Cats are like any of our close friends or family members when it comes to health; we never want to see them get hurt, suffer debilitating illnesses, or require major surgeries, but these things can and do happen. There are, of course, tons of pain killers for humans in these sad eventualities, but what pain relief options are available if you have a cat in pain? One powerful short-term analgesic has been the focus of increased use and study in cats: buprenorphine.

There’s plenty to unpack here, first in terminology, then in proper use, and finally in potential side effects when it comes to cats. After all, in humans, buprenorphine is an opioid that is commonly used to wean people off addictions to other opioids, such as heroin. Fortunately, there are not a lot of cats who are smack addicts, and the dosages for cats are far smaller and prescribed with great care by certified veterinarians.

What is an analgesic? What is an opioid?

Let’s quickly and briefly define some of our terms. When it comes to caring for cats, we should be well aware of what exactly we are giving them in service of pain relief. “Analgesic” is the simplest place to start. Not to go too far down the etymological trail, but the word derives from Greek, and it means a method of freeing someone from pain. This includes medications ranging in strength from children’s aspirin and mundane, over-the-counter things such as ibuprofen to dangerously -addictive drugs such as morphine and buprenorphine.

These last two are classified as opiates, or, more broadly, opioids. What are opiates, then? And how are they different from opioids? Strictly speaking, a proper opiate is a medication whose direct source is found in the poppy plant. An opioid used to be medications synthetically crafted to mimic or duplicate the actions of naturally derived opiates. Today, “opioid” is the preferred nomenclature, because it encompasses natural, semi-synthetic, and purely synthetic products. Opioids do not treat the source of pain or distress, they simply block receptors in the brain that send pain messages to the body.

What, then, is buprenorphine?

Cats generally have a poor tolerance for opioids. One major reason is the drugs’ power and effects on our small feline friends. Aside from masking pain, opioids also affect and slow down respiration. However, buprenorphine, often administered under the name Buprenex, was found to be a welcome exception. Buprenorphine is a semi-synthetic opioid, which is neither as strong, as long-lasting, nor as potentially addictive as other human opioids such as hydrocodone or morphine. This pain medication does not affect or depress breathing as much either.

Buprenorphine is prescribed by certified veterinarians in small and measured doses determined cat by cat based on weight, age, and overall health factors. These include liver and kidney function. As opioids work their way through a cat’s body, they are filtered and eventually pass through the system by the liver and kidneys. A cat who has major issues with these filtration organs, or one with thyroid problems, may not be a candidate for buprenorphine use. Lung health is also a factor; even though this opioid doesn’t affect breathing as much, it can be dangerous for cats with respiratory problems.

What is buprenorphine used for in cats?

A cat who has suffered a severe trauma or dramatic physical injuries is a potential subject for buprenorphine treatment. The drug is used to relieve pain and increase feelings of euphoria in cats after major surgeries following incidents of these kinds. It is also finding increased use in adult cats taken in for spaying and neutering surgeries as a pre- and post-operative means of pain control in the first place and relief in the second. I say “increased” use, but this does not mean it is commonplace.

Buprenorphine is a very powerful medication. Certified veterinarians use it in situations where a cat is believed to be in extreme pain, anxiety, and distress, either because of injury or in response to surgery, and is not responding as hoped to more common alternatives. Anyone who’s had a painful surgery knows, post-operative stress and anxiety can be just as deleterious to health and recovery as the physical pain itself. So it is with cats, and buprenorphine helps to mask their pain in an effort to avoid decreased appetite, negative changes in behavior, and other consequences of physical pain.

While it is becoming more widely used for pain relief in cats, buprenorphine still carries risks for cats. Their smaller bodies can react in a variety of ways to this opioid, so typically it is administered by the veterinarians themselves so that the reactions can be closely and carefully monitored. It is given either as a direct injection at the site of the surgery or trauma, or rubbed into the gums. Both methods seem equally effective and allow the pain killer to work before the liver and kidneys filter and pass it out of the system. A standard dosage takes about half an hour to 45 minutes to start working, and its effects on a cat can last from four to eight hours.

Side effects of opioid pain killers in cats

Because the medication does not last very long in a cat’s system, buprenorphine is usually given two to three times a day for as long as five days. The reason for this isn’t necessarily because of its addictive qualities, but rather because at this point, it can have negative impact on a cat’s appetite and weight. There is no real standard yet for buprenorphine in cats because cats have such a variety of reactions to it. Side effects, as they say, are generally mild, but can include the aforementioned appetite loss and slowed respiration. Some cats can have allergic reactions to it, and it should never be taken in combination with other medications, including certain flea and tick preventatives.

Cats need pain relief, too

One of the most bizarre facts I found in researching buprenorphine use in cats — especially side effects — is that not only does it interact badly with other medications, but also with certain kinds of aged cheese. I couldn’t make that up if I tried, so make sure you keep your cheese plates and other hors d’oeuvres well out of the reach of your cat if she is recovering from a major surgery.

At the risk of sounding like one of those interminable and omnipresent commercials on television, buprenorphine is not recommended for use on kittens, senior cats, or those who are either pregnant or nursing. Opioids are too powerful and unpredictable for very young or old cats, and too risky for unborn or newborn cats and their mothers. A 2014 study of buprenorphine use in cats was largely inconclusive. Researchers found it to be generally safe in proper doses and with careful veterinary monitoring, but they stated that its effects and utility, as a pain reliever and a sedative for cats, can be inconsistent.

About the author: Melvin Peña trained as a scholar and teacher of 18th-century British literature before turning his research and writing skills to puppies and kittens. He enjoys making art, hiking, and concert-going, as well as dazzling crowds with operatic karaoke performances. He has a one-year-old female Bluetick Coonhound mix named Idris, and his online life is conveniently encapsulated here.