Ketamine and Phencyclidine (PCP) By Gerald F O'Malley, DO, Grand Strand Regional Medical Center; Rika O'Malley, MD, Grand Strand Medical Center Reviewed / Revised Dec 2022 View Patient Education Symptoms and Signs Diagnosis Treatment More Information Ketamine and phencyclidine are N-methyl-D-aspartate receptor antagonists and dissociative anesthetics that can cause intoxication, sometimes with confusion or a catatonic state.