Changes in mu opioid receptors and rheological properties of erythrocytes among opioid abusers

Evidence on the Heroin-Mediated Impairment of the Oxidative Status of Erythrocytes

Away from hemorheological properties, the effect of heroin addiction on erythrocytes is poorly investigated. This study aimed to investigate the oxidative impacts of heroin administration on erythrocytes. Study subjects included chronic intravenous heroin addicts and control subjects. Hematological analysis and redox parameters were measured, including serum concentration of methemoglobin ([MethHb]), serum glutathione peroxidase-1 ([GPX-1]), serum glutathione peroxidase (GPX) activity, erythrocytic protein carbonyl content, and oxidized to reduced glutathione (GSSG/GSH) ratio. Hematological analysis revealed that addicts had a significantly higher red cell distribution width, consistent with the mild anisocytosis and poikilocytosis of erythrocytes. As compared to control subjects, significantly higher levels of serum [Met-Hb], [GPX-1], and GPX activity ( $p<0.001$ ) were reported among addicted subjects. A significant association between [MetHb] and GPX activity was observed with r = 0.764 ( $p<0.001$ ). Furthermore, significantly higher erythrocytic protein carbonyl contents and GSSG/GSH ratio were evident among heroin addicts ( $p<0.005$ ) that were significantly associated with r = 0.429 ( $p=0.01$ ). Results demonstrate preliminary evidence that heroin addiction is implicated in impaired redox status of erythrocytes. Considering the pharmacokinetics of heroin, erythrocytic antioxidant mechanisms, and turnover rate, further investigation is required to evaluate the extent and clinical outcomes, especially upon over-dose administration.

Preoperative opiate use leads to increased postoperative opiate use and readmissions after anterior cervical discectomy and fusion

BACKGROUND

Determine effects of pre-operative opiate use on anterior cervical discectomy and fusion (ACDF) surgery outcomes.

METHODS

The study design was a single center retrospective cohort study. Patient records were reviewed from 2013 and 2018 for elective 1 to 2 level ACDF surgeries. Patients were classified as: opiate naive (ON: no history of opiate) use, acute opiate (AO: <6 months preoperatively) use, and chronic opiate (CO: 6-12 months preoperatively) use based on prescription history before surgery. Opiate use was quantified by milligram morphine equivalents (MME) at 6-12 months preop, 0-6 months preop, 0-6 months postop, and 6-12 months postop. Charts were reviewed for American Society of Anesthesiologists (ASA) physical status classification and smoking history.

RESULTS

Readmission rates were 9.8% for ON, 9.1% for AO, and 30% for CO (P value <0.05). Average opiate use measured in MME 6-12 months post-surgery was 5.76 for ON, 18.44 for AO, and 39.92 for CO (P value <0.05). Readmission rate between nonsmokers, former smokers, and active smokers was 4.4%, 0%, and 10.8% (P value <0.05) at 30-90 days post-surgery, and 1.1%, 14.5%, and 2.5% (P value <0.05) in the 91 days to 1-year post-surgery.

CONCLUSIONS

There is statistically significant relationship between CO and higher readmission rates after ACDF. Preoperative opiate use is also associated with increased opiate use 6-12 months after surgery. Smoking history is also associated with increased readmission rates.

Genome-wide association study of problematic opioid prescription use in 132,113 23andMe research participants of European ancestry

The growing prevalence of opioid use disorder (OUD) constitutes an urgent health crisis. Ample evidence indicates that risk for OUD is heritable. As a surrogate (or proxy) for OUD, we explored the genetic basis of using prescription opioids 'not as prescribed'. We hypothesized that misuse of opiates might be a heritable risk factor for OUD. To test this hypothesis, we performed a genome-wide association study (GWAS) of problematic opioid use (POU) in 23andMe research participants of European ancestry (N = 132,113; 21% cases). We identified two genome-wide significant loci (rs3791033, an intronic variant of KDM4A; rs640561, an intergenic variant near LRRIQ3). POU showed positive genetic correlations with the two largest available GWAS of OUD and opioid dependence (r_g = 0.64, 0.80, respectively). We also identified numerous additional genetic correlations with POU, including alcohol dependence (r_g = 0.74), smoking initiation (r_g = 0.63), pain relief medication intake (r_g = 0.49), major depressive disorder (r_g = 0.44), chronic pain (r_g = 0.42), insomnia (r_g = 0.39), and loneliness (r_g = 0.28). Although POU was positively genetically correlated with risk-taking (r_g = 0.38), conditioning POU on risk-taking did not substantially alter the magnitude or direction of these genetic correlations, suggesting that POU does not simply reflect a genetic tendency towards risky behavior. Lastly, we performed phenome- and lab-wide association analyses, which uncovered additional phenotypes that were associated with POU, including respiratory failure, insomnia, ischemic heart disease, and metabolic and blood-related biomarkers. We conclude that opioid misuse can be measured in population-based cohorts and provides a cost-effective complementary strategy for understanding the genetic basis of OUD.

Impact of Opioid Use in Hematological Malignancies: Clinical, Immunological and Concomitant Aspects

Opioid agents play a unique role in pain and symptom management for cancer patients. Research shows that opiate use, especially when associated with underlying cancer, has significant effects on hematological parameters. These changes may lead to greater risk for immunosuppression, tumor growth and progression of metastatic processes. The aim of this review is to explore the effects of opiates on various metabolic and biological processes, as well as the hematopoietic system, especially in cancer patients. Our findings demonstrate that the tumor-promoting effects of opiates remain contradictory, as both growth-promoting and anti-tumor effects have been observed. However, available data suggest that opiates can facilitate the proliferation and migration of tumor cells, and understanding of this process on cancer treatment is tremendously important.

Macrocytosis among patients with heroin use disorder

PURPOSE

Few empirical studies have investigated hematological parameters among people with a heroin use disorder. This study explores the prevalence of macrocytosis and associated factors among patients with heroin use disorder who were entering methadone maintenance treatment (MMT) in Taiwan.

PATIENTS AND METHODS

In this cross-sectional study, hematological parameters were measured and the prevalence of macrocytosis was assessed in a sample of 958 patients with a heroin use disorder entering the MMT program at Tsaotun Psychiatric Center in Taiwan. The demographic characteristics, heroin-related issues, other substance use history, and other clinical variables were analyzed. Univariate analysis was used to assess the association of all variables. Multivariable logistic regression was used to identify the relationship between the significant factors and macrocytosis.

RESULTS

The study found that nearly one-fifth (19.5%) of the participants had macrocytosis. Older age, longer duration of heroin use, and more days of alcohol use within the previous month were associated with macrocytosis.

CONCLUSION

We found that concurrent use of alcohol was an important factor related to macrocytosis among people with a heroin use disorder. The prevalence of macrocytosis indicated that alcohol use is common among this population. It is suggested that policies and practices regarding alcohol use should be addressed within methadone maintenance programs.

Morphine for the treatment of pain in sickle cell disease

Pain is a hallmark of sickle cell disease (SCD) and its treatment remains challenging. Opioids are the major family of analgesics that are commonly used for treating severe pain. However, these are not always effective and are associated with the liabilities of their own. The pharmacology and multiorgan side effects of opioids are rapidly emerging areas of investigation, but there remains a scarcity of clinical studies. Due to opioid-induced endothelial-, mast cell-, renal mesangial-, and epithelial-cell-specific effects and proinflammatory as well as growth influencing signaling, it is likely that when used for analgesia, opioids may have organ specific pathological effects. Experimental and clinical studies, even though extremely few, suggest that opioids may exacerbate existent organ damage and also stimulate pathologies of their own. Because of the recurrent and/or chronic use of large doses of opioids in SCD, it is critical to evaluate the role and contribution of opioids in many complications of SCD. The aim of this review is to initiate inquiry to develop strategies that may prevent the inadvertent effect of opioids on organ function in SCD, should it occur, without compromising analgesia.

The association of codeine, macrocytosis and bilateral sudden or rapidly progressive profound sensorineural deafness

CONCLUSIONS

Codeine shows a similar association with profound deafness to other opiates. Good cochlear implant outcomes suggest a sensory disorder. Although macrocytosis could be due to confounding factors, the lack of other consistent findings may signify a vascular pathology.

OBJECTIVES

To describe a series of patients identified as codeine users after referral for cochlear implantation.

PATIENTS AND METHODS

This was a retrospective case series review. Patients were identified by the senior audiologist. Information regarding mode of onset of deafness, past medical history, drug and alcohol history, investigations and audiological outcomes following cochlear implantation was collected from hospital records and patient questionnaires.

RESULTS

Ten patients were included in the study. All patients had taken codeine phosphate and paracetamol in combination for several years, usually at greater than recommended daily dose. All patients presented with sudden or rapidly progressive bilateral deafness. All patients had a significant macrocytosis at the time of deafness (mean cell volume (MCV): mean 115 fL; range 105-132 fL). No other investigation was consistently abnormal. Four patients had a history of alcoholism. Seven patients had abnormal liver function tests. Patients usually performed well with cochlear implants (CUNY sentence scores without lip reading >90% in 9 of 10 patients).

Endogenous opiates and behavior: 2002

This paper is the twenty-fifth consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over a quarter-century of research. It summarizes papers published during 2002 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).