Butorphanol

Butorphanol: Uses, Dosage and Side Effects

Overview

• It provides analgesia resulting from an affinity for the kappa opioid receptor.
• It has mu receptor antagonist properties.
• It has antitussive action resulting from central depression of the cough mechanism.

Uses of Butorphanol

• Management of mild perioperative pain.
• Provision of sedation through combination with acepromazine or alpha-2 agonists.
• Potent antitussive agent indicated for the relief of acute or chronic non-productive cough associated with tracheobronchitis, tracheitis, tonsillitis or laryngitis resulting from inflammatory conditions of the upper respiratory tract.

Dose of Butorphanol in Dogs and Cats

Dogs:

• Analgesia: 0.2–0.5 mg/kg i.v., i.m., s.c.
• Antitussive: 0.05–0.1 mg/kg i.v., i.m., s.c., 0.5–1 mg/kg p.o. q6–12h.

Cats:

• Analgesia: 0.2–0.5 mg/kg i.v., i.m., s.c.

Side Effects of Butorphanol in Dogs and Cats

• As a kappa agonist/mu antagonist, side effects such as respiratory depression, bradycardia and vomiting are rare after clinical doses.
• Cough suppression following torbugesic tablets may be associated with mild sedation.

Contraindications of Butorphanol in Dogs and Cats

• Animals with diseases of the lower respiratory tract associated with copious mucus production.
• Premedication when the administration of potent opioids during surgery is anticipated.

Some Notes:

• Butorphanol has a very rapid and relatively short duration of action (lasting between 45 minutes and 4 hours ).
• Butorphanol is metabolized in the liver and some prolongation of effect may be seen with impaired liver function.
• Butorphanol crosses the placenta and may exert sedative effects in neonates born to bitches and queens treated prior to parturition.
• Butorphanol is unlikely to be adequate for the management of severe pain.
• Higher doses of full mu agonists may be needed to provide additional analgesia after butorphanol but it is not necessary to wait 4 hours after butorphanol administration to give other opioids.
• Response to all opioids appears to vary between individuals; therefore, assessing pain after administration is imperative.
• In familiar with other opioids, butorphanol will reduce the doses of other drugs required for induction and maintenance of anesthesia.
• Combination with full mu agonists is not recommended for analgesia, the addition of butorphanol will reduce analgesia produced from the full mu agonist.