Mapping the Metabolic Fate of Suzetrigine in Equine and Camel Models: A Step Toward Reliable Antidoping Detection.
Abstract: Effective pain management remains a persistent challenge, with opioids limited by tolerance, dependence, respiratory depression, and misuse. This has created demand for safer, nonaddictive alternatives. Suzetrigine (VX-548, Journavx) is a novel analgesic with promising efficacy, but its potential misuse in competitive racing requires investigation. Limited information is available on its metabolism and detection, emphasizing the need for metabolic characterization to aid antidoping strategies. Methods: In vitro metabolism of suzetrigine was evaluated using equine liver microsomes and homogenized camel liver. Metabolic profiling was carried out using high-resolution LC-HRMS. Fragmentation analysis was performed to assign metabolite structures and characterize biotransformation pathways. Results: Seven phase I metabolites (M1-M7) were identified, primarily via hydroxylation, methylation, demethylation, detrifluoromethylation, and cleavage of the pyridine-2-carboxamide moiety. One phase II metabolite (M8), formed by sulfation of the demethylated metabolite M5, was detected exclusively with camel liver. Metabolite structures were tentatively assigned based on mass fragmentation data, which showed characteristic neutral losses and diagnostic ions. Comparative analysis revealed that both species shared common phase I pathways, but camel liver demonstrated additional conjugation capacity. Conclusions: This study provides the first comprehensive characterization of suzetrigine metabolism in equine and camel liver systems. The results underscore metabolic variations, propose a biotransformation pathway, and offer crucial insights to support the development of antidoping detection strategies.
© 2025 John Wiley & Sons Ltd.
Publication Date: 2025-10-01 PubMed ID: 41029173DOI: 10.1002/rcm.10147Google Scholar: Lookup
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- Journal Article
Summary
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Research Overview
- This study investigates how the novel analgesic suzetrigine is metabolized in horse and camel liver models to better understand its breakdown products and improve antidoping detection methods for competitive racing.
Background and Significance
- Opioid painkillers, while effective, have significant drawbacks such as tolerance, dependence, respiratory issues, and misuse risk.
- There is a strong demand for safer, nonaddictive pain management options.
- Suzetrigine (VX-548, Journavx) is a new analgesic showing promise but poses a potential risk for misuse in animal racing competitions.
- Currently, little is known about how suzetrigine is metabolized or how to detect it reliably in biological samples.
- Understanding metabolism is critical to developing antidoping tests that can detect suzetrigine use in animals.
Objective
- To characterize the metabolic pathways of suzetrigine using liver models from horses and camels, species relevant to competitive racing contexts.
- To identify metabolites and metabolic differences between species that could inform antidoping strategies.
Methods
- In vitro metabolic experiments were conducted using:
- Equine liver microsomes (to simulate horse liver metabolism).
- Homogenized camel liver tissue (to simulate camel liver metabolism).
- Metabolic products were analyzed with:
- High-resolution liquid chromatography–high resolution mass spectrometry (LC-HRMS).
- Fragmentation analysis to assign chemical structures to metabolites based on characteristic mass spectral patterns.
Key Findings
- Seven phase I metabolites of suzetrigine (labeled M1 to M7) were identified, including modifications such as:
- Hydroxylation (adding OH groups).
- Methylation and demethylation (adding or removing methyl groups).
- Detrifluoromethylation (removal of trifluoromethyl groups).
- Cleavage of the pyridine-2-carboxamide part of the molecule.
- One phase II metabolite (M8), formed by sulfation of the demethylated metabolite M5, was found only in the camel liver model.
- Metabolite structures were tentatively assigned based on fragmentation patterns characterized by neutral losses and diagnostic ions, enabling proposals of specific biotransformations.
Comparative Metabolic Insights
- Both horse and camel liver systems shared common phase I metabolic pathways for suzetrigine.
- Camel liver exhibited additional conjugation ability (phase II sulfation) not observed in the equine system.
- These species differences are important for interpreting metabolic profiles in doping tests and might influence detection windows or metabolite targets.
Conclusions and Implications
- This study provides the first in-depth mapping of suzetrigine metabolism in two relevant animal models.
- It establishes a proposed metabolic pathway that highlights key transformations suzetrigine undergoes in liver tissue.
- Understanding these pathways can help develop sensitive, reliable antidoping tests capable of detecting suzetrigine or its metabolites in racing animals.
- The findings emphasize the importance of species-specific metabolic differences when designing testing protocols for veterinary antidoping control.
Overall Impact
- The research aids in addressing a critical gap in the detection of emerging analgesics like suzetrigine in competitive animal sports.
- It supports the advancement of safer pain management by enabling responsible use monitoring and deterrence of misuse in racing industries.
- The use of sophisticated analytical techniques demonstrates a modern approach to studying veterinary drug metabolism for antidoping science.
Cite This Article
APA
Koshy SA, Ajeebsanu MM, Karakka Kal AK, Subhahar MB, Karatt TK, Philip M.
(2025).
Mapping the Metabolic Fate of Suzetrigine in Equine and Camel Models: A Step Toward Reliable Antidoping Detection.
Rapid Commun Mass Spectrom, 40(1), e10147.
https://doi.org/10.1002/rcm.10147 Publication
Researcher Affiliations
- Equine Forensic Unit, Central Veterinary Research Laboratory, Dubai, UAE.
- Equine Forensic Unit, Central Veterinary Research Laboratory, Dubai, UAE.
- Equine Forensic Unit, Central Veterinary Research Laboratory, Dubai, UAE.
- Equine Forensic Unit, Central Veterinary Research Laboratory, Dubai, UAE.
- Equine Forensic Unit, Central Veterinary Research Laboratory, Dubai, UAE.
- Equine Forensic Unit, Central Veterinary Research Laboratory, Dubai, UAE.
MeSH Terms
- Animals
- Horses / metabolism
- Doping in Sports / prevention & control
- Microsomes, Liver / metabolism
- Camelus / metabolism
- Chromatography, Liquid
- Substance Abuse Detection / methods
- Liver / metabolism
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