Matthew Perry dies of effects of ketamine: How often does the drug lead to death?

Matthew Perry’s cause of death has been confirmed, weeks after he unexpectedly died.

The "Friends" star died of acute effects of ketamine, according to the Los Angeles County Medical Examiner’s Office.

Matthew Perry's cause of death

The 54-year-old actor's cause of death was described as "acute effects of ketamine." How and why he took the ketamine was unclear.

"Contributing factors in Mr. Perry’s death include drowning, coronary artery disease and the effects of buprenorphine (used to treat opioid use disorder). The manner of death is accident," the Los Angeles County Medical Examiner's Office said in a statement.

The autopsy report, obtained by NBC News, further explained that the ketamine likely led Perry to become unconscious and drown, and existing coronary artery disease exacerbated the ketamine's effects on his heart.

What is ketamine?

Ketamine is a "dissociative anesthetic that has some hallucinogenic effects," according to the U.S. Drug Enforcement Agency. It's been approved by the U.S. Food and Drug Administration as an injectable, short-acting anesthetic for humans an animals.

Ketamine can also be used as a therapy for mental illnesses, like depression and anxiety. It’s also used recreationally "due to its 'dissociative' nature, indicating disconnection from mind and body," according to the autopsy report.

The effects it has on a person include feeling disconnected from their environment and any pain. It can also create a feeling of sedation and immobility.

How can ketamine lead to death?

When a person overdoses on ketamine, they may go unconscious and their breathing may slow to a dangerous degree, according to the DEA.

The autopsy report explained that "at the high levels of ketamine found in (Perry's) postmortem blood specimens, the main lethal effects would be from both cardiovascular over stimulation and respiratory depression."

"It's easy to take too much (ketamine), more than you're supposed to," NBC News senior medical correspondent Dr. John Torres said on TODAY Dec. 18. "If you do, you're going to have racing heartbeat, you're going to have your blood pressure going up, you're going to have this dissociation from your body that people describe as uncomfortable."

"If you take too much — anesthetic-type levels — you can get to the point where your respiration's depressed, you're (drowsy) and can't respond ... and unfortunately, if you go under water, you might not be able to respond to that," he continued.

That said, “it’s rare to die from ketamine overdose,” he added.

What is ketamine therapy?

Ketamine therapy is when the drug is used, usually by infusion, injection or inhaling, to treat mental illnesses like depression or anxiety, TODAY previously reported. Torres added that some research shows it may work for posttraumatic stress disorder and addiction, as well.

Perry had written in his memoir about using ketamine therapy to help with mental illness. His last known treatment before his death was a week and a half prior, according to the autopsy report.

Growing research shows ketamine can be a powerful tool to treat depression that hasn't improved with other medication or therapy. It's unclear exactly how ketamine may improve depression and anxiety symptoms, but it likely works by boosting feel-good chemicals, similar to traditional antidepressants, and helping form new pathways in the brain to encourage new thought patterns and behaviors, Mike Dow, Ph.D., a psychotherapist at ketamine clinic Field Trip, in Los Angles previously told TODAY.

How did Matthew Perry die?

Perry's cause of death was due to "acute effects of ketamine." Ketamine is approved by the FDA as an anesthetic, but it can also be used recreationally and as a therapy for depression and anxiety.

Drowning and coronary artery disease were also contributing factors in Perry's death, per the medical examiner.

Perry was found unresponsive in a jacuzzi at his Pacific Palisades, California, home on Oct. 28. He was pronounced dead of an apparent drowning, according to authorities.

The official cause of death had been pending a toxicology report and further investigation, per a report released on Oct. 29 by the medical examiner’s office. Additionally, on his death certificate, the cause of death was listed as deferred.

As news of his death was announced, two law enforcement sources had told NBC News that there were no obvious signs of trauma or foul play.

Did Matthew Perry relapse?

The autopsy report did not specify if Perry relapsed before his death. It did state that he had been "reportedly clean for 19 months" before he died.

Perry had been doing ketamine therapy and had his last known session a week and a half before he died. The autopsy report noted that, per the medical examiner, the amount of ketamine found in his system could not have been from the therapy a week and a half earlier, as the drug has a half-life of three to four hours at most.

Matthew Perry's earlier health problems

Perry had been open about his health problems due to drugs and alcohol and his hope of helping others struggling with addiction. He estimated to the New York Times that he spent $9 million trying to get sober, detailing this journey in his memoir, “Friends, Lovers and the Big Terrible Thing.”

“I lived half my life in one form or another of treatment center or sober living house. Which is fine when you are twenty-four years old, less fine when you're forty-two years old," the book's prologue reads. "Now I was forty-nine, still struggling to get this monkey off my back.”

He also told radio host Tom Power in a November 2022 interview that he didn’t like to watch "Friends" episodes because he could tell when he was struggling with his addictions.

Perry also faced several health issues, including a near-death experience in 2019. After his colon erupted, he went into a two-week-long coma and was subsequently hospitalized for five months.

Despite his struggles, Perry wanted to help others with their sobriety journey.

“When I die, I don’t want ‘Friends’ to be the first thing that’s mentioned. I want that to be the first thing that’s mentioned,” he told Power of helping people get sober. “And I’m going to live the rest of my life proving that.”

Almost a week after his death, on Nov. 3, the Matthew Perry Foundation was announced to help people struggling with addiction.

The “17 Again” leading man was buried in an intimate funeral on Nov. 3 at Forest Lawn Memorial Park in Los Angeles, according to People.

His “Friends” co-stars Jennifer Aniston, Courteney Cox, Lisa Kudrow, Matt LeBlanc and David Schwimmer were in attendance, per the magazine.

This article was originally published on TODAY.com