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Clinical particulars
Target species
Dogs, cats and horses.
Indications for use
Dog:
As an analgesic:
- For relief of mild to moderate visceral pain.
As a sedative:
- For sedation, when used in combination with certain alpha2-adrenoceptor agonists (medetomidine).
As a premedicant prior to general anaesthesia:
- For use in combination with acepromazine to provide analgesia and sedation prior to induction of general anaesthesia. A dose-related reduction in the dose of induction-anaesthetic agent (propofol or thiopentone) is also provided.
- For premedication, give as the sole pre-anaesthetic agent.
As an anaesthetic:
- For anaesthesia, when used in combination with medetomidine and ketamine
Cat:
As an analgesic for the relief of moderate pain:
- For pre-operative use to provide analgesia during surgery.
- For post-operative analgesia after small surgical procedures.
As a sedative:
- For sedation when used in combination with certain alpha2-adrenoceptor agonists (medetomidine).
As an anaesthetic:
- For anaesthesia, when used in combination with medetomidine and ketamine, suitable for short painful anaesthetic procedures.
Horse:
As an analgesic:
- For the relief of moderate to severe abdominal pain associated with colic of gastrointestinal origin.
As a sedative:
- For sedation, given after the administration of certain alpha2-adrenoceptor agonists (detomidine, romifidine).
Contraindications
All target species:
Do not use in cases of hypersensitivity to the active substance or any of the excipients.
Do not use in animals with severe dysfunction of the liver or kidneys.
Do not use in animals with cerebral injury or organic brain lesions.
Do not use in animals with obstructive respiratory disease, heart dysfunction or spastic conditions.
Horse:
Butorphanol/detomidine hydrochloride combination:
Do not use in horses with a pre-existing cardiac dysrhythmia or bradycardia.
Do not use in cases of colic associated with impaction as the combination will cause a reduction in gastrointestinal motility.
Do not use in horses with emphysema due to a possible depressive effect on the respiratory system.
Do not use in pregnant mares.
Butorphanol/romifidine combination:
Do not use during the last month of pregnancy.
Special warnings for each target species
Butorphanol is intended for use where short duration analgesia (horse, dog) or short to medium duration analgesia (cat) is required (see Pharmacodynamic properties). In cases where longer duration analgesia is likely to be required, an alternative therapeutic agent should be used.
Marked sedation does not occur when butorphanol is used as a sole agent in cats.
In cats, individual response to butorphanol may be variable. In the absence of an adequate analgesic response, an alternative analgesic agent should be used.
In cats increasing of the dose will not increase intensity or duration of desired effects.
Special precautions for use in animals
All target species:
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, butorphanol should only be used according to a benefit-risk assessment by the responsible veterinary surgeon.
Prior to use of the product in combination with α2-adrenoreceptor agonists routine cardiac auscultation should be performed and the concurrent use of anticholinergic drugs, e.g. atropine should be considered.
The combination of butorphanol and an α2-adrenoceptor agonists should be used with caution in animals with mild to moderate dysfunction of the liver or kidney.
Take care when administering butorphanol to animals concurrently treated with other central nervous depressants (see Interactions).
The safety of the product in puppies, kitten and foals has not been established and therefore in these animals the product should only be used according to a benefit-risk assessment by the responsible veterinary surgeon.
Dog:
When administering as an intravenous injection, do not inject rapidly as a bolus.
In dogs with MDR1 mutation reduce dose by 25-50%
Cat:
Use of either insulin syringes or 1 ml graduated syringes is recommended.
Horse:
The use of the product at the recommended dose may lead to transient ataxia and/or excitement. Therefore, to prevent injuries, in the patient and people when treating horses, the location for the treatment should be chosen carefully.
Special precautions to be taken by the person administering the veterinary medicinal product to animals
Butorphanol has opioid activity.
The most frequent adverse effects of butorphanol in humans are drowsiness, sweating, nausea, dizziness and vertigo and these may occur following unintended self-injection. Care should be taken to avoid accidental injection/self-injection. If accidental self-injection occurs, seek medical advice immediately and show the package leaflet or the label to the physician. Do not drive. An opioid antagonist (e.g. naloxone) may be used as an antidote.
Wash any splashes from skin and eyes immediately.
Adverse reactions
All target species:
There may be some pain on intramuscular injection.
Sedation may be noted in treated animals.
Dog:
Respiratory and cardiac depression (as evidenced by a decrease in respiratory rate, development of bradycardia and a decrease in diastolic pressure) may occur (see Special precautions for use in animals). The degree of depression is dose-dependent. If respiratory depression occurs, naloxone may be used as an antidote. Moderate to marked cardiopulmonary depression may occur if butorphanol is given rapidly by intravenous injection.
When using butorphanol as a pre-anaesthetic, the use of an anticholinergic such as atropine, will protect the heart against possible narcotic-induced bradycardia.
Transient ataxia, anorexia and diarrhoea have been reported as occurring rarely.
Reduction in gastrointestinal motility may occur.
Cat:
Respiratory depression may occur. If respiratory depression occurs, naloxone may be used as an antidote.
Mydriasis is likely to occur.
Butorphanol administration may cause excitation, anxiety, disorientation and dysphoria.
Horse:
The most common side effect is mild ataxia which may persist for 3-10 minutes.
An increase in motor activity and ataxia produced by butorphanol lasted 1–2 hours in some cases.
Restlessness, and shivering and sedation followed by restlessness have both been observed in some horses.
A bolus IV injection at the maximum label dose (0.1 mg/kg body weight) may result in excitatory locomotor effects (e.g. pacing) in clinically normal horses.
Mild to severe ataxia may be encountered in combination with detomidine, but horses are unlikely to collapse. Normal precautions should be observed to prevent injury(see Special precautions for use in animals).
Mild sedation may occur in approximately 15% of horses following administration of butorphanol as a sole agent.
Butorphanol may also have adverse effects on gastrointestinal tract motility in normal horses, although there is no decrease in gastrointestinal transit time. These effects are dose-related, and generally minor and transient.
Depression of the cardiopulmonary system may occur. When used in combination with alpha2-adrenoceptor agonists, cardiopulmonary system depression may be fatal in rare cases.
The frequency of adverse reactions is defined using the following convention:
- very common (more than 1 in 10 animals treated displaying adverse reaction(s))
- common (more than 1 but less than 10 animals in 100 animals treated)
- uncommon (more than 1 but less than 10 animals in 1,000 animals treated)
- rare (more than 1 but less than 10 animals in 10,000 animals treated)
- very rare (less than 1 animal in 10,000 animals treated, including isolated reports).
Use during pregnancy and lactation
The safety of this veterinary medicinal product has not been established in the target species during pregnancy and lactation. The use of butorphanol during pregnancy and lactation is not recommended. See also Contraindications.
Interactions
When butorphanol is used in combination with certain α2-adrenoceptor agonists (romifidine or detomidine in horses, medetomidine in dogs and cats) synergistic effects occur requiring a butorphanol dose reduction (see Amounts to be administered and administration route).
Butorphanol is antitussive and should not be used in combination with an expectorant as it may lead to an accumulation of mucous in the airways.
Butorphanol has antagonist properties at the opiate mu (μ) receptor which may remove the analgesic effect of pure opioid mu (μ) agonists (e.g. morphine/oxymorphine) in animals that have already received these agents.
The concomitant use of other central nervous depressants would be expected to potentiate the effects of butorphanol and such drugs should be used with caution. A reduced butorphanol dose should be used when administering these agents concurrently.
Amounts to be administered and administration route
Dog and cat: Intravenous, intramuscular and subcutaneous use.
Horse: Intravenous use
Animals should be weighed to establish an accurate body weight prior to calculation of the appropriate treatment dose.
Dog:
Dog:
For analgesia:
Route
Dose butorphanol
Dose product
IV,IM or SC
0.20-0.30 mg/kg body weight
0.02-0.03 ml/kg body weight
Comment
Table wide
IV injection should be slow.
Analgesic effects are seen within 15 minutes of injection.
Administer 15 minutes before terminating anaesthesia to provide analgesia in the recovery phase.
For continuous analgesia repeat dose as required.
For sedation in combination with medetomidine hydrochloride:
Route
Dose butorphanol
Dose product
Dose medetomidine hydrochloride
IM or IV
0.1 mg/kg body weight
0.01 ml/kg body weight
0.01*-0.025**mg/kg body weight
Comment
Allow 20 minutes for profound sedation to develop before commencing the procedure.
Where compatibility is accepted, products containing medetomidine and butorphanol may be combined and administered in the same syringe (see Incompatibilities).
*Depending on degree of sedation required: 0.01 mg/kg: For sedation and as a premedicant to barbiturate anaesthesia.
**Depending on degree of sedation required 0.025 mg/kg: For profound sedation and as a premedicant to ketamine anaesthesia.
Table wide
For use as a premedicant/pre-anaesthetic:
1. When the product is used as the sole agent:
Route
Dose butorphanol
Dose product
IV, IM or SC
0.1-0.20 mg/kg body weight
0.01-0.02 ml/kg body weight
Comment
Table wide
15 minutes prior to induction.
2. When the product is used together with 0.02 mg/kg acepromazine:
Route
Dose butorphanol
Dose product
IV or IM
0.10 mg/kg body weight*
0.01 ml/kg body weight*
Comment
Allow at least 20 minutes before the onset of action but the time between pre-medication and induction is flexible from 20-120 minutes.
Where compatibility is accepted, products containing butorphanol and acepromazine may be combined and administered in the same syringe (see Incompatibilities).
* The dose may be increased to 0.2 mg/kg (equivalent to 0.02 ml/kg) if the animal is already experiencing pain before the procedure commences or if a higher plane of analgesia is required during surgery.
Table wide
For anaesthesia in combination with medetomidine and ketamine:
Route
Dose butorphanol
Dose product
Dose medetomidine
Dose ketamine
IM
0.10 mg/kg body weight
0.01 ml/kg body weight
0.025mg/kg body weight
5.0mg/kg body weight*
Comment
Reversal with atipamezole is not recommended
Where compatibility is accepted, products containing medetomidine and butorphanol may be combined and administered in the same syringe (see Incompatibilities).
* Ketamine should be administered 15 minutes after the IM administration of the butorphanol/medetomidine combination.
Table wide
Cat:
Cat:
For pre-operative analgesia:
Route
Dose butorphanol
Dose product
IM or SC
0.4 mg/kg body weight
0.04 ml/kg body weight
Comment
Table wide
Administer 15-30 minutes prior to the administration of IV induction anaesthetic agents.
Administer 5 minutes before induction with IM induction anaesthetic agents such as combinations of IM acepromazine/ ketamine or xylazine/ketamine.
For post-operative analgesia:
Route
Dose butorphanol
Dose product
SC or IM
0.4 mg/kg body weight
0.04 ml /kg body weight
IV
0.1 mg/kg body weight
0.01 ml /kg body weight
Comment
Table wide
Administer 15 minutes before recovery.
For sedation in combination with medetomidine hydrochloride:
Route
Dose butorphanol
Dose product
Dose medetomidine hydrochloride
IM or SC
0.4 mg/kg body weight
0.04 ml/kg body weight
0.05 mg/kg body weight
Comment
Table wide
Local anaesthetic infiltration should be used for wound suturing.
Where compatibility is accepted, products containing medetomidine and butorphanol may be combined and administered in the same syringe (see Incompatibilities).
For anaesthesia in combination with medetomidine and ketamine:
Route
Dose butorphanol
Dose product
Dose medetomidine
Dose ketamine
IM
0.40 mg/kg body weight
0.04 ml/kg body weight
0.08 mg/kg body weight
5.0 mg/kg body weight*
IV
0.10 mg/kg body weight
0.01 ml/kg body weight
0.04 mg/kg body weight
1.25-2.50 mg/kg body weight (depending on depth of anaesthesia required)
Comment
Table wide
Where compatibility is accepted, products containing medetomidine, butorphanol and ketamine may be combined and administered in the same syringe (see Incompatibilities).
Horse:
Horse:
For analgesia:
Route
Dose butorphanol
Dose product
IV
0.10 mg/kg body weight
1 ml/100 kg body weight
Comment
Table wide
Analgesic effects are seen within 15 minutes of injection.
Dose may be repeated as required.
For sedation in combination with detomidine hydrochloride:
Route
Dose of detomidine hydrochloride
Dose butorphanol*
Dose product
IV
0.012 mg/kg body weight
0.025 mg/kg body weight
0.25 ml/100 kg body weight
Comment
Table wide
Detomidine should be administered up to 5 minutes before the butorphanol dose.
*Clinical experience has shown that a total dose rate of 5 mg detomidine hydrochloride and 10 mg butorphanol affords effective, safe sedation in horses above 200 kg body weight.

For sedation in combination with romifidine:
Route
Dose of romifidine
Dose butorphanol
Dose product
IV
0.04-0.12 mg/kg body weight
0.02 mg/kg body weight
0.2 ml/100 kg body weight
Comment
Table wide
Romifidine should be administered up to 5 minutes before the butorphanol dose.
Before this product is combined and administered in the same syringe as another veterinary medicinal product always refer to the section on Incompatibilities.
The maximum number of vial punctures when using needle sizes 21G and 23G should not exceed 100 and when using a 18G needle, the maximum should not exceed 40.
Overdose
The main sign of overdose is respiratory depression, which can be reversed with naloxone.
To reverse the sedative effect of butorphanol/alpha-2 adrenoceptor agonist combinations, atipamezole may be used. To reverse adverse cardiopulmonary effects of these combinations, higher atipamezole doses may be required. Atipamezole should not be used in dogs treated with a combination of butorphanol, medetomidine, and ketamine used intramuscularly to produce anaesthesia.
Other possible signs of overdose in the horse include restlessness/excitability, muscle tremor, ataxia, hypersalivation, decrease of gastrointestinal motility and seizure. In the cat, the main signs of overdose are incoordination, salivation, and mild convulsions.
Withdrawal periods
Meat and offal: zero days
Not authorised for use in mares producing milk for human consumption.