SAN DIEGO – Forensic toxicologist Donna Papsun spends her days with drugs, but she doesn’t see patients or try to make anyone better. Still, her work is crucial to every medical professional who needs to know which new illicit drugs their patients have been taking.

In Willow Grove, Pa., a suburb of Philadelphia, Ms. Papsun and her colleagues at NMS Labs develop screening tests for designer drugs that have just appeared on the black market or crossed the Drug Enforcement Administration’s (DEA) radar.

It’s not an easy task for a variety of reasons, not the least of which is the challenge of finding a sample of the drug in question, which can be difficult to accomplish – even if it is made legally.

As Ms. Papsun told an audience at the annual meeting of the American Psychiatric Association, she faced a unique obstacle last summer, when an elephant tranquilizer called carfentanil, a derivative of fentanyl, began to make headlines. The obstacle? The U.S.-Canada border.

She wanted to develop a test for the opioid but couldn’t start until she got a reference sample of the controlled substance from carfentanil’s only manufacturer, a firm in Canada. It took months. “Crossing an international border caused all sorts of problems,” she said.

New designer drugs are constantly hitting the market. They’re often especially appealing – and especially risky – because routine drug tests can’t detect them, at least not yet.

In an interview, Ms. Papsun talked about the challenges of trying to keep up with the drug makers – and users.

“Designer drug testing developed back in 2008 will not catch anything that is seen in today’s designer drug market,” she said. “Designer drug testing requires constant attention, assessment, resources, and updating.”

Question: How long does it typically take to create a test for a new strain of illicit drug?

Answer: This can take anywhere from 3 to 9 months, and potentially longer, and it depends on many factors. Once a new drug has hit the market, we check to see if there is certified reference material available. If there is, then we can start to develop a test. Development includes identifying a successful chemical extraction technique – isolating the drug in question from biological matrix such as blood or urine – as well as a platform that reliably detects the drug without falsely reporting positives.

After development, the test has to go through a process called validation, which is a series of experiments to prove that the developed method works rigorously, day after day, and provides the same results. This is very important in forensic toxicology, because our results may be involved in criminal and civil litigation and must stand up to the rigors of court.

Q: What are some examples of the types of drugs that you’ve had to develop tests for?

A: Just in the past year, we have developed tests for new designer opioids (including carfentanil, furanylfentanyl, acrylfentanyl, and U-47700), designer benzodiazepines (including etizolam, diclazepam, flubromazolam, and flubromazepam) and new designer stimulants (including n-ethyl pentylone and dibutylone).

We have a synthetic cannabinoid test that was developed for the first time back in 2010. That test has been redeveloped several times since then, because we constantly have to update the test to keep up with the rapid changes in market availability of substances.

Q: What are some of the challenges that you face in terms of getting samples of human fluids that you can test for the drugs?

A: Most of the samples we see are from either death investigation cases or driving-under-the-influence cases. Samples from intoxications at hospitals are important, because those data help [us] understand the concentrations of drugs at which people can survive. But often, if the patients survive, their biological specimens are not forwarded for specialized toxicology testing. Most hospital systems do not have the analytical capabilities to detect designer drugs, and most lack the resources to seek out the causal agent for an intoxication or apparent overdose.

Q: At the APA meeting, you talked about the risk that you’ll hear about a strain from the DEA, develop a test and find out it’s obsolete because the drug isn’t used anymore. Does that happen very often?

A: Yes. The problem with designer drugs is that there are so many, so you can spend a lot of time, money, and other resources dedicated to developing and validating a test for a drug that may or may not even be popular.

As a business, you have to make decisions regarding prioritization: Do we build a test for a drug that has only been reported once, or do we focus our efforts on a substance that has been reported dozens of times?

We certainly have spent time and resources developing a test that became obsolete, or never reported a positive case. For example, we developed a test for desomorphine, and we have never chemically confirmed desomorphine in a biological specimen. It definitely is hit or miss, but we spend a lot of time and research a lot of different avenues to make educated decisions regarding the substances we develop tests for.