Public Health Laboratory Newsroom
Testing Reveals Which Drugs Are Involved in Overdoses

When a person experiencing an overdose arrives in a hospital, clinicians must make quick decisions on proper treatment protocols. They base their decisions on the patient’s behaviors and symptoms and potentially on the information provided by the patient. Health professionals have often suspected they were working with inadequate and incomplete information when treating overdoses.

In 2017, the opioid epidemic claimed a then-record 421 Minnesotan lives. The problem extended beyond opioids alone; many overdoses resulted from a combination of substances. To gain more information, the Minnesota Department of Health initiated the Minnesota Drug Overdose and Substance Use Surveillance Activity (MNDOSA) project.

Recently, work done by the MNDOSA program was in the news in connection with a sudden rise in fentanyl-related overdoses involving the sedative xylazine and an increased use of another sedative, medetomidine. Both sedatives are animal tranquilizers and not approved for human use. See Minnesota sees spike in overdoses involving sedatives: "Naloxone isn't going to help" on CBS News.

What Is MNDOSA?

MNDOSA is a partnership between the Minnesota Department of Health and hospital systems in many of the Emergency Medical Services (EMS) regions throughout the state. When one of our partner hospitals provides care for a person experiencing an overdose, it sends a residual clinical sample of blood or urine to the Chemical Threats and Biomonitoring (CTB) Unit at the Minnesota Public Health Laboratory. All samples are de-identified, meaning that all individual patient information is removed. 

The CTB Unit then uses an advanced instrument, a liquid chromatography high resolution mass spectrometer (LC-HRMS), to detect the presence of more than 1,300 different compounds of interest in a single sample, including:

• Synthetic opioids (fentanyl, nitazines, etc.)
• Heroin
• Cocaine
• Methamphetamine and other amphetamine compounds
• Bath salts (cathinone, methylone, etc.)
• Synthetic cannabinoids
• Designer benzodiazepines (etizolam, etc.)
• Marijuana

The lab sends toxicology results to the site leads at partner hospital systems, who choose how best to disseminate the information internally. At the Minnesota Department of Health, MNDOSA’s results are used as population-level data, showing what substances are involved in overdoses, in which combinations, and in which areas of the state.  

Finding Deadly Combinations

Over the past eight years, the project has uncovered many important insights. Results show the rate and number of overdoses involving two or more substances have increased from 40% to 70%. Methamphetamine and opioids, most specifically fentanyl, are especially prevalent and have been detected in around 60% of all samples analyzed. The recent increase in the identification of xylazine and medetomidine have been detected predominately in fentanyl-positive samples.   

MNDOSA has revealed the inadequacy of the information doctors work with in overdose cases. For almost every category of illicit substances, doctors underestimated the percentage of patients with the drug in their system.

In the most general sense, MNDOSA has firmly established that opioids are not solely to blame for the recent increase in overdoses. By revealing the combination of substances at play, the program gives information to health professionals that is critical to addressing the latest patterns of abuse and to saving lives. 

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