Unpredictability of Counterfeit Drugs

Clinical Update
January 2022

Unpredictability of Counterfeit Drugs

Novel Psychoactive Substances (NPS) are developed to bypass controlled drug legislation and evade detection by traditional drug testing methods. In many cases they are labelled as “research chemicals” and/or “not for human use.” A new trend is to package NPS as counterfeit versions of common prescription drugs in an effort to make the unauthorized possession of these substances seem less suspicious. The most observed counterfeit exhibits seized by law enforcement are mimics of common prescription opiates, benzodiazepines, and stimulants. These pose a particular danger for pain management or behavioral health patients if ingested, as the tablets rarely, if ever, contain the drug they are intended to mimic. In addition to these patient groups, other individuals who are not under active medical care may purchase counterfeit drugs over the internet for non-medical use. The information provided below is a limited sampling of counterfeit drugs which have been seized by law enforcement.     

Counterfeit Opioids
In most cases, counterfeit opioids are made to resemble oxycodone, hydrocodone/acetaminophen, or oxycodone/acetaminophen dosage forms and rarely, if ever, contain the mimicked drug. Currently, the most commonly observed counterfeits are counterfeit oxycodone 30mg tablets.

Counterfeit oxycodone containing fentanyl1


Counterfeit hydrocodone/acetaminophen containing fentanyl and promethazine2

These counterfeit opioids play a role in overdose deaths, with the most commonly observed drug identified in these tablets being illicitly manufactured fentanyl (IMF). IMF is analytically similar to prescription fentanyl, but is typically created utilizing different methods, which introduces opportunities for contamination or adulteration. Additionally, fentanyl analogs (fentalogs) have been introduced into the illicit drug supply over the last decade, which may be more or less potent than IMF. While IMF and fentalogs have been most prevalent, newer classes of designer opioids are emerging in the global illicit drug supply. One such class is the nitazenes, of which isotonitazene is the most detected.  

Counterfeit Benzodiazepines
The most commonly encountered counterfeit benzodiazepine is alprazolam, with the contents of the tablet varying significantly. In most cases they contain a designer benzodiazepine(s), such as flualprazolam1,3 but, in select cases, they have been found to contain opioids such as IMF.4 For the opioid-naïve individual, this poses a significant risk for overdose.   

Counterfeit alprazolam containing flualprazolam1


Counterfeit alprazolam containing etizolam and fentany4


Counterfeit diazepam containing flubromazolam and diazepam5

As with the designer opioids, the potency of designer benzodiazepines relative to prescription benzodiazepines is largely unknown and the true contents are usually unknown to the ultimate user.    

Counterfeit Stimulants
There have been numerous reports of large quantities of counterfeit amphetamines seized by the DEA1. In most cases they contain methamphetamine instead of the intended amphetamine, but they have contained cocaine as well as IMF in some cases. As with counterfeit benzodiazepines, in an opioid-naïve individual, the presence of IMF may lead to an overdose.

Counterfeit amphetamine containing methamphetamine1

In many cases, counterfeit versions of the medications look nearly identical to the substance they are intended to mimic. This can lead to accidental exposure to dangerous drugs, such as IMF. It is important to stress that patients only take their medication which is directly obtained from a licensed dispenser, such as a pharmacy. Any drug obtained from any other source may be a counterfeit and lead to dire circumstances if ingested.   

Aegis’ test offerings are developed to allow providers the ability to identify potentially problematic substance use and afford them the opportunity to provide more informed care and minimize the potential for these unregulated substances to contribute to adverse events, including overdose deaths. NPS testing is offered for both urine and oral fluid specimen types. 

NOTICE: The information above is intended as a resource for health care providers. Providers should use their independent medical judgment based on the clinical needs of the patient when making determinations of who to test, what medications to test, testing frequency, and the type of testing to conduct.



1. US Drug Enforcement Administration. DEA 2020 National Drug Threat Assessment. March 3, 2021. Available at: https://www.dea.gov/documents/2021/03/02/2020-national-drug-threat-assessment. Accessed December 30, 2021.
2. Vo KT, van Wijk XM, Lynch KL, Wu AH, Smollin CG. Counterfeit Norco Poisoning Outbreak — San Francisco Bay Area, California, March 25–April 5, 2016. MMWR Morb Mortal Wkly Rep 2016;65:420–423. DOI: http://dx.doi.org/10.15585/mmwr.mm6516e1
3. Blumenberg A, Hughes A, Reckers A, Ellison R, Gerona R. Flualprazolam: Report of an Outbreak of a New Psychoactive Substance in Adolescents. Pediatrics. 2020;146(1):e20192953. doi:10.1542/peds.2019-2953
4. Arens AM, van Wijk XM, Vo KT, Lynch KL, Wu AH, Smollin CG. Adverse Effects From Counterfeit Alprazolam Tablets. JAMA Intern Med. 2016;176(10):1554-1555. doi:10.1001/jamainternmed.2016.4306
5. European Monitoring Centre for Drugs and Drug Addiction (2021), New benzodiazepines in Europe – a review, Publications Office of the European Union, Luxembourg.  https://www.emcdda.europa.eu/system/files/publications/13759/TD0221596ENN_002.pdf