Target species
Horses.
Indications for use, specifying the target species
For short term relief of pain associated with colic of gastrointestinal tract origin. For information on the onset and duration of analgesia that can be expected following treatment, see pharmacodynamic properties.
For sedation in combination with certain α2-adrenoceptor agonists.
Contraindications
Butorphanol – as a sole agent and in any combination:
Do not use in horses with a history of liver or kidney disease.
Do not use in case of known hypersensitivity to the active substance or to any of the excipients.
Do not use in cases of cerebral injury or organic brain lesions (e.g. lesions following cranial trauma) and in animals with obstructive respiratory diseases, heart dysfunction or spastic convulsions.
Butorphanol / detomidine hydrochloride combination:
The combination should not be used in pregnant animals.
Do not use the combination in horses with a pre-existing cardiac dysrhythmia or bradycardia.
Do not use in horses with emphysema due to a possible depressive effect in the respiratory system.
Butorphanol / romifidine combination:
Do not use during the last month of pregnancy.
Butorphanol / xylazine combination:
The combination should not be used in pregnant animals.
Any reduction in gastrointestinal motility caused by butorphanol (see adverse reactions) may be enhanced by the concomitant use of α2-adrenoceptor agonists. Consequently, such combinations should not be used in cases of colic associated with impaction.
Special warnings for each target species
None.
Special precautions for use
Special precautions for use in animals
Safety and efficacy of butorphanol in foals have not been established. In foals use the product only according to the benefit/risk assessment by the responsible veterinarian.
Due to its antitussive properties, butorphanol may lead to an accumulation of mucous in the respiratory tract. Therefore, in animals with respiratory diseases associated with increased mucous production or in animals that are being treated with expectorants, butorphanol should only be used on the basis of a risk-benefit analysis by the responsible veterinarian.
The use of the product at the recommended dose may lead to transient ataxia and/or excitement. Therefore, to prevent injuries in patient and people, the location for the treatment should be chosen carefully.
Butorphanol / detomidine hydrochloride combination:
Routine cardiac auscultation should be performed prior to use in combination with detomidine.
Special precautions to be taken by the person administering the veterinary medicinal product to animals
Direct contact with skin or eye of the user should be avoided since the product might induce irritation and sensitization. Accidental spillage on the skin should be washed immediately with soap and water. When the product comes into contact with the eyes, rinse immediately with plenty of water.
Care should be taken when handling the product to avoid self-injection. In case of accidental self-injection, seek medical advice immediately and show the package insert or the label to the physician, and DO NOT DRIVE, since drowsiness, nausea and dizziness may occur. Effects can be reversed by the administration of an opioid antagonist.
Adverse reactions
Butorphanol may cause the following side-effects:
- Excitatory locomotor effects (pacing)
- Mild sedation (may occur following the administration of butorphanol as a sole agent)
- Ataxia
- Reduction in gastrointestinal motility
- Depression of cardiovascular system
Use during pregnancy, lactation or lay
The safety of this product has not been investigated in the target species during pregnancy and lactation. The use of butorphanol during pregnancy and lactation is not recommended.
For information on use in combination with α2-adrenoceptor agonists, see contraindications
Interaction with other medicinal products and other forms of interaction
See special precautions for use.
Butorphanol may be used in combination with other sedatives such as α2-adrenoceptor agonists (e.g. romifidine, detomidine, xylazine) where synergistic effects can be expected. Therefore, an appropriate reduction in dose is necessary when used concomitantly with such agents.
Because of its antagonist properties at the opiate mu receptor, butorphanol may inhibit the analgesic effect in animals, which have already received pure opioid mu agonists (morphine/oxymorphine).
Because of the antitussive properties of butorphanol, it should not be used in combination with an expectorant, as this may lead to an accumulation of mucous in the airways.
The combination of butorphanol and α2-adrenoceptor agonists should be used with caution in animals with cardiovascular disease. The concurrent use of anticholinergic drugs, e.g. atropine should be considered.
Amount(s) to be administered and administration route
For intravenous administration only.
For analgesia:
Dose rate: 100 μg butorphanol per kg bodyweight (BW) (equivalent to 1 ml for 100 kg BW), by intravenous injection. Butorphanol is intended for use where short duration analgesia is required. The dose may be repeated as required. The need for and timing of repeat treatment will be based on clinical response. For information on the onset and duration of analgesia see pharmacodynamic properties. For cases where longer duration analgesia is likely to be required, an alternative therapeutic agent should be used.
For sedation in combination with detomidine hydrochloride:
A dose rate of 12 μg detomidine hydrochloride per kg BW should be given intravenously followed within 5 minutes by a dose rate of 25 μg butorphanol per kg BW (equivalent to 0.25 ml for 100 kg BW) intravenously.
For sedation in combination with romifidine:
A dose of 40-120 μg romifidine per kg BW followed within 5 minutes by a dose rate of 20 μg butorphanol per kg BW (equivalent to 0.2 ml for 100 kg BW) should be administered intravenously.
For sedation in combination with xylazine:
A dose rate of 500 μg xylazine per kg BW followed immediately by a dose of 25-50 μg butorphanol per kg BW (equivalent to 0.25-0.5 ml per 100 kg) should be administered intravenously.
Overdose
The main sign of overdose is respiratory depression which can be reversed with an opioid antagonist (naloxone). Other possible signs of overdose in the horse include restlessness/excitability, muscle tremor, ataxia, hypersalivation, decrease of gastrointestinal motility and seizure.
Withdrawal periods
Meat and offal: zero days.
Milk: zero days.