Matthew Perry had similar amounts of ketamine in his system as a patient under general anaesthetic when he died, his autopsy revealed.
The 54-year-old actor was found dead in his hot tub on October 28 and on Friday, his passing was ruled an accident and found to be caused by the "acute effects" of the drug, with contributing factors cited as drowning, coronary artery disease, and the effects of buprenorphine, a drug used to treat opioid addiction.
The medical examiner noted the former 'Friends' star had been receiving ketamine infusion therapy as a depression treatment but the last session was a week and a half before his death and the substance only stays in the system for three to four hours.
The toxicology report found 3,540 ng/ml of ketamine were found in his peripheral blood source and 3,271 ng/ml were in his central blood source, but in “monitored surgical-anaesthesiologic care,” general levels are within the 1,000 to 6,000 ng/ml ranges.
According to DailyMail.com, medical examiner Raffi Djabourian wrote: "At the high levels of ketamine found in his postmortem blood specimens, the main lethal effects would be from both cardiovascular overstimulation and respiratory depression.
"Drowning contributes due to the likelihood of submersion into the pool as he lapsed into unconsciousness; coronary artery disease contributes due to exacerbation of ketamine induced myocardial effects on the heart.
"Buphrenorphine effects are listed as contributory, even though not at toxic levels, due to the additive respiratory effects when present with high levels of ketamine."
The expert logged that the '17 Again' actor had a history of emphysema, diabetes, and drug use - but he was "reportedly clean for 19 months" and having been a "heavy tobacco user for many years", they found he was "currently not smoking" at the time of his death.
And the examiner noted Perry was suffering from "chronic hepatic congestion" in the liver, a precursor to cirrhosis, had nephrosclerosis of the kidneys - a hardening of the tissues, caused by long term drug use and long-standing high blood pressure issues, and chronic pancreatic fibrosis, as well as damage to the heart and lungs.