Patients using PCP display very specific symptoms including what type of nystagmus?

Patients using phencyclidine (PCP) typically display vertical nystagmus as one of their hallmark symptoms. Vertical nystagmus refers to involuntary eye movements that occur in a vertical direction, which is a distinguishing feature in individuals under the influence of PCP. This is particularly important in clinical settings for identifying PCP use, as other substances may cause different types of nystagmus or not cause nystagmus at all.

The presence of vertical nystagmus can aid healthcare providers not only in recognizing PCP intoxication but also in differentiating it from other hallucinogens and substances. Understanding this symptom is crucial for appropriate intervention and management of patients experiencing PCP effects.