Buprenex for Cats – How Does It Work?

Buprenex is an opioid pain medication which is biosynthetically similar to morphine, reticuline, and oripavine. Its generic name is buprenorphine hydrochloride. 

It is classified as a narcotic under the Controlled Substance Act due to its chemical makeover being derived from thebaine, a minor constituent of opium.

Buprenex is usually administered either intravenously or intramuscularly. It’s a powerful drug that is normally used by humans during surgery or to treat intolerable pain when prescribed by a doctor.

cat stretching itself

This narcotic is 30 times more powerful than morphine and is not available over the counter.

What are Opioids?

Opioids are medications that are derived directly from the poppy plant. The term can refer to natural, synthetic, or semi-synthetic products, but all of which draw from the same source for its ingredients.

Buprenorphine, unlike other opiates such as heroin, morphine, or codeine, has fewer side effects and doesn’t produce as much of a high as the other drugs. For this reason, it is commonly used as a treatment for people with drug addictions as it provides almost the same state of euphoria but without the intense side effects. It’s also much more difficult to overdose on Buprenorphine.

Today, you’ll learn about how Buprenex works for cats and other useful information such as the recommended dosage and potential side effects.

How It Works

Buprenex for cats is a totally different story compared to its usage on humans. The drug is usually prescribed to our pets for a couple of different reasons; the primary one being post-operative pain relief.

Most pet owners that have received a prescription from their veterinarian for Buprenex want to know if the drug is safe for their cats and if there are any negative side effects. The drug is quite reliable for use on cats – that being the actual reason why it is the go-to painkiller for animals compared to other opiates like morphine.

Luckily for us, our feline pets don’t have the opportunity to become addicted to Buprenex or similar opiates. The reason being, that this drug isn’t easily attainable. You can only purchase it if you have a prescription and the circumstance surrounding the need to use it is only for specific situations.

That being said, let’s walk through the process of how Buprenex is actually administered to cats.

It starts off with a recommendation from a veterinarian pre-operative, during, or post-operative. Some cats need serious medication for pain relief and the vet will suggest to use it if deemed necessary.

The drug works by blocking receptors in the brain which reduces the perceived feeling of pain that the cat would normally have. Pain is the brain’s way of sending a red-alert that the body has suffered some structural damage.

This is useful in everyday life, but when recovering from a surgery or during the surgery itself, pain can cause distress in the body which has a negative impact on the operation or healing process.

Post-operative Buprenorphine is usually delivered via intramuscular injections, sublingually or transdermal patches. Intravenous deliveries of the drug are reserved for the operating table.

cat yawning


The instructions regarding the correct dosage amount will be provided to you by the veterinarian along with the prescription. If left in your care to deliver to the cat at specified intervals, intramuscular (IM) injections may have been advised.

Carefully follow the instructions left with you, or if you’re not comfortable with doing the injection, ask your vet if you can get tablets instead. IM injections are typically administered at 0.005 to 0.01 mg per pound, two to four times a day.

Sublingual deliveries will usually be provided as a syringe with the Buprenex liquid already inside it. The liquid must be given orally to the cat twice a day. The Buprenex drug inside the syringe should be squirted either under the cat’s tongue or in the space between the cheek and the jawbone. As always, procure and follow the instructions provided by your vet.

Buprenorphine has powerful effects but it’s pretty difficult to overdose on it so you can rest easy knowing that the drug will work to its full potential. Just be sure not to exceed the dosage which was recommended by the vet.

Potential Side Effects

Buprenex is widely used as a painkiller for pets specifically because of the relatively few side effects that it causes. As with any medication, however, there will sometimes be unwanted reactions. The drug should not be used on cats that have certain types of health issues. Here are several:

  • Cats that have allergies or are hypersensitive to painkillers
  • Cats that have kidney disease, an underactive thyroid gland, or Addison’s disease
  • Cats that have had head trauma
  • Geriatric cats
  • Severely debilitated cats
  • Cats with a compromised cardiovascular function
  • Cats that have liver disease

Additionally, cats that are currently using other medications should not take Buprenorphine. If you’re unsure, contact your vet to find out if the drugs are safe to take simultaneously with others.

A few examples of such medications which can be potentially harmful if taken alongside Buprenex are antihistamines, barbiturates, tranquilizers, and monoamine oxidase inhibitors (anti-depressants).

Opioids are very powerful drugs and are not recommended for use on kittens, senior cats, and cats that are pregnant or nursing. In some rare cases, Buprenorphine can slow breathing as is seen when taking other opiates.

Sedation is a common side effect of Buprenex so don’t be too worried if your cat falls asleep under the influence of the drug. Other side effects may include a drop in blood pressure, higher heart rate, anorexia, and changes in body temperature (either high or low).

Although the circumstances are rare, if a veterinarian prescribes an incorrect dosage for your cat, there are a wide variety of side effects that could potentially occur. The more externally visible symptoms will be stomach problems or indigestion, sedation, weakness, and shortness of breath.

Studies have shown that if prescribed too much of the drug, it can repress the respiratory system and cause coma, unconsciousness, or death in the worst case.


You should now be well-informed on the common usages of opioids like Buprenex in cats. Be aware that since the drug is a narcotic, it has the potential to be abused by humans.

If you know of or suspect someone of using and abusing controlled substances such as Buprenex, please contact the Drug Enforcement Administration (DEA) using its number in your local directory.

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