What is ketamine, the drug involved in Matthew Perry's death?

The investigation into the death of “Friends” star Matthew Perry has resulted in a sweeping indictment, including five people who prosecutors say contributed to his ketamine overdose in October. Among them were two doctors and a street dealer who supplied Perry with large quantities of the powerful anesthetic.

Here's what you should know about ketamine.

Ketamine is a powerful anesthetic approved by the U.S. Food and Drug Administration for use during surgery. It can be administered as an intramuscular injection or intravenously.

The drug is chemically related to the recreational drug PCP. Ketamine itself is used recreationally because of its euphoric effects. It can cause hallucinations and affect breathing and the heart.

Ketamine has seen a huge increase in use in recent years as a treatment for depression, anxiety and pain. Although the drug is not approved for these conditions, doctors can prescribe it for what are known as off-label uses.

In Perry's case, he was taking it to treat depression. He was given ketamine infusion therapy by his doctors, but prosecutors said the actor turned to other sources when his doctors would not give him more doses.

Prosecutors said Thursday that Perry obtained ketamine illegally through a network that included two doctors, his assistant and a woman they called the “ketamine queen.” Perry's assistant, who pleaded guilty to one count of conspiracy to distribute ketamine resulting in death, injected the actor with ketamine – including several times on the day of his death.

“We are not talking about legitimate ketamine treatment here,” said U.S. Attorney Martin Estrada when announcing the charges. “We are talking about two doctors who abused the trust they had and abused their license to endanger the life of another human being.”

Ketamine has also been used by paramedics as a sedative, often while working with police when they believed victims were out of control. Some states and authorities have begun to reconsider this practice due to its dangers. The 2019 death of a young black man named Elijah McClain in Colorado drew attention to the practice and led to two paramedics being convicted of administering a ketamine overdose to McClain.

Overall, the practice of administering ketamine and other tranquilizers in police custody has spread quietly across the country over the past 15 years. It is based on questionable science and supported by experts close to the police, an Associated Press investigation found.

___

The Associated Press Health and Science Department receives support from the Science and Educational Media Group of the Howard Hughes Medical Institute. All content is the responsibility of the AP.