Controlled substance monitoring and other drug testing give clinicians valuable information about how patients adhere to treatment regimens or might be misusing or even abusing drugs. But keeping up with a continually changing drug testing environment challenges most clinicians. New drugs—sold illicitly—keep coming to market. Meanwhile, testing methods have variable performance, and drug testing recommendations evolve. Given all these factors, clinicians need help not only understanding how tests work and how the body metabolizes drugs but also reminders that laboratorians are partners in patient care, according to laboratorians specializing in drug monitoring and toxicology.
“Sometimes physicians can underestimate the complexity of the current drug testing environment,” said Jaime Noguez, PhD, director of chemistry and toxicology at University Hospitals Cleveland Medical Center and assistant professor of pathology at Case Western Reserve University. “You can’t just rely on a one-size-fits-all approach to drug testing,” Noguez added. She urged laboratorians to work with physicians to make sure labs offer useful drug tests, education, and resources.
Defining Knowledge Gaps
Misunderstanding of assays’ advantages, disadvantages, and limitations drives inappropriate drug orders, said William Clarke, PhD, DABCC, FAACC, professor of pathology at Johns Hopkins University School of Medicine in Baltimore and co-author of the AACC Academy’s practice guideline on monitoring pain management drugs. For example, clinicians who know that an opiate assay will test for presence of various drugs might not realize the assay does not differentiate between morphine and heroin.
Providers also have varying degrees of understanding of drugs’ metabolic pathways.
Some clinicians might dismiss results that seemingly make no sense and want to retest patients. Labs should encourage conversations about potential reasons for odd results. David Colantonio, PhD, DABCC, FAACC, listed a few: genetic polymorphisms, slow-clearing metabolite products, differences in speed of metabolism, or co-administration of drugs that cross-react with an assay. With mass spectrometry (MS) testing especially, labs can measure parent compounds and metabolites and tease out reasons for discrepant results, added Colantonio, clinical biochemist at The Ottawa Hospital, lab director at Pembroke Regional Hospital, and assistant professor of pathology and laboratory medicine at the University of Ottawa in Ontario, Canada.
Kara Lynch, PhD, warned of another potential pitfall for both clinicians and laboratorians: outdated immunoassay panels that test for illicit drugs no longer common in an area. Labs with public health responsibilities should review their panels against current reality, said Lynch, who is an associate clinical professor at University of California San Francisco (UCSF) and co-director of the core laboratory at Zuckerberg San Francisco General Hospital and Trauma Center.
Setting Up Success
Labs have many tactics for driving appropriate test orders. At Mayo Clinic in Rochester, Minnesota, clinicians soon will be able to order drug screens via an order entry system driven by algorithms to arrive at the best orders. They will answer a series of questions that lead them to appropriate tests, said Loralie Langman, PhD, DABCC, director of the clinical and forensic toxicology laboratory at Mayo, and Paul Jannetto, PhD, DABCC, MT(ASCP), FAACC, co-director of Mayo’s toxicology and drug monitoring lab and metals laboratory. Both are co-authors of the AACC Academy’s practice guideline on monitoring pain management drugs.
Mayo’s lab report prominently displays interpretive information stating results are consistent with use of particular drugs within the last 3 days. That way, clinicians get the most important information even if they don’t read the entire list of analytes and associated results, Langman noted.
At UCSF, Lynch’s lab simplifies clinician ordering with a choice of a urine drug screen, a comprehensive MS test with hundreds of compounds, and a list of individual immunoassays. Rules and automatic reflex testing are written into urine test ordering processes and differ by needs of different locations and departments. For example, screening orders from the emergency department (ED) and inpatient units do not get automatic MS confirmatory testing because patients usually are gone before results are ready. Meanwhile, positive urine screen results from clinics automatically reflex to confirmatory testing because clinics might be checking for compliance to prescribed medications. Some immunoassay tests prone to false positives—like a test for amphetamine—are also reflexed to confirmatory testing.
Lynch’s lab uses MS for confirmatory testing more sparingly than reference labs because Zuckerberg San Francisco General serves a public health role and operates within a limited budget, she added.
Noguez’s lab has a dedicated phone line and email address that pathologists monitor daily to answer questions about test selection and result interpretation in one-on-one conversations with physicians, nurses, and medical assistants. She also gives lectures. Some are recorded and posted online, along with guides to ordering the right test for specific clinical indications and educational and reference documents. They cover topics such as drug detection windows in urine and blood, differences in cutoffs for screening and confirmatory drug tests, and metabolism pathways for common drugs.
Noguez also participates in a health system-wide drug testing oversight committee with laboratory staff, hospital leadership, and practicing clinicians in various specialties. The committee discusses test utilization and new testing needs and works together to design new drug panels. The goal is to arrive at consensus before rolling out new tests and workflows, Noguez explained.
Clinical laboratorians also use data to support testing decisions and communications with clinicians. For example, Noguez regularly uses lab information system (LIS) data on test volume and utilization to guide test menu and workflow changes. Data that show inappropriate ordering by certain physicians or groups can be fodder for educational discussions about proper test utilization, said Jannetto and Langman. Data also inform establishment of hard stops to inappropriate ordering by particular groups, Noguez added.
Colantonio uses various groups’ data in discussions with them about how to set up workflows for the new MS lab, which will not be automated.
Noguez also pulls LIS data to learn about local positivity rates for prescription and illicit drugs in various patient populations. Data patterns can reveal new drugs of abuse and trends in older ones and inform care by ED, pain management, and addiction specialists, Colantonio noted.
Lynch, whose hospital offers high-resolution testing for acute drug poisoning, uses LIS data to graph the prevalence of drugs that UCSF’s tests target. She also uses outside data on local drug use and overdoses. The data come from a collaborative group including her local poison control system, public health department, medical examiner’s office, city toxicology lab, and needle exchange programs, which monitor local drug use and overdoses. All these partners share information.
Building relationships and rapport with physicians and other staff is key to educating them and achieving proper test utilization. All the individuals CLN interviewed emphasized the importance of accepting opportunities to discuss drug testing and participating in hospital initiatives related to optimizing utilization.
Lab tours “are an amazing way to build professional bridges with various types of staff,” including clinical groups, pharmacists, and nurses who are often unaware of lab processes, Colantonio added. Tours include explanations of different aspects of the lab’s workflow and of what goes into validating tests and monitoring their quality. Colantonio spends extra time in areas of the lab especially of interest to a group.
The tours also spur trust and understanding when LIS problems delay results, openness to discussing discrepant results, and specific questions about test variability and measurements. Conversations have even led to a few published case studies, including one about a high-dose phenobarbital that can convert to its prodrug primidone (Ther Drug Monit 2013;35:145–9).
Leading physician rounds is an excellent way to find out what clinicians need. When Colantonio reads an article that speaks to questions he commonly encounters in rounds, he will send it to interested parties. Residents especially like his handouts with tables of common cross-reactions, he noted.
Clarke stays plugged into clinical groups that need education. In collaboration with pain management and addiction specialists, he helped develop Johns Hopkins’ standards and guidelines for pain management. By request, he speaks about available tests and their limits at the hospital’s regularly scheduled pain conference and during grand rounds.
Colantonio and Noguez also suggested involving clinicians from various specialties on lab utilization committees. They can tell labs what tests are not helpful, which new tests might be, and can give valuable insights that lead to effective changes in ordering. In addition, Colantonio recommended offering tailored trainings to emergency, clinical pharmacology, and toxicology residents, both via lectures and one-on-one interactions. Clarke also favors the one-on-one approach, especially when offered proactively. “Be old fashioned. Go to them,” he advised.
“You have to understand clinicians’ needs. Sometimes you don’t know what they don’t know,” Clarke added. He has worked at his institution for 20 years and is “still meeting groups of clinicians I need to connect with.”
Deborah Levenson is a freelance writer in College Park, Maryland. +Email: [email protected]