# Examining Novel Fentalogs: Pharmacological Characteristics and Reversibility

> **NIH NIH R03** · UNIVERSITY OF MICHIGAN AT ANN ARBOR · 2020 · $78,000

## Abstract

Opioid analgesics, such as morphine and hydrocodone, are widely used for the treatment
of moderate to severe pain but are also widely misused and abused. Opioid-related
overdoses account for almost half of all drug overdose deaths in the United States and
cause more preventable deaths every year than car crashes. Fentanyl, a highly potent
mu opioid receptor (MOR) agonist, and its analogues (fentalogs) are increasingly found
in drug samples from search and seizure by law enforcement and are thought to
contribute to the drastic increase in opioid-induced overdose deaths since 2016. In fact,
the number of deaths and drug seizures involving fentalogs is likely an underestimate, as
the rapid rate at which new fentalogs are synthesized makes it difficult for law
enforcement and forensic specialists to keep up. As many of these compounds are novel
analogs, very little is known about their basic pharmacology in terms of receptor affinity
or activity at the opioid receptors. The objective of this proposal is to evaluate novel
fentalogs, many of which have been identified in illicit samples, in terms of binding affinity
and receptor function at the three classical opioid receptors: MOR, the delta opioid
receptor (DOR), and the kappa opioid receptor (KOR). This will be accomplished using
standard competitive radioactive ligand binding and G protein turnover assays. The ability
of a standard rescue therapy, naloxone (trade name Evzio or Narcan), to reverse the
agonist activity of the most potent and efficacious fentalogs will also be examined; real
time cAMP accumulation will be used to determine agonist function and reversal by
antagonists, such as naloxone. The overarching hypothesis is that many of these novel
fentalogs are more potent and efficacious than traditional opioid agonists and that
standard treatments for opioid overdose may be insufficient when fentalogs are involved.
Overall, this project will characterize the in vitro pharmacological properties of novel
fentalogs found in street drugs and has the potential to inform best practices for
preventing opioid overdose and related deaths.

## Key facts

- **NIH application ID:** 9901497
- **Project number:** 5R03DA048129-02
- **Recipient organization:** UNIVERSITY OF MICHIGAN AT ANN ARBOR
- **Principal Investigator:** Jessica Priya Anand
- **Activity code:** R03 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $78,000
- **Award type:** 5
- **Project period:** 2019-04-01 → 2021-09-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9901497

## Citation

> US National Institutes of Health, RePORTER application 9901497, Examining Novel Fentalogs: Pharmacological Characteristics and Reversibility (5R03DA048129-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9901497. Licensed CC0.

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