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Updated: Jun 24, 2026
10:13
Fentanyl Analog Screening using LC-TIMS-TOF MS/MS
Published on: November 8, 2024
Acute fentanyl toxicity: from opioid-induced to hypoxia-mediated pathophysiology
Tristan Lewis1,2, Annick Haouzi3, Amanda Reinhardt1,2
1Department of Neurosciences, Cleveland Clinic Research, Cleveland, Ohio, United States.
Journal of Neurophysiology
|June 23, 2026
Summary
Fentanyl overdose deaths are driven by an oxygen (O2) crisis, not just respiratory depression. This involves reduced O2 delivery and increased consumption, leading to hypoxia unresponsive to naloxone.
Area of Science:
- Pharmacology
- Physiology
- Toxicology
Background:
- Acute fentanyl toxicity is often oversimplified as solely respiratory depression.
- This perspective overlooks distinct fentanyl effects and oxygen delivery/consumption dynamics.
Purpose of the Study:
- To propose an integrated framework for understanding fentanyl lethality based on oxygen delivery (DO2) physiology.
- To elucidate the mechanisms of fentanyl-induced oxygen mismatch and its consequences.
Main Methods:
- Review of existing literature on fentanyl's physiological effects.
- Integration of central toxicities (apnea, rigidity, cardiovascular depression) into a DO2/V̇O2 framework.
Main Results:
- Fentanyl causes a rapid DO2/V̇O2 mismatch via central apnea, muscle rigidity, and cardiovascular depression.
- Hypoxia shifts pathophysiology, leading to positive feedback loops unresponsive to naloxone.
- Endogenous defenses exist but require timely restoration of DO2.
Conclusions:
- Fentanyl lethality is an oxygen crisis resulting from a DO2/V̇O2 mismatch.
- Therapeutic strategies must address the complete oxygen mismatch, not just hypoventilation.
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