One of two California doctors who were among the five people charged in the overdose death of Friends star Matthew Perry has pleaded guilty to illegally distributing the drug ketamine.

Mark Chavez of San Diego entered the plea during an appearance in US District Court in Los Angeles on Wednesday. He could face up to 10 years in prison at his sentencing, which was scheduled for April.

Another physician charged in the case, Salvador Plasencia, has pleaded not guilty, as has co-defendant Jasveen Sangha, who authorities said was an illicit supplier of the drug and was known as the “ketamine queen”. The pair are scheduled to go on trial in March.

Perry’s live-in personal assistant, Kenneth Iwamasa, who admitted to injecting Perry with the drug, and the alleged middleman who said he obtained ketamine from Sangha, have already pleaded guilty to charges they faced.

Authorities said Plasencia purchased ketamine from Chavez, and in text messages to Chavez discussing the amount to charge Perry for the drug wrote: “I wonder how much this moron will pay.”

In court on Wednesday, Chavez, 54, stood at a podium and answered “yes, your honour” to a series of questions.

The defendant admitted to obtaining ketamine with a fraudulent prescription written for another patient and that he knew the drug was intended for Perry.

He also acknowledged providing ketamine, a short-acting anaesthetic, to Plasencia, and that he understood it should only be administered under medical supervision with proper safety equipment nearby.

According to court documents, Plasencia administered ketamine to Perry at the actor’s home and supplied vials that were injected by the assistant. Plasencia’s lawyer has said his client properly prescribed and administered ketamine to Perry.

From the left, David Schwimmer, Lisa Kudrow, Matthew Perry, Courteney Cox, Jennifer Aniston and Matt LeBlanc pose after Friends won outstanding comedy series at the 54th Primetime Emmy Awards in 2002 [Reed Saxon/AP Photo]

Perry died aged 54 in October 2023 from “acute effects” of ketamine and other factors that caused him to lose consciousness and drown in his hot tub, according to a December 2023 autopsy report.

The actor had publicly acknowledged decades of substance abuse, including during the years he starred as Chandler Bing on the hit television sitcom Friends.

He starred alongside Jennifer Aniston, Courteney Cox, Lisa Kudrow, Matt LeBlanc and David Schwimmer for 10 seasons from 1994 to 2004.

The actor had been using ketamine through his regular doctor in a legal but off-label treatment for depression that has become increasingly common.

Perry began seeking more ketamine than his doctor would give him. About a month before the actor’s death, he found Plasencia, who in turn allegedly asked Chavez to obtain the drug for him.

Chavez pleaded guilty under an agreement with prosecutors, who offered him lesser charges for his assistance in their case against Plasencia and Sangha.

“He has accepted responsibility. He is cooperating,” Matt Binninger, Chavez’s lawyer, said in court.

Chavez has relinquished his medical licence and remains free on bond until his sentencing.