# Multifunctional Opioid/CCK Ligands for Pain and Addiction

> **NIH NIH P01** · UNIVERSITY OF ARIZONA · 2021 · $159,733

## Abstract

SUMMARY (Project B): 
Opiates are medically appropriate for the treatment of acute (nociceptive) or cancer pain. It is not known, 
however, whether these drugs provide long-term benefit in chronic non-malignant (e.g., neuropathic) pain. 
Some studies suggest an overall decrease in quality of life of patients receiving opiates for chronic pain. 
Additionally, opiates can produce physical dependence, and promote addiction, drug abuse and death due to 
overdose. Eric Holder, Attorney General of the United States, recently stated “right now, few substances are 
more lethal than prescription opiates and heroin” (NY Times, March 10, 2014). There is a high unmet medical 
need for the discovery of treatments that allow management of chronic non-malignant pain, that sustain 
efficacy for extended periods while maintaining quality of life and that diminish the possibility of addiction and 
abuse. 
In this sub-project (Project B), and consistent with the overall aims of the Program Project grant, we consider 
the adaptive changes that occur in the brain as a consequence of chronic pain, and from the opiates 
themselves, in the design of novel therapies. Preclinical research has demonstrated that experimental 
neuropathic pain, or sustained exposure to opiates such as morphine, produces upregulation of 
cholecystokinin (CCK) in descending pain modulation circuits as well as in reward/motivation circuits. CCK 
elicits both pro-nociceptive and anti-opioid actions. Together these neural adaptations diminish the analgesic 
actions of opiates so that more drug is needed to elicit the same effect on pain (i.e., tolerance). Higher doses 
of drugs are associated with increased side-effects and increased likelihood of addiction and abuse. CCK 
produces hyperalgesia in animals and is associated with the nocebo response in humans. 
Blockade of CCK receptors (a) enhances opiate potency and promotes sustained efficacy in experimental 
chronic non-malignant pain; (b) diminishes opiate-induced sedation and gastrointestinal slowing, common side- 
effects that decrease quality of life with chronic use; (c) decreases the naloxone-precipitated withdrawal 
syndrome in morphine-dependent rats; and (d) decreases morphine-induced dopamine release in the reward 
pathway. Thus, blockade of CCK receptors could allow for improved opiate-mediated control of chronic non- 
malignant pain while maintaining quality of life. Additionally, CCK receptor blockade could diminish opiate 
dependence, as well as addiction and possibly drug craving providing benefits both to individuals and society. 
We hypothesize that we can discover a single small molecular weight, non-peptidic molecule with high affinity 
CCK antagonist and mu opioid agonist activity. We additionally hypothesize that such orally availability and 
CNS penetrant molecules will show enhanced and sustained activity in chronic pain, as well as reduced liability 
for dependence, addiction and craving. Such compounds with dual functio...

## Key facts

- **NIH application ID:** 10151591
- **Project number:** 5P01DA041307-05
- **Recipient organization:** UNIVERSITY OF ARIZONA
- **Principal Investigator:** Frank Porreca
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $159,733
- **Award type:** 5
- **Project period:** 2017-05-01 → 2024-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10151591

## Citation

> US National Institutes of Health, RePORTER application 10151591, Multifunctional Opioid/CCK Ligands for Pain and Addiction (5P01DA041307-05). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10151591. Licensed CC0.

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