RACING AHEAD: The Future of Drugs-of-Abuse Testing and Drug Toxicology Products

In June 2010, an alarming new trend report released by the Centers for Disease Control and Prevention (CDC) and the Substance Abuse and Mental Health Services Administration (SAMHSA) stated that the increase in misuse of prescription pain drugs has led to emergency department (ED) visits for prescription drug abuse equaling that of illegal drugs. More than 2 million ED visits in 2008 were as a result of misuse of prescription drugs. This trend, however, is not restricted to drugs of abuse (DOA) only. In fact, a recent 2009 FDA Drug Safety and Risk Management Advisory Committee report stated that overdose of acetaminophen, one of the most common over the counter (OTC) pain- and fever-reducing drugs in the United States, has been linked to liver-related damage, disease, and death.

Exceeding four times the recommended dosage can lead to severe liver damage. However, consumers bought 28 billion doses of acetaminophen, or combinations thereof, in 2005. It was also noted that many of these overdose cases were due to consumers inadvertently consuming more than the recommended dose. The FDA report adds, “From 1998 to 2003, acetaminophen was the leading cause of acute liver failure in the United States, with 48% of acetaminophen-related cases (131 of 275) associated with accidental overdose.”

Anne Becknell, director of marketing, DOA, at Alere, San Diego, agrees. “In fact,” she says, “we see this trend magnified among the elderly. They may accidentally take a second or even third dose, should they not remember. Even in nursing homes, where medications are controlled, chances of mistakes in drug doses are very high, especially with an OTC when the medical directives are unclear.”

Fabienne Le Floch, toxicology specialist at AB SCIEX, Foster City, Calif, added, “Five percent of the world’s total population over the age of 15 are using illicit drugs, and several hundred thousand drug intoxications are reported each year in the western world alone.” With this kind of rampant drug use, be it accidental or on purpose, forensic scientists and law enforcement agencies require screening methods used in forensic intoxication cases to be rapid and yet highly sensitive. And while officials reiterate the need for preventive measures—including education, patient and prescription restrictions, and handling and storage of such drugs—to be an important aspect in DOA and prescription drug handling, early detection of such compounds in a patient will enable appropriate and timely treatment in urgent care.

Challenges in Forensic Toxicology Laboratories

A typical analytical assay to detect multiple drugs at low doses would be one that could test multiple drugs from patient samples, even ones present in low concentrations while others are at high levels. This involves assay techniques exhibiting high specificity and sensitivity levels in detection.

The challenges in these laboratories are very obvious, but their effects have increased dramatically as newer “designer” drugs have entered the sample system (and patients). Increasingly, these compounds alter the patient’s behavior, and mental and physical state, and should they be present in low concentrations, they may be very difficult to detect.

Some of the obvious challenges, therefore, are:

new DOA derivatives;
shortage of forensic scientists; and
detection of low-dose designer drugs.

The Start: Immunoassays and Combinations

Siemens Healthcare, Malvern, Pa, has pioneered many of the techniques used in drug testing and therapeutic drug monitoring. Besides HPLC, GC, and LC/MS (liquid chromatography, mass spectrometry), it and other companies introduced immunoassay-based techniques such as RIA, PETINIA, and EIA.

According to Nancy Haley, PhD, scientific specialist at Siemens Healthcare, “Siemens pioneered drug screening from the very beginning of the 1970s when the White House called for a diagnostic test to help returning veterans of the Vietnam War. This was the beginning of an awareness (that today is called) ‘behavioral health.’ We understand the importance of reliable drug testing and are a market leader with a wide portfolio of reliable drugs of abuse and sample validity methods.”

Developed at Siemens, the Enzyme Multiplied Immunoassay Technique (EMIT) has been the go-to immunoassay technique for many years to measure miniscule amounts of drugs and drug metabolites in patient samples. The technology is based on target analyte-antibody binding site competition. Competitive binding of target versus drug enables an enzymatic absorbance change that can be measured photometrically. EMIT has been one of the most widely accepted techniques in forensic toxicology.

Speaking about the reliability and accuracy of the results, Haley states, “EMIT is the test you want to go to court with.” According to her, “Drug testing is all about people and their lives, and you want to make sure you receive the right answer. Siemens provides reliable solutions in drug testing.”

EMIT and other forms of the immunoassay have been modified to match the growing demands of testing for forensic drugs in patient samples contaminated with other drugs or patients with altered mental states. LC/UV in combination with EMIT has been an alternative to standard immunoassay techniques. Siemens has also made landmark development in releasing its Carbohydrate Deficient Transferin (CDT) test to detect a marker for alcohol intake. This test is a method for long-term, chronic alcohol abuse, which differentiates from “problematic” drinking habits.

Alere’s DSX System

The Rise of LC/MS/MS

In combination with EMIT testing is EMIT with GC-MS or LC-UV techniques, which lead to further detailed drug detection and analysis. And while these and other combinations of immunoassay techniques have been industry standard for many years, LC/MS/MS has been a standard in the pharmaceutical industry for many years.

In a 2007 article in Forensic magazine, Tania Sasaki, PhD, senior product applications specialist and small molecule group leader at Applied Biosystems, part of Life Technologies Inc, Carlsbad, Calif, noted the increase in use of LC/MS/MS techniques in forensic toxicology testing. While initial industry thought was that this technique was too costly, labor-intensive, and time-consuming, now this technique is routine and has proven to be extremely sensitive in detecting low doses of drugs in mixtures of patient samples.

As a bench instrument, in conjunction with the CliquidTM Drug Screen and Quant Software for Routine Forensic Toxicology (from AB SCIEX), LC/MS/MS allows for significantly less complicated sample derivatization, an increased range of analytes detection, and lesser time than GC/MS. In addition, the LC/MS/MS system is also lower in cost and time versus an LC/UV system ($2.50 per test post setup, versus $19.50 for LC/UV). In addition, LC/MS/MS techniques also have enabled analysis of benzodiazepines and zolpidem from urine with significantly higher sensitivity than LC/UV. Analytical run time is 6 minutes, at 25 ng/mL cutoff in a 0.5-mL sample size, reducing cutoff in half, for a sample at half the original size.

Le Floch describes the technology and its importance in forensic detection. “Increasingly, innovative LC/MS/MS methods are being used in place of conventional analysis for comprehensive drug screening, drugs-of-abuse analysis, or general unknown screening. Toxicology laboratories throughout the world are discovering the analytical power of LC/MS/MS and its ability to accurately identify and quantify minute amounts of compounds in complex sample matrices such as blood, urine, and oral fluid,” she says.

“AB SCIEX is working closely with toxicology laboratories throughout the world to develop these and other applications for this fast, sensitive, and robust technology. Our unique hybrid triple-quadrupole linear ion-trap (QTRAP System) technologies enable rapid screening, identification, and quantitation of hundreds of compounds in a single analysis. In addition to unique hardware technology, we provide enhanced software solutions to simplify the use of LC/MS/MS for routine testing as well as preconfigured methods enabling the toxicologists to generate accurate and precise results faster.

“Today, LC/MS/MS for forensic toxicology is the preferred method of analysis over traditional analysis techniques for both qualitative and quantitative analysis. Offering a solution that provides better sensitivity, LC/MS/MS requires less sample preparation and no derivatization, in less time.”

AB SCIEX’ LC/MS/MS technology consists of hybrid triple-quadrupole linear ion-trap technologies that enable rapid screening, identification, and quantitation of hundreds of compounds in a single analysis. According to its experts, the company’s QTRAP System technology allows toxicologists to identify, quantitate, and confirm more than 300 drugs in a single analysis; shortens analysis time; and gives toxicologists more useful information from every experiment.

In combination, its Cliquid 3.0 Software simplifies LC/MS/MS for routine testing since it is built with an intuitive point-and-click interface and four-step workflow, yielding a simplified process flow and easier result generation. And finally, the AB SCIEX iMethod Test for Drugs of Abuse Screening provides a set of generic DOA screening methods to analyze hundreds of compounds in both positive and negative mode, with up to six transitions per compound, allowing for customized tests.

The Need for Rapid Testing

While innovative leads in technologies related to LC or GC or even MS are in high demand in laboratories, drug toxicity tests need to be rapid and accurate to save a patient in an emergency or urgent care setting. Most of the techniques developed and discussed earlier are accurate and sensitive, but they are not easily used in an ED setting.

Becknell says, “The greatest strength for Alere is its ability to place their Triage® TOX Drug Screen test in an ER setting.”

When there is a clinical presentation of altered mental status, chest pain, trauma, coma, or respiratory overdose with possible overdose and/or seizure in a patient in the ED, accurate diagnosis is imperative. This is possible in an ED setup only if the test is rapid, result turnaround time is quick, and the antidote to a possible drug toxicity or overdose is administered in time. The Triage TOX Drug Screen is a fluorescence immunoassay, used with Triage Meters for a qualitative determination of drug or major metabolites above the threshold of up to 10 distinct drug classes.

These assays include acetaminophen, amphetamines, methamphetamines, barbiturates, benzodiazepines, cocaine, methadone, opiates, THC, and tricyclic antidepressants. The tests are done in urine samples, in about 15 minutes. With a built-in QC chip, this test saves time and money, with a simple assay read.

According to Becknell, “Alere analyzers are used not only in laboratories, but primarily in triage facilities, for faster screening. Big-footprint analyzers can get bogged down by the technology, which is where the Triage Meter has an advantage to faster screening. Especially when patients come in to ER with altered mental status, it is imperative to detect what is causing that, to save the nurses time in detection, reduce patient anxiety, and apply antidotes if necessary.”

Unique to Alere, Triage TOX Drug Screen is the only urine-based qualitative assay available. So instead of transferring samples to laboratories, these samples can be collected at the ED by nurses and tested within 15 minutes of patient admission.

The Alere Triage assays have been designed with the specificity and sensitivity necessary to provide drug screen results to aid the physician in the diagnosis of patients, primarily geared toward emergency situations where turnaround time is essential.

The Future of DOA Testing

While rapid tests are greatly desired for quicker physician decision and patient care, more elaborate serum (or other body fluid)-based testing is still in demand for accurate determination and diagnosis. Siemens is working to provide a better detection platform. According to its experts, there is a growing demand for reliable drug testing solutions as it recognizes that behavioral health is a global, yet underestimated, challenge. Siemens is currently working on the EMIT 6-Acetyl-morphine assay to meet those challenges.

Alere provides a wide selection of drug screening products, each geared toward a specific market need, from rapid lateral flow cassettes and cups to interfaced instrumented assays to reference and SAMHSA-certified laboratory-based screening, confirmation, and specialty testing.

To stay up to speed on drug testing products, bookmark this website.

Says Le Floch, “Often, just when toxicologists think their database of drug information is up to date, a new drug or derivative arrives but can easily be missed. Our QTRAP system rapidly identifies metabolites of new DOAs and hence is a critical tool in the battle against this new global trend.”

While for an outsider the detection of minute traces of drugs and designer compounds appears to be a simple process, forensic scientists have to work harder to improve the techniques to detect a fresh wave of compounds reproducibly, reliably, and rapidly. That is the future of detection, diagnosis, and, ultimately, patient care.

Madhushree Ghosh, PhD, is a San Diego-based science and health writer.

RACING AHEAD: The Future of Drugs-of-Abuse Testing and Drug Toxicology Products