Urinary phencyclidine excretion in chronic abusers.

Data on usage patterns of 100 hospitalized chronic phencyclidine abusers was collected. Weekly urine samples were monitored using a new gas chromatographic nitrogen detector analysis for PCP. Abusers were found to be, on the average, young males who had used PCP for approximately 40 months (range 12 to 96 months) and approximately 3 to 4 d/week. Except for one subject, urines became negative for PCP within 30 d after last use with a mean of 14 d. There was rapid excretion during the first 9 d followed by a more gradual reduction in urine PCP levels.