Matthew Perry had tried for years to stay sober ... Perry's longtime assistant, Kenneth Iwamasa, administered another dose roughly four hours later while the actor watched a movie.

Perry, who had been taking the drug six to eight times a day before he died, "believed deeply in eliminating the stigma" around addiction, the foundation said.

Fallen 'Friends' Actor and Assistant Splashed $55,000 on Killer Ketamine in Last Weeks of His Life Matthew Perry and his assistant Kenny Iwamasa spent at least $55,000 for 55 vials of ketamine in ...