Laboratory Testing for Prescription Opioids

Abstract

Opioid analgesic misuse has risen significantly over the past two decades, and these drugs now represent the most commonly abused class of prescription medications. They are a major cause of poisoning deaths in the USA exceeding heroin and cocaine. Laboratory testing plays a role in the detection of opioid misuse and the evaluation of patients with opioid intoxication. Laboratories use both immunoassay and chromatographic methods (e.g., liquid chromatography with mass spectrometry detection), often in combination, to yield high detection sensitivity and drug specificity. Testing methods for opioids originated in the workplace-testing arena and focused on detection of illicit heroin use. Analysis for a wide range of opioids is now required in the context of the prescription opioid epidemic. Testing methods have also been primarily based upon urine screening; however, methods for analyzing alternative samples such as saliva, sweat, and hair are available. Application of testing to monitor prescription opioid drug therapy is an increasingly important use of drug testing, and this area of testing introduces new interpretative challenges. In particular, drug metabolism may transform one clinically available opioid into another. The sensitivity of testing methods also varies considerably across the spectrum of opioid drugs. An understanding of opioid metabolism and method sensitivity towards different opioid drugs is therefore essential to effective use of these tests. Improved testing algorithms and more research into the effective use of drug testing in the clinical setting, particularly in pain medicine and substance abuse, are needed.

Characterizing the Interrelationships of Prescription Opioid and Benzodiazepine Drugs With Worker Health and Workplace Hazards

“…134 However, PD use may not be detected in most programs, as the results of the drug test are reported to the employer as negative, if a legitimate prescription is supplied. 134,135 Legitimate does not mean lack of adverse effects, however, as approximately 60% of all opioid analgesic overdoses occur among patients who have a legitimate prescription. 134,136 Indications that marijuana use may vary inversely with opioids use was suggested by an ecological study showing that states with medical cannabis laws saw 24.8% lower mean annual opioid overdose mortality rate (−37.5% to −9.5%; P = 0.003) than states without these laws.…”

Evaluation of potential occupational exposures to opioid drugs during an emergency medical services response (interim report).

“…Screening assays do not detect all opioids equally well. Fentanyl is sufficiently different in chemical structure from the opiate morphine that tests that specifically look for fentanyl are necessary to detect it [Keary et al 2012;Milone 2012]. The timing of urine collection relative to the time of exposure can also affect the urine testing results.…”

Acute Pain Management in Hospitalized Adult Patients with Opioid Dependence: A Narrative Review and Guide for Clinicians

“…Gas chromatography/mass spectrometry is the most sensitive and specific type of urine screen and can be ordered to confirm a prescribed opioid if needed. 26 Pain management should begin with calculating the TDD of oral opioids that the patient was taking prior to admission, and converting to morphine equivalents. For moderate acute pain, TDD can be increased by 25% to 50%.…”