Phencyclidine Screen and Confirmation Urine

What this test measures

Phencyclidine, or PCP, is a dissociative drug that can be detected in urine after use. The screening immunoassay compares the sample signal to a cutoff set by the laboratory. If the signal is below the cutoff, the result is reported as negative. If it is at or above the cutoff, the result is presumptive positive and typically proceeds to confirmation.

Confirmation is usually performed by liquid chromatography with tandem mass spectrometry or gas chromatography with mass spectrometry. These methods identify phencyclidine itself and can report a concentration, which helps distinguish true positives from cross-reactive substances. Laboratories may also assess specimen validity using measurements such as creatinine, pH, and specific gravity.

This test is ordered in clinical or authorized testing contexts, and it should be requested through an appropriate provider or testing program. Detection windows depend on factors such as dose, frequency of use, hydration, and individual metabolism, so a negative result does not necessarily exclude exposure at an earlier time. Results are interpreted by the ordering professional.

• Phencyclidine (PCP) urine immunoassay screen
• Qualitative screen result relative to the laboratory cutoff
• Confirmatory phencyclidine by mass spectrometry when the screen is presumptive positive
• Phencyclidine concentration reported with confirmation
• Urine creatinine as a specimen validity measure
• Urine pH and specific gravity when specimen validity testing is included

Why people order this test

• Screen for phencyclidine exposure in an authorized testing setting
• Confirm a presumptive positive urine screen with a specific method
• Add laboratory information to a professional clinical evaluation
• Support an authorized workplace or program testing requirement
• Document PCP findings with a confirmed concentration when requested

How to prepare

No fasting is required for this test. A urine sample is collected at the lab according to its instructions. Inform the laboratory of any medications or supplements you take, since some can interfere with screening assays.

Understanding your results

Results are typically available within one to three business days. A negative screen means phencyclidine was not detected at the laboratory cutoff, while a presumptive positive result is confirmed by a specific method before it is considered final.