Oxycodone/naloxone prolonged-release tablets in patients with moderate-to-severe, chronic cancer pain: Challenges in the context of hepatic impairment

Clinically significant drug-drug interactions involving opioid analgesics used for pain treatment in patients with cancer: update of a systematic review

INTRODUCTION

Drug-drug interactions (DDIs) are among factors that may affect the efficacy and safety of opioid treatment. Data on clinically manifested DDIs are scarse, and recommendations that might guide physicians are presently lacking. The aim of this study was to update a systematic review (2015) on studies reporting clinically significant DDIs involving opioids used for pain treatment in adult patients with cancer.

METHODS

Systematic literature searches in MEDLINE, Embase, and Cochrane Central Register of Controlled Trials from the start of the databases through 18 September 2023.

RESULTS

Of the 1968 retrieved papers, 16 were included in the final analysis, together with five papers identified through hand-searching of reference lists. Nineteen publications were case reports or case series. Nine, sixteen, and eight patients presented adverse effects from opioids, impaired pain control, or opioid withdrawal, respectively. The main mechanisms underlying DDIs were alteration of cytochrome P450 3A4 activity and pharmacodynamic antagonism resulting from concurrent use of an opioid analgesic and a peripheral mu-opioid receptor antagonist (PAMORA).

CONCLUSION

Knowledge about clinically significant DDIs associated with opioids in cancer patients is currently mostly based upon case reports. These cases give information about drug combinations that should be recognized as potentially harmful by physicians prescribing opioids.

PROSPERO ID

CRD42023481103.

A Randomized, Double-Blind, Placebo-Controlled Trial Protocol Using the Fuzhengxiaoliu Patch for the Management of Primary Liver Cancer Pain

Objective

Chronic pain strongly affects the quality of life of patients with liver cancer pain. Safe and effective management of cancer-related pain is a worldwide challenge. Traditional Chinese medicine (TCM) has rich clinical experience in the treatment of cancer pain. The Fuzhengxiaoliu patch (FZXLP) is a compound TCM with the effects of detoxification and pain relief and has shown great efficacy in the treatment of patients with liver cancer, but high-quality clinical research that provides research-based evidence is lacking. We designed a randomized, double-blind, placebo-controlled trial to explore and evaluate the efficacy of FZXLP for the treatment of liver cancer pain.

Methods

This is a prospective, randomized, double-blind, placebo-controlled trial. The trial will enrol 72 participants with primary liver cancer with cancer pain (damp-heat stagnation and toxin and blood stasis syndrome). The primary objective is to measure the reduction in pain using FZXLP in combination with tegafur, gimeracil and oteracil potassium capsule (S-1) compared to the placebo group with S-1. Pain will be measured by the number of opioids used, Chinese versions of the numerical rating scale (NRS), pain relief rate and number of breakthrough cases of cancer pain (BTcP). The secondary objectives include response evaluation criteria in solid tumors (RECIST), tumor markers, TCM syndrome scores, weight, functional assessment of cancer therapy-hepatobiliary (FACT-Hep) questionnaire scores, and self-rating anxiety scale scores. Adverse events (AEs) will be recorded throughout the study.

Discussion

This study integrated TCM with clinical research to assess the efficacy and safety of the addition of FZXLP in the treatment of primary liver cancer pain.

Trial registration

Chinese clinical trial registry, ChiCTR2300076951, Registered on October 25, 2023. https://www.chictr.org.cn/showproj.html?proj=209608.

Managing Severe Cancer Pain with Oxycodone/Naloxone Treatment: A Literature Review Update

Severe cancer pain substantially affects patients' quality of life, increasing the burden of the disease and reducing the disability-adjusted life years. Although opioid analgesics are effective, they may induce opioid-induced bowel dysfunction (OIBD). Oxycodone/naloxone combination therapy has emerged as a promising approach to mitigate opioid-induced constipation (OIC) while providing effective pain relief. This review provides an updated analysis of the literature of the last decade regarding the use of oxycodone/naloxone in the management of severe cancer pain. Through a comprehensive search of databases, studies focusing on the efficacy, safety, and patient experience of oxycodone/naloxone's prolonged release in severe cancer pain management were identified. Furthermore, the literature discusses the mechanism of action of naloxone in mitigating OIC without compromising opioid analgesia. Overall, the evidence suggests that oxycodone/naloxone combination therapy offers a valuable option for effectively managing severe cancer pain while minimizing opioid-induced constipation, thereby improving patients' quality of life. However, further research is needed to optimize dosing regimens, evaluate long-term safety, and assess patient outcomes in diverse cancer populations.

Opioid toxicity after oxycodone/naloxone to oxycodone conversion: case series

Combination preparations of oxycodone/naloxone are marketed to aid in the management of opioid induced bowel dysfunction, with caution advised in prescribing in cases of liver dysfunction.This case series demonstrates four cases of patients with normal liver function tests who developed significant opioid toxicity on conversion from combination oxycodone/naloxone to oxycodone at equivalent doses, necessitating significant dose reduction.In each case, a cause for intra-hepatic shunting such as cirrhosis, porto-systemic collaterals or thrombosis were identified, highlighting these as cautionary features when prescribing combination preparations of oxycodone/naloxone and the possible need for dose reduction if converting to oxycodone.

No pain, no strain: Targin® mitigates pain and constipation following spinal cord injury

BACKGROUND

Opioids effectively reduce chronic pain, but present significant side effects including opioid-induced constipation. Oxycodone/naloxone decreases pain and constipation in cancer patients, however its effect on spinal cord injury population remains understudied.

METHODS

We assessed whether oxycodone/naloxone reduces pain, constipation, and severity of autonomic dysreflexia in an individual with spinal cord injury. A 55-year-old male with C5 lesion presented with chief complaint of chronic pain received 5/2.5 mg and 20/10 mg oxycodone/naloxone for 6 and 2 weeks, respectively.

RESULTS

Oxycodone/naloxone improved pain, bowel function, and autonomic dysreflexia severity.

INTERPRETATION

Oxycodone/naloxone was effective in managing chronic pain and constipation in the studied case.

Rostral Anterior Cingulate Cortex–Ventrolateral Periaqueductal Gray Circuit Underlies Electroacupuncture to Alleviate Hyperalgesia but Not Anxiety-Like Behaviors in Mice With Spared Nerve Injury

Neuropathic pain is a common cause of chronic pain and is often accompanied by negative emotions, making it complex and difficult to treat. However, the neural circuit mechanisms underlying these symptoms remain unclear. Herein, we present a novel pathway associated with comorbid chronic pain and anxiety. Using chemogenetic methods, we found that activation of glutamatergic projections from the rostral anterior cingulate cortex (rACC^Glu) to the ventrolateral periaqueductal gray (vlPAG) induced both hyperalgesia and anxiety-like behaviors in sham mice. Inhibition of the rACC^Glu-vlPAG pathway reduced anxiety-like behaviors and hyperalgesia in the spared nerve injury (SNI) mice model; moreover, electroacupuncture (EA) effectively alleviated these symptoms. Investigation of the related mechanisms revealed that the chemogenetic activation of the rACC^Glu-vlPAG circuit effectively blocked the analgesic effect of EA in the SNI mice model but did not affect the chronic pain-induced negative emotions. This study revealed a novel pathway, the rACC^Glu-vlPAG pathway, that mediates neuropathic pain and pain-induced anxiety.