include Butorphic, Dolorex, Morphasol, Torbugesic, and Torbutrol. Legality Butorphanol is listed under the Single Convention on Narcotic Drugs 1961 and in the United States is a Schedule IV Narcotic controlled substance with a DEA ACSCN of 9720; being in Schedule IV it is not subject to annual aggregate manufacturing quotas. The free base conversion ratio of the hydrochloride is 0.69. Butorphanol was originally in Schedule II and at one point it was decontrolled. Veterinary use In veterinary anesthesia, butorphanol (trade name: Torbugesic) is widely used as a sedative and analgesic in dogs, cats and horses. For sedation, it may be combined with tranquilizers such as alpha-2 agonists (medetomidine), benzodiazepines, or acepromazine in dogs, cats and exotic animals. It is frequently combined with xylazine or detomidine in horses. Butorphanol is used for sedation and mild to moderate pain control in dogs and cats. It is not considered adequate pain control in dogs undergoing surgical pain. It is used for operative and accident-related pain in small mammals such as dogs, cats, ferrets, coatis, raccoons, mongooses, various marsupials, some rodents and perhaps some larger birds. Although butorphanol is commonly used for pain relief in reptiles, no studies (as of 2014) have conclusively shown that it is an effective analgesic in reptiles. Use in horses Butorphanol is a commonly used narcotic for pain relief in horses. It is administered either IM or IV, with its analgesic properties beginning to take effect about 15 minutes after injection and lasting 4 hours. It is also commonly paired with sedatives, such as xylazine and detomidine, to make the horse easier to handle during veterinary procedures. Side effects specific to horses include sedation, CNS excitement (displayed by head pressing or tossing). Overdosing may result in seizures, falling, salivation, constipation, and muscle twitching. If an overdose occurs, a narcotic antagonist, such as naloxone, may be given. Caution should be used if butorphanol is administered in addition to other narcotics, sedatives, depressants, or antihistamines as it will cause an additive effect. Butorphanol can cross the placenta, and it will be present in the milk of lactating mares who are given the drug. The drug is also prohibited for use in competition by most equestrian organizations, including the FEI, which considers it a class A drug. See also Levallorphan Nalbuphine Nalfurafine Nalorphine Xorphanol Notes References Tertiary alcohols Analgesics Equine medications Kappa-opioid receptor agonists Morphinans Phenols Synthetic opioids Cyclobutyl compounds Cat medications