# Impact of advanced age on opiate analgesia

> **NIH NIH R01** · GEORGIA STATE UNIVERSITY · 2021 · $359,813

## Abstract

ABSTRACT
The goal of these studies is to understand the impact of advanced age on opiate modulation of
persistent pain. In 2013, people aged 65 and older represented 14.1% of the US population. These
numbers are expected to rise dramatically, with person’s aged 65 years or older accounting for 20-
30% of the total population by 2030. Unfortunately, one of the consequences of increased longevity
is pain, with 45-85% of the population aged 65 or older experiencing pain on a daily basis.
Unfortunately, chronic pain is under-treated for the majority of elderly persons. A primary factor
contributing to the under management of pain is the dearth of knowledge on the impact of age on
pain and opiate sensitivity. Indeed, a recent consensus statement issued by a multidisciplinary
group of pain experts states: “The paucity of guidelines for opioid use in the elderly reflects the lack
of studies of these drugs on the old.” A clear understanding of age-associated changes in
opioidergic circuits of males and females is critical for evidence-based pain management in this
population. Our behavioral data indicate that the antihyperalgesic effect of morphine is significantly
attenuated in aged (18-24 mos) versus adult (2-3 mos) rats. Indeed, the ED50 dose for aged
animals is 7.0 mg/kg in comparison to 3.5 mg/kg for adults. Our overarching hypothesis is that age-
induced changes in mu opioid receptor expression and signaling within the midbrain
periaqueductal gray (PAG) provide the biological bases for the decreased sensitivity to opiates
observed in the elderly. Three specific aims are proposed to determine the influence of advanced
age on mu opioid receptor expression and receptor pharmacodynamics (SA1) and G protein
receptor coupling and regulation (SA2). Aim 3 will use molecular and pharmacological techniques
to boost central MOR signaling, thereby reducing morphine dosing requirements. Together, these
studies will provide novel and critical data on the impact of age on opiate effectiveness, and will
stimulate evidence-based therapies for the management of pain in the elderly.

## Key facts

- **NIH application ID:** 10073489
- **Project number:** 5R01DA041529-05
- **Recipient organization:** GEORGIA STATE UNIVERSITY
- **Principal Investigator:** ANNE Z MURPHY
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $359,813
- **Award type:** 5
- **Project period:** 2017-02-01 → 2022-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10073489

## Citation

> US National Institutes of Health, RePORTER application 10073489, Impact of advanced age on opiate analgesia (5R01DA041529-05). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10073489. Licensed CC0.

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