What to know about ketamine therapy after Matthew Perry's cause of death announced

An autopsy report from the Los Angeles County coroner on Friday named acute effects of ketamine as the cause of death for "Friends" star Matthew Perry.

According to the report, Perry reportedly was on ketamine infusion therapy and had a ketamine infusion one-and-a-half weeks prior to his death. However, the medical examiner concluded that the ketamine in his system could not have been from that infusion, as ketamine has a half-life of three to four hours or less.

The report also listed drowning, coronary artery disease and buprenorphine effects as contributing factors not related to the immediate cause of death, Perry's death was ruled an accident.

Buprenorphine is a medication used to treat Opioid Use Disorder (OUD), according to the Substance Abuse and Mental Health Services Administration.

Here is a look at what ketamine is and how it is used in medical treatment.

What is ketamine?

Ketamine is a dissociative anesthetic used medically to induce anesthesia. In more recent years, it's also been used as a treatment for treatment-resistant depression, according to StatPearls, an online library published in the National Library of Medicine.

According to American Addiction Centers, Ketamine has a "potential for recreational misuse."

What is ketamine therapy?

According to the Drug Enforcement Agency (DEA), ketamine was approved in the 1970s as a rapid-acting anesthetic by the U.S. Food and Drug Administration (FDA).

In recent years, off-label ketamine has been used to treat psychological disorders like depression and PTSD.

"The average antidepressant takes about two months to produce a reduction in symptoms," Dr. John Crystal, co-director of the Yale Center for Clinical Investigation, told ABC News' Eva Pilgrimin November. "Ketamine produces those same kinds of improvements within 24 hours in many people."

Ketamine therapy made headlines in 2021 when former NBA player Lamar Odom opened up to "Good Morning America" about his use of the drug therapy to help him battle addiction. "I went to rehab and did some other things, but ketamine came into my life at the right time," Odom told ABC News' Steve Osunsami.

"I think of ketamine as an intervention that is part of an overall treatment," said Crystal. "Ketamine can be something that can facilitate and enhance the impact of psychotherapy."

Potential risks of ketamine therapy

"Death by ketamine overdose rarely occurs if ketamine is the only drug someone takes," according to American Addiction Centers.

The lethal dose of ketamine is estimated to be about 5.6 milligrams per pound for a 154-pound human, according to the StatPearls journal in the National Library of Medicine.

Beyond the risk of death, Dr. John Crystal, co-director of the Yale Center for Clinical Investigation, told Eva Pilgrim in November that ketamine therapy should not be used by people with schizophrenia or people who are developing a psychiatric illness.