Is ketamine an opioid? No – and how it works may surprise you.
Pain. Our least favorite thing.
However, pain plays a vital role in our survival. It tells us when we’ve suffered an injury somewhere in the body, and it’s a warning to avoid certain situations or behaviors in the future. For example, pain is our body's way of telling us, "if you put your hand on a hot stove, it will hurt."
Researchers have long tried to find ways to treat this defense mechanism so that surgeries can be performed, recovery after an injury or illness can be comfortable, and those with debilitating chronic pain can participate in the things they enjoy. This has led to the development of a variety of different drug classes. In recent news, you may have heard of medications like opioids or ketamine. We explain the differences between the two.
Is ketamine an opioid?
Ketamine is not an opioid. Ketamine works by suppressing glutamate signaling in your brain, while opioids ”hijack” your endogenous (naturally occurring) opioid system.
Dr. Shannon Eaton, a neuroscientist and Assistant Teaching Professor of Psychology at Arizona State University says, “Heroin, fentanyl and morphine are all in the opioid class. These opioids tend to activate a specific system called our opioid system, or our endogenous opioid system.”
She explains, “So we have a naturally occurring pain relief system, and it's kind of what people think of when you run a lot and you get ‘endorphin release.’ It makes you feel good. It's also really helpful to kind of suppress pain signals. We don’t want pain signals if we are actively trying to escape a painful situation, like if a bear is attacking us. This goes back to evolutionary reasons. We have to have a way to get away, even if there's pain in our body – we have to have some overriding system for that pain to survive the immediate threat.”
Eaton further explains that opioid medications work on the same naturally occurring system, leading to pain relief and also feelings of pleasure – which is what can sometimes lead to addiction.
Ketamine works differently. It is known as a dissociative anesthetic or dissociative hallucinogen. The effects are dose-dependent, but it generally leads to a “disconnected” feeling from you, your person – and your body. Symptoms range from unconsciousness, (like when used in general anesthesia) to an “out of body” experience or hallucinations.
How does it work? Eaton says that ketamine binds to NDMA receptors, which aids in the transmission of the excitatory neurotransmitter glutamate – our brains’ “go” signal. Ketamine stops these signals, which, in turn, can stop feelings of pain.
What is ketamine used for?
Dr. Ryan Marino, a Medical Toxicologist, Emergency Medicine Physician and Associate Professor at Case Western Reserve School of Medicine in Cleveland, Ohio, explains that ketamine is considered a general anesthetic, but can be used for many different medical purposes. “Ketamine was primarily developed for anesthesia for surgical procedures, and it is still used for that indication today. It is also used as a general sedative – so for people who are on ventilators or if they have some other kind of critical illness and need continuous medication for comfort and sedation.”
He adds that it’s also used in the emergency department for some minor procedures like reducing fractures and dislocations. It can also be used to sedate agitated people who are at risk of harming themselves or others.
Ketamine has recently received attention because of the role it played in Matthew Perry’s death. Perry was using ketamine under the care of a physician for the treatment of depression, although the levels of ketamine in his system at the time of his death weren’t related to his last infusion. When taken properly, ketamine can be a safe and effective treatment for depression and pain, although the nasal spray, Spravato, is the only medication approved by the FDA.
Is ketamine addictive?
Marino says generally, the risk of addiction is low since people don’t get the same kind of tolerance as with some drugs associated with long-term dependence like opioids, however, the risk is not zero.
Ketamine is a tool in a medical professional's belt for the treatment of pain. Like all medications, there are benefits and risks associated with it. The best practice is to be as informed and prepared as possible so you can make the best decisions for your health and well-being.
More: Pain is by far the most common chronic ailment in America, study finds
This article originally appeared on USA TODAY: Is ketamine an opioid? Facts of drug involved in Matthew Perry's death
