Opioids and Immunosuppression: Clinical Evidence, Mechanisms of Action, and Potential Therapies

Background

In addition to the more well-known adverse effects of opioids, such as constipation, mounting evidence supports underlying immunosuppressive effects as well.

Methods

In this study, we provide a narrative review of preclinical and clinical evidence of opioid suppression of the immune system as well as possible considerations for therapies.

Results

In vitro and animal studies have shown clear effects of opioids on inflammatory cytokine expression, immune cell activity, and pathogen susceptibility. Observational data in humans have so far supported preclinical findings, with multiple reports of increased rates of infections in various settings of opioid use. However, the extent to which this risk is due to the impact of opioids on the immune system compared with other risk factors associated with opioid use remains uncertain. Considering the data showing immunosuppression and increased risk of infection with opioid use, measures are needed to mitigate this risk in patients who require ongoing treatment with opioids. In preclinical studies, administration of opioid receptor antagonists blocked the immunomodulatory effects of opioids.

Conclusions

As selective antagonists of peripheral opioid receptors, peripherally acting mu-opioid receptor (MOR) antagonists may be able to protect against immune impairment while still allowing for opioid analgesia. Future research is warranted to further investigate the relationship between opioids and infection risk as well as the potential application of peripherally acting MOR antagonists to counteract these risks.

Opioid usage after left ventricular assist device implantation: A single center retrospective analysis

BACKGROUND

Opioid use disorder is a known national concern and extends across multiple populations; however, opioid use in the left ventricular assist device (LVAD) population and subsequent outcomes is not well described.

OBJECTIVES

We sought to understand opioid use and patient characteristics among the LVAD population at a single center and associated outcomes after index LVAD hospitalization in relation to opioid use.

METHODS

A single center retrospective review of pre-operative and post-operative opioid use was characterized during the index admission for LVAD implantation. Additionally, we reviewed medical records from patients with opioid prescription at hospital discharge stratified by oral morphine equivalents (OME) and refills of opioid prescriptions with analysis of the outcomes of readmission and death after hospital discharge from the index admission for LVAD implantation.

RESULTS

Opioid exposed patients in this cohort increased in frequency from 0% of patients in 2007 to a peak of 25.9% of patients in 2013, and gradually declined thereafter to 12.5% in 2017.

CONCLUSIONS

Despite the rate of high dose opioid therapy in this cohort, neither opioid use, opioid history, oral morphine equivalents (OME), or opioid refills portended worse survival after LVAD implantation.