Urine Drug Testing of Chronic Pain Patients. V. Prevalence of Propoxyphene Following its Withdrawal from the United States Market.

The article focuses on a study that examines the levels of propoxyphene drug in the urine samples obtained from the U.S. pain management population (PMP). It mentions that propoxyphene, the opioid analgesic, was withdrawn from the U.S. market in November 2010 due to safety and efficacy issues. However, the urine analysis of PMP indicates the presence of propoxyphene, measured by a validated liquid chromatography–tandem mass spectrometry procedure.