Legal Weed?
Written by Barry K. Logan, Ph.D., DABFT   
NMS Labs synthetic marijuana cannabinoids drugs k2
Although they are labeled "not for consumption" and bear a closer resemblance to potpourri than pot, commercially available synthetic cannabinoid drugs are purchased by users with the goal of obtaining a high similar to that caused by THC, found in marijuana. (Images: NMS Labs)

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IF YOU HAVE BEEN in a small convenience store or gas station, you are probably accustomed to seeing the packets of energy drinks and pills that surround the cash registers. Over the last two years, another category of products has started to appear beside them: Marked as “incense” and consisting of potpourri-like material in small foil or Mylar sachets, these may appear to be harmless novelty items. But they are far from that.

These products, sometimes referred to as “legal highs” or “fake weed”, usually contain synthetic cannabinoid compounds, and sometimes other psychoactive drugs.

The synthetic cannabinoid drugs were developed in the 1990s as potential therapeutic agents because of their anti-nausea and appetite-stimulating effects. They also act on the same brain receptors as marijuana. Starting in 2009, chemists in clandestine drug labs in Asia and eastern Europe began synthesizing these drugs and packaging them for recreational use.

These chemicals belong to a class of drugs called benzoyl or naphthoyl alkyl indoles, and go by names like JWH-210, AM-2233, WIN48,098, and others. (The letters indicate the laboratories where the compounds were first synthesized.) The chemicals are sprayed onto inert botanical material—including dried-and-crushed stems, leaves, and petals of common plants—and sold for the purposes of burning and smoking. The drugs have also been identified in both liquid and powder form.

The drugs produce effects that are very similar to those caused by marijuana, including increased pulse and blood pressure, watery bloodshot eyes, muscle tremors and tics, and lack of convergence of gaze. Like marijuana, they produce feelings of intoxication, lightheadedness, problems with balance and coordination, and appetite stimulation. They differ from marijuana by producing a greater amount of anxiety and agitation that can lead to adverse events such as emergency-room visits and police contacts.

Already, the use of these drugs has come up in trial in courts-martial, assaults, and DUI cases.
In spite of the fact that these drugs act in the same areas of the brain as THC (which is the active component in marijuana) they are quite different chemically. This represents challenges for crime laboratories:

  • First, the plant materials used as a vehicle for the drug are quite diverse, so there is a lack of morphological characteristics (such as cystolithic hairs) that allow the preliminary screening of marijuana.
  • Second, there are no reliable field color tests for synthetic cannabinoids as there are for cocaine, opiates, and stimulants.
  • A final challenge for the drug identification laboratory is the wide range of chemicals that are being used in these products, and the fact that these change on a weekly basis. As governments have moved to ban or control these chemicals, the laboratories that produce them can quickly turn out novel compounds with slightly different chemical structures in an attempt to circumvent the law.

In 2011, the United States Drug Enforcement Administration (DEA) temporarily classified five of these compounds as Schedule I Controlled Substances—the same category as heroin. The market quickly changed and these scheduled compounds are now less popular, having been replaced with chemical analogs.

In the spring of 2012, Congress was considering legislation that would attempt to schedule compounds by chemical class rather than individual structures. This could make it more difficult for clandestine labs to introduce compounds that skirt the law.

This rapid turnover in the analytical targets means that crime laboratories may not have the spectra of the compounds in their analytical libraries for mass-spectral identification—and so they may not recognize the identity of the drug. An additional challenge for law enforcement agencies is that even when these novel drugs are identified, if they are not scheduled in that particular state or by the federal government, most crime laboratories will report simply that no controlled substances were detected.

The adverse effects of the drugs are just beginning to be understood, and there are ever-increasing demands for toxicological testing in blood or urine. Numerous reports of adverse reactions to the drugs—including tachycardia, hypertension, vomiting, agitation, and hallucinations—are being reported in hospital emergency rooms and poison-control centers. There are reports of individuals under the influence of the synthetic cannabinoids becoming violent and committing assaults or injuring themselves. Increasingly, a role for the drugs in contributing to cause of death has been raised where otherwise healthy people with no medical history and no injury or illness have died shortly after using the drugs.

Toxicologically, the drugs present challenges also:

  • First, they do not cross-react on the immunoassay tests used to screen for marijuana use. These tests are relied on by many toxicology and hospital laboratories as the first step in their drug-screening procedure.
  • Additionally, the drugs’ chemical and pharmacological properties are such that they are present in blood at low concentrations following recreational use and do not extract readily or chromatograph well enough to be detected in the most common gas chromatography-mass spectrometry procedures used in routine drug testing.

Furthermore, the parent drug is not excreted into human urine. The compounds go through some extensive metabolic changes, hydroxylation, carboxylation, and glucuronidation—requiring additional steps in sample preparation before they can be detected. Consequently, synthetic-cannabinoid use goes undetected in many cases unless specific targeted tests are performed. The most appropriate techniques for detection of synthetic cannabinoids are liquid chromatography with tandem or time-of-flight mass spectrometry. This approach eliminates the need for derivatization, and offers the necessary sensitivity for forensic applications.

As toxicology laboratories have gained more experience with these drugs, we have collected larger databases of the many metabolites and biomarkers that can indicate synthetic cannabinoid use. We have refined analytical techniques to optimize the recovery and detection limits for the most common markers, and continue to monitor the drug-user marketplace to ensure that forensic laboratories are keeping up with the suppliers.

About the Author

Dr. Barry K. Logan is Director of Forensic and Toxicological Services for NMS Labs in Willow Grove, Pennsylvania. NMS Labs is an independent forensic laboratory, leading the nation in innovative tests for new and emerging therapeutic and abused drugs. Logan also teaches, lectures internationally, and conducts research in this area. In 2012 he was elected President Elect of the American Academy of Forensic Sciences. For more information, go to:

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