By Kayla Hyland, DVM; Rania Gollakner, BS, DVM, MPH

What is butorphanol?

Butorphanol (brand names: Stadol®, Torbutrol®, Torbugesic®, Dolorex®) is a systemic partial opiate agonist/antagonist used as an analgesic (pain control medication), pre-anesthetic, antitussive (cough suppressant), or antiemetic (prevents vomiting). It is a Schedule IV controlled substance under the U.S. Controlled Substances Act.

Its use in cats and dogs to treat certain conditions is “off label” or “extra label”. Many drugs are commonly prescribed for off-label use in veterinary medicine. In these instances, follow your veterinarian’s directions and cautions very carefully as their directions may be significantly different from those on the label.

How does butorphanol work?

Butorphanol works for a short duration to alleviate mild to moderate pain. It also acts as an antagonist to pure opioids (such as morphine), so it can be used to reverse the effects of opioids while still providing pain control. You should notice your pet feeling better about 1 to 2 hours after receiving the dose.

How is butorphanol given? 

Butorphanol is given by mouth in the form of an oral tablet or given by subcutaneous, intramuscular, or intravenous routes in the form of an injectable solution. The oral tablet can be given with or without food. Your veterinarian will give the injectable solution.

What if I miss giving my pet the medication or my shipment is late?

If you miss a dose, give it when you remember; however, if it is close to time for the next dose, skip the dose you missed, give it at the next scheduled time, and return to the regular dosing schedule. Never give your pet two doses at once or give extra doses.

Are there any potential side effects?

Butorphanol is a short-acting drug and will generally be out of your pet’s system within 24 hours, although the effects may last longer if your pet has decreased liver or kidney function. Side effects include sedation, excitement, respiratory depression, ataxia, anorexia, dilated pupils in cats, or rarely diarrhea. In very high doses, central nervous system (CNS) effects such as seizures, cardiovascular changes, and respiratory depression may occur.

Are there any risk factors for this medication?

Butorphanol should not be given to pets that are hypersensitive to it. It should be used with caution in patients with hypothyroidism, severe kidney impairment, Addison’s disease, liver disease, lower respiratory tract disease, heartworm disease, and in geriatric or severely debilitated patients.

It should be used with extreme caution in patients with head trauma or other CNS dysfunctions (such as coma or increased cerebrospinal fluid pressure). Be sure to tell your veterinarian about any conditions your pet may have.

Butorphanol should be used carefully in dogs with MDR1 (ABCB-1) mutations. Dog breeds most commonly found to have the MDR1 mutation include Australian shepherds, Shetland sheepdogs, collies, long-haired whippets, and silken windhounds. Your veterinarian will weigh the pros and cons of using this drug in these breeds and will decrease the dosage by 25-50% if it is used.

Use in pregnant or breeding animals is not recommended, as the safety of this drug in pregnant animals has not been established, but if required, it should be used with caution. Butorphanol should be used with caution in nursing mothers.

Are there any drug interactions I should be aware of?

The following drugs should be used in caution with butorphanol: anticholinergics, antidiarrheals, antihypertensives (e.g., benazepril, amlodipine, atenolol, etc), apomorphine, bromocriptine, cimetidine, CNS depressant agents, desmopressin, diuretics, erythromycin, fenoldopam, fentanyl, furazolidone, ifosfamide, iohexol, itraconazole, lithium, methylene blue, metoclopramide, MAOIs, pancuronium, phenoxybenzamine, polyethylene glycol, procarbazine, SSRIs, tamsulosin, theophylline, tramadol, tricyclic antidepressants, and vasodilators.

Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking.

Is there any monitoring that needs to be done with this medication?

Your pet’s respiratory rate should be monitored, especially at higher doses. Appetite, bowel function, urinary function, and central nervous system effects should be monitored closely, and any changes should be reported to your veterinarian. Your veterinarian may also monitor your pet to be sure that the medication is working.

How do I store butorphanol?

The tablets should be stored at room temperature, 20°C–25°C (68°F–77°F) and away from light. The injectable product should be stored out of bright light and at room temperature.

Butorphanol is a controlled substance, which means that it has been designated by the Drug Enforcement Administration (DEA) as having a potential for diversion to people other than the patient it was prescribed for. Use of a controlled substance in any person or animal other than that for which it is prescribed is illegal. Therefore, this medication should be stored in a locked cabinet or safe that cannot be easily moved, with access limited to only those that need to administer the medication. Monitor the amount of medication remaining to ensure the expected amount is present.

What should I do in case of emergency?

In cases of overdose, if life threatening clinical signs occur, take your pet to your veterinarian or veterinary emergency facility immediately. Your pet will need to be treated as quickly as possible.

If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility.

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