According to Matthew Perry's assistant Kenneth Iwamasa, the actor's dissociative drug ketamine use in the weeks preceding his October 2023 death was apparently rather high. A plea bargain with the Department of Justice claims that Iwamasa obtained over $55,000 worth of ketamine from many vendors, then given it to Perry.

Five people-including Iwamasa, who injected Perry with ketamine despite lacking medical knowledge-have been arrested by authorities in relation to Perry's death. Iwamasa acknowledged several injections, including ones on the day Perry passed away.

Iwamasa participated in group projects as well, including working with Dr. Salvador Plasencia to learn drug distribution techniques. Plasencia got the ketamine from Dr. Mark Chavez, supposedly hiding the drug's transfer under false prescriptions. Chavez has also agreed to enter a guilty plea on conspiracy allegations.

Originally reported as an apparent drowning, Perry's death on October 28, 2023, was later proven by an autopsy to be "acute effects of ketamine," together with contributory factors including coronary artery disease. Iwamasa has admitted guilt to conspiracy to distribute ketamine causing death; the inquiry is still under progress as further specifics of the sad incident surface.