The Fentalog Study: A Subset of Nonfatal Suspected Opioid-Involved Overdoses with Toxicology Testing

Fentanyl and its analogs (fentalogs) have increasingly contributed to opioid-involved overdoses across the United States. The Toxicology Investigators Consortium (ToxIC) and the Icahn School of Medicine at Mount Sinai are conducting a five-year project (2020-2025) examining fentalogs among nonfatal suspected opioid-involved overdoses, titled “Predicting Medical Consequences of Novel Fentanyl Analog Overdose Using the Toxicology Investigators Consortium (ToxIC)” (NIDA R01DA048009), referred to as “The Fentalog Study.” CDC provides supplemental funding to increase the project’s testing capacity.

The Fentalog Study utilizes data collected from 10 geographically diverse hospitals in 9 states to identify risk factors and evaluate optimal treatments for nonfatal overdoses involving fentanyl, novel fentalogs, and other substances* and to alert providers about trends in data. Patients presenting with a suspected opioid-involved overdose in any of the 10 study sites, with a leftover blood sample, are included for potential analysis. Approximately 30% of patients presenting with a suspected opioid-involved overdose in study sites have adequate leftover blood samples; samples are tested for a panel of 900+ substances,^* by the Center for Forensic Science, Research, and Education (CFSRE).

Using data from The Fentalog Study, this dashboard provides estimates of substances detected in samples from patients experiencing a suspected opioid-involved overdose. The dashboard will be updated biannually or as new data become available. These data can be used in combination with nonfatal drug overdose data from the CDC’s Drug Overdose Surveillance and Epidemiology (DOSE) system to improve understanding of drug use patterns in nonfatal overdoses.

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samples tested between … and …

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of samples tested contained fentanyl, either alone or with other substances.

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of samples contained ONLY fentanyl, with no other substances.

Percent of Samples Testing Positive for Selected Drug Classes^†

In study sites, blood specimens from patients who experienced a suspected opioid-involved overdose tested positive for fentanyl and fentanyl analogs (78%) of the time, more often than any other drug class.

Percent of Samples Testing Positive for Specific Drugs^†, grouped by Drug Class

Select a drug class to see which specific drugs in that class were most commonly found.

Percent of Samples Testing Positive for Selected Drug Combinations^§

In study sites, most blood samples tested positive for multiple substances*. Select “Common Two Substance Combinations” or “Common Three Substance Combinations” to see the substances found in combination most often.

Number of Adulterants^¶ per Sample Testing Positive for Fentanyl

In study sites, blood specimens from patients with a suspected opioid-involved overdose that tested positive for fentanyl often tested positive for adulterants^¶. These substances, combined with other illicit or prescription substances, can be harmful.

Footnotes:

*The term “substances” refers to drugs, adulterants, and contaminants.

^†Each sample can test positive for multiple drug classes and for multiple specific drugs.

^§A single sample can be counted in multiple combinations. Additionally, other substances are potentially present alongside the listed combinations.

^¶Adulterants are additives that increase the bulk-volume of the combined substances, or are physical, chemical, biological, or other substances that are chemically created in a lab with intent to “mimic” (or have similar effects of) another drug, such as marijuana, cocaine, or morphine. Examples of adulterants include xylazine, diphenhydramine, levamisole, and quinine. Adulterants can be harmful.

Data are not geographically representative of the entire United States. The Fentalog Study only includes patients meeting case criteria in 10 hospital sites across 9 states.
Combinations of drugs found in the patient’s blood may not be representative of the drug(s) they intended to take. Drugs may have been mixed together with or without the patient’s awareness.
The timing of when the patients took the drugs cannot be ascertained. Drugs found in combination may have been used at different times or may have been used together at the same time.

Access the latest guideline, data, and resources

The Fentalog Study: A Subset of Nonfatal Suspected Opioid-Involved Overdoses with Toxicology Testing

Percent of Samples Testing Positive for Selected Drug Classes†

Percent of Samples Testing Positive for Specific Drugs†, grouped by Drug Class

Percent of Samples Testing Positive for Selected Drug Combinations§

Number of Adulterants¶ per Sample Testing Positive for Fentanyl

Footnotes:

Percent of Samples Testing Positive for Selected Drug Classes^†

Percent of Samples Testing Positive for Specific Drugs^†, grouped by Drug Class

Percent of Samples Testing Positive for Selected Drug Combinations^§

Number of Adulterants^¶ per Sample Testing Positive for Fentanyl