
Summary: Fentanyl exposure produces specific EEG signatures in the brain. The results also revealed that the drug impairs people’s breathing four minutes before noticeable changes in alertness.
Source: mass general
Fentanyl is used to supplement sedation and to relieve severe pain during and after surgery, but it’s also one of the deadliest drugs in the opioid epidemic.
In research conducted by researchers at Massachusetts General Hospital (MGH) and published in Nexus PNAStests of electrical brain activity revealed the effects of fentanyl over time and indicated that the drug stopped people’s breathing before other noticeable changes and before they passed out.
In the study, electroencephalogram (EEG) tests were performed for 25 patients undergoing general anesthesia for surgeries lasting 2 hours or more. The researchers found that certain EEG patterns were associated with breathing, sedation, and loss of consciousness.
“We found that fentanyl produces a specific EEG signature distinct from other anesthetic drugs, which may allow its effects to be monitored to enable safer, more precise, and personalized opioid administration,” says lead author Patrick L. Purdon, PhD, from the Nathaniel M. Sims Endowed Chair in Anesthesia Innovation and Bioengineering at MGH.
“For example, think of patients with COVID-19 who are sedated in intensive care or patients undergoing surgery – currently there is no way to know if opioids work in these unconscious patients.”

Purdon and colleagues’ EEG tests also revealed that fentanyl begins to impair breathing about 4 minutes before any change in alertness and at drug concentrations 1,700 times lower than those that cause sedation.
“That explains why fentanyl is so deadly: it stops people’s breathing before they even realize it,” Purdon says.
The results clearly indicate that no amount of fentanyl would be safe outside of a clinical setting with trained specialists. Given that exposure to fentanyl is likely to remain a persistent risk during illicit use, the rapid respiratory depression observed by researchers warrants the need for increased availability of medical observation or supervision units, naloxone and other tools to reduce the risk of death in drug users. disorder.
Additional co-authors include Gustavo A. Balanza, Kishore M. Bharadwaj, Andrew C. Mullen, Amanda M. Beck, Erin C. Work, Francis J. McGovern, Timothy T. Houle, and Eric, T. Pierce.
Funding: This work is supported by funds from the National Institutes of Health through a grant from the National Institute on Drug Abuse.
About this neuropharmacology research news
Author: Mckenzie Constituencies
Source: mass general
Contact: Mckenzie Constituencies – Mass General
Image: Image is in public domain
Original research: Free access.
“An EEG biomarker of fentanyl drug effects” by Patrick L. Purdon et al. Nexus PNAS
Summary
An EEG biomarker of fentanyl drug effects
Opioid drugs influence several brain circuits in parallel to produce analgesia as well as side effects, including respiratory depression. At present, we do not have real-time clinical biomarkers of these brain effects.
Here we describe the results of an experiment to characterize the electroencephalographic signatures of fentanyl in humans. We find that increasing concentrations of fentanyl induce a frontal theta band signature (4-8 Hz) distinct from sleep- and sedation-related slow delta oscillations.
We also report that respiratory depression, quantified by the drop in an instantaneous minute ventilation index, occurs at concentrations ≈ 1700 times lower than those that produce sedation as measured by reaction time.
The EEG biomarker we describe could facilitate real-time monitoring of opioid drug effects and enable more precise and personalized administration of opioids.