prior to 30 to 40 minutes following ketamine administration.

3.10 Symptoms of overdose (and where applicable, emergency procedures and antidotes)

Transient over-alertness and tachycardia may be observed after a possible overdosage.

Over-alertness in the cat is best handled by minimising external stimuli.

3.11 Special restrictions for use and special conditions for use, including restrictions on the use of antimicrobial and antiparasitic veterinary medicinal products in order to limit the risk of development of resistance

Not applicable.

3.12 Withdrawal periods

Not applicable

4. PHARMACOLOGICALINFORMATION

4.1 ATCvet code: QV03AB90

4.2 Pharmacodynamics

Atipamezole is a selective a-2 adrenoceptor antagonist which is capable of reversing the sedative and analgesic effects of medetomidine or dexmedetomidine in dogs and cats. It also reverses all other effects of medetomidine or dexmedetomidine, such as cardiovascular and respiratory effects.

4.3 Pharmacokinetics

Atipamezole is quickly absorbed and is generally administered 15 - 60 minutes after the medetomidine or dexmedetomidine.

5. PHARMACEUTICAL PARTICULARS

5.1 Major incompatibilities

In the absence of compatibility studies, this veterinary medicinal product must not be mixed with other veterinary medicinal products.

5.2 Shelf life

Shelf life of the veterinary medicinal product as packaged for sale: 3 years. Shelf life after first opening the immediate packaging: 3 months.

5.3 Special precautions for storage

Do not store above 25°C.

Protect from light.

Following withdrawal of the first dose, use the product within 3 months.

5.4 Nature and composition of immediate packaging

Colourless glass type I vial containing 10 ml.

Glass (Type I) injection vial of 10 ml with grey bromobutyl rubber stopper with a fluorinated polymer coating.

5.5 Special precautions for the disposal of unused veterinary medicinal product or waste materials derived from the use of such products

Medicines should not be disposed of via wastewater.

Use take-back schemes for the disposal of any unused veterinary medicinal product or waste materials derived thereof in accordance with local requirements and with any national collection systems applicable to the veterinary medicinal product concerned.

6. NAME OF THE MARKETING AUTHORISATION HOLDER

Orion Corporation

7. MARKETING AUTHORISATION NUMBER

Vm 06043/4004

8. DATE OF FIRST AUTHORISATION

26 September 1989

9. DATE OF THE LAST REVISION OF THE SUMMARY OF THE PRODUCT CHARACTERISTICS

August 2026

10. CLASSIFICATION OF VETERINARY MEDICINAL PRODUCT

Veterinary medicinal product subject to prescription.

Find more product information by searching for the ‘Product Information Database’ on www.gov.uk.

Approved: 02 September 2026