(WGHP) — On Friday, the Los Angeles County Medical Examiner announced that actor Matthew Perry died from the acute effects of the anesthetic ketamine.

Perry’s unexpected death brought ketamine to the forefront of discussion. Which brings up the question, what is ketamine?

Ketamine is a dissociative anesthetic that has some hallucinogenic effects, according to the U.S. Drug Enforcement Administration.

The DEA says that ketamine can distort a person’s eyesight and hearing. It also can make a person feel disconnected and not in control and is thus called a “dissociative anesthetic hallucinogen.”

Ketamine can make a person “feel detached from their pain and environment,” according to the DEA. Ketamine induces a sense of sedation, relief from pain, immobility and amnesia.

The DEA says that ketamine is abused due to its “dissociative sensations and hallucinogenic effects.”

Ketamine is an approved medical product as a short-acting use anesthetic for humans and animals, according to the DEA. It is also used as a nasal spray for treatment-resistant depression. Ketamine is also used to facilitate sexual assaults.

The DEA says that the overdosing effects of ketamine are dangerously slowed breathing and unconsciousness.

Side effects of ketamine use include agitation, depression, cognitive difficulties, unconsciousness, and amnesia, according to the DEA. Involuntarily rapid eye movement, dilated pupils, salivation, tear secretions, stiffening of the muscles and possible nausea.

Hallucinogen Persisting Perception Disorder (HPPD) has been reported several weeks after ketamine use and may include experiencing prolonged visual disturbances.