New opioid medicines that target a specific receptor site to ease pain with fewer side effects

Efficacy and signaling modulation by targeting the sodium site at mu opioid receptor

NIH-funded research Washington University · NIH-11345721

This project develops opioid-like drugs aimed at easing moderate to severe chronic pain while causing fewer problems like breathing trouble and dependence.

Quick facts

Grant typeR01 grant
Study typeNIH-funded research
Funding institutionWashington University NIH-funded
Lab location1 site (Saint Louis, United States)
Project IDNIH-11345721 on NIH RePORTER

What this research studies

Researchers are designing modified fentanyl- and morphinan-based compounds that bind the mu opioid receptor in distinct ways, including at a sodium-related allosteric site. They use high-resolution cryo-EM structures to see how these molecules attach and screen chemical analogs for activation of specific G protein subtypes. Promising compounds are tested in laboratory and animal behavior experiments to look for pain relief with reduced respiratory depression and signs of dependence. The goal is to identify drug candidates that could move toward human testing if they show safer pain relief profiles.

Who could benefit from this research

Good fit: People with moderate to severe chronic pain who get inadequate relief or unacceptable side effects from current opioid medicines would be the likely candidates for future trials.

Not a fit: People needing immediate pain relief, those with pain types not responsive to opioids, or those medically ineligible for opioid therapy are unlikely to benefit from this research in the near term.

Why it matters

Potential benefit: If successful, this work could lead to pain medicines that relieve chronic pain but cause less respiratory depression and lower risk of dependence.

How similar studies have performed: Prior lab studies and some early clinical work on G protein–biased and bitopic opioid compounds have shown promise for reducing certain side effects, but clear human benefit remains uncertain.

Where this research is happening

Saint Louis, United States

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.
Last reviewed 2026-06-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.