Urine Drug Screens to Monitor Opioid Use for Managing Chronic Pain

A 53-year-old woman presented for a prescription refill of hydrocodone/acetaminophen 10 mg/325 mg. She had chronic low back pain and partial paralysis from a thoracic spinal cord infarction, secondary to aortic dissection from prior cocaine use. Taking 2 to 3 tablets of hydrocodone/acetaminophen daily improved her back pain from 5 to 2 on a 10-point scale. She reported no recent illicit substance or drug use and stated her last dose of hydrocodone was that day. The patient had not achieved pain control with prior nonopioid pharmacologic pain management, including duloxetine and gabapentin. Although past cocaine use was a risk factor for opioid misuse, a trial of hydrocodone was initiated, after discussion of risks and benefits, with a plan for careful monitoring. The state prescription drug monitoring program showed no other prescribers of controlled substances. A urine immunoassay drug screen was ordered to evaluate for medication misuse and illicit use (Table).