Unexpected deadly outcome of a body packer - a case of drowning and illegal drug trafficking with review

The human body is often used for illegal drug trafficking around the world. This may be done by concealing the drugs inside the body, so-called "body packing". This can lead to life-threatening conditions, mainly by leakage of the illegal substances in lethal amounts into the circulation system, which may cause fatal consequences due to acute drug overdose. Most of these cases present as sudden unexpected deaths. However, we present herein a case in which the death of an unidentified victim, which was notified as a case of seawater drowning in a non-suspicious manner, but later proved to be the death of a body packer as a result of drowning due to a morphine overdose. This case highlights the importance of investigating deaths even in unidentified bodies and the different presentations of fatal consequences of a body packer, which previously have not been described in literature.

One size does not fit all-evolution of opioid agonist treatments in a naturalistic setting over 23 years

BACKGROUND AND AIMS

Opioid agonist treatment (OAT) is currently the most effective treatment for people with opioid dependence. In most countries, however, access to the whole range of effective medications is restricted. This study aims to model the distribution of different OAT medications within a naturalistic and relatively unrestricted treatment setting (Zurich, Switzerland) over time, and to identify patient characteristics associated with each medication.

METHODS

We used generalized estimating equation analysis with data from the OAT register of Zurich and the Swiss register for heroin-assisted treatment (HAT) to model and forecast the annual proportion of opioids applying exponential distributions until 2018 and patient characteristics between 1992 and 2015.

RESULTS

Data from 11 895 patients were included in the analysis. Methadone remains the mainstay of OAT, being prescribed to two-thirds of patients. Following its approval, the proportion of HAT increased rapidly and is now constant at 12.16% [95% confidence interval (CI) = 11.15-13.17]. The initial increase of proportions of buprenorphine or slow-release oral morphine (SROM) following their approval for OAT was slower. While in 2014 both medications had a proportion of 10.2% and 10.3%, respectively, our model predicts a further increase of SROM to 19.9% in 2018, with a ceiling level of 25.19% (21.40-28.98%) thereafter. SROM patients display characteristics similar to those treated with methadone; buprenorphine patients show the highest social integration; and HAT patients are the most homogeneous group, with highest mean age, most widespread injecting experience and lowest social integration.

CONCLUSIONS

Based on data from Zurich, Switzerland from 1992 to 2015, there is no evidence for an excessive demand for a single medication in a naturalistic and liberal opioid agonist treatment setting. Rather, the specific patient characteristics associated with each medication underline the need for diversified treatment options for opioid dependence.

Morphine Binds Creatine Kinase B and Inhibits Its Activity

Morphine is an analgesic alkaloid used to relieve severe pain, and irreversible binding of morphine to specific unknown proteins has been previously observed. In the brain, changes in the expression of energy metabolism enzymes contribute to behavioral abnormalities during chronic morphine treatment. Creatine kinase B (CK-B) is a key enzyme involved in brain energy metabolism. CK-B also corresponds to the imidazoline-binding protein I₂ which binds dopamine (a precursor of morphine biosynthesis) irreversibly. Using biochemical approaches, we show that recombinant mouse CK-B possesses a μM affinity for morphine and binds to morphine in vitro. The complex formed by CK-B and morphine is resistant to detergents, reducing agents, heat treatment and SDS-polyacrylamide gel electrophoresis (SDS-PAGE). CK-B-derived peptides CK-B_1–75 and CK-B_184–258 were identified as two specific morphine binding-peptides. In vitro, morphine (1–100 μM) significantly reduces recombinant CK-B enzymatic activity. Accordingly, in vivo morphine administration (7.5 mg/kg, i.p.) to mice significantly decreased brain extract CK-B activity compared to saline-treated animals. Together, these results show that morphine strongly binds CK-B and inhibits its activity in vitro and in vivo.

The power of N-PASS, aEEG, and BIS in detecting different levels of sedation in neonates: A preliminary study

BACKGROUND

Sedatives are essential drugs in every intensive care unit in order to ensure the patient's optimal level of comfort. Avoiding conditions of over- and under-sedation is a challenge in a neonatal intensive care setting. Drug administration could be optimized by the concomitant use of objective methods to assess the level of sedation.

AIMS

We aimed to look at the ability of different methods (Neonatal Pain, Agitation and Sedation Scale, amplitude-integrated Electroencephalogram, and Bispectral Index), and their combination, in detecting different level of sedation.

METHODS

Twenty-seven neonates among whom 17 were receiving sedatives with or without opiate analgesics were monitored using the Neonatal Pain, Agitation and Sedation Scale, the amplitude-integrated Electroencephalogram, and the Bispectral Index. According to the expert opinion of two trained neonatologists, patients were categorized into three groups: no, light, and deep sedation. Four hours of simultaneous assessment of the Neonatal Pain, Agitation and Sedation Scale scores, Burdjalov scores (to summarize the amplitude-integrated Electroencephalogram trace), and Bispectral Index values were considered for the comparative analysis across these groups.

RESULTS

All three methods could differentiate patients who were not sedated from those who were deeply sedated: median score 12 and 9, respectively, (95% CI of difference = 1.99-5.99, P = 0.001) for the amplitude-integrated Electroencephalogram Burdjalov score; median 1 and -5, respectively, (95% CI of difference = 2.99-8.00, P = 0.001) for the Neonatal Pain, Agitation and Sedation Scale; and median 48 and 37, respectively, (CI of difference = 1.77-22.00, P = 0.043) for the Bispectral Index. However none of them, used alone, was able to differentiate light and deep sedation: median score 10 and 9, respectively, for the amplitude-integrated Electroencephalogram Burdjalov score; median -2 and -5, respectively, for the Neonatal Pain, Agitation and Sedation Scale; and median 48 and 37, respectively, for the Bispectral Index. Only the amplitude-integrated Electroencephalogram and the Neonatal Pain, Agitation and Sedation Scale were able to differentiate between the conditions of no sedation and light sedation. Also, according to the area under the curves values, the combination of the Neonatal Pain, Agitation and Sedation Scale with the Burdjalov score derived from the amplitude-integrated Electroencephalogram showed the best accuracy in differentiating light and deep sedation.

CONCLUSION

While none of the three methods alone was able to precisely differentiate between different levels of sedation, we suggest that using a combination of amplitude-integrated Electroencephalogram and Neonatal Pain, Agitation and Sedation Scale can be useful to distinguish between light and deep sedation in neonatal patients.

Oral Oxycodone Compared With Intravenous Morphine Sulfate for Pain Management of Isolated Limb Trauma; a Randomized Clinical Trial

INTRODUCTION

Appropriate pain relief enhances patient satisfaction and reduces patient anxiety. This study aimed to compare oral oxycodone with intravenous (IV) morphine sulfate (MS) in pain management of acute limb trauma.

METHOD

In this randomized double-blind clinical trial, patients over 14 years old, with acute isolated limb trauma were randomized to receive either 5mg IV MS or 5 mg oral oxycodone. Pain intensity and adverse effects of medications were recorded 0, 30 and 60 minutes after drug administration and compared between the groups.

RESULT

58 patients were studied. Pain intensity was similar between the two studied groups at 30 minutes (P = 0.834) and 60 minutes (P = 0.880) after drug administration. Furthermore, there was no significant difference between the two groups regarding decrease in pain within the defined time interval. Drowsiness was reported more frequently in MS group after 30 minutes (p = 0.006). Patients in MS group asked for more rescue analgesia. Other adverse effects were similar in both groups.

CONCLUSION

Oral oxycodone is as effective as IV morphine sulfate in treatment of acute musculoskeletal pain following blunt limb trauma.

Higher risk of opioid-induced respiratory depression in children with neurodevelopmental disability: a retrospective cohort study of 12 904 patients

BACKGROUND

Children with neurodevelopmental disabilities may be at risk of opioid-induced respiratory depression. We aimed to quantify the risks and effectiveness of morphine nurse-controlled analgesia (morphine-NCA) for postoperative pain in children with neurodevelopmental disabilities.

METHODS

We carried out a retrospective cohort study of 12 904 children who received postoperative i.v. morphine-NCA. Subjects were divided into a neurodevelopmental disability group and a control group. Rates of clinical satisfaction, respiratory depression, and serious adverse events were obtained, and statistical analysis, including multilevel logistic regression using Bayesian inference, was performed.

RESULTS

Of 12 904 patients, 2390 (19%) had neurodevelopmental disabilities. There were 88 instances of respiratory depression and 52 serious adverse events; there were no opioid-related deaths. The cumulative incidence of respiratory depression in the neurodevelopmental disability group was 1.09% vs 0.59% in the control group [odds ratio 1.8 (98% chance that the true odds ratio was >1)]. A significant interaction between postoperative morphine dose and neurodevelopmental disabilities was observed, with higher risk of respiratory depression with increasing dose. Satisfaction with morphine-NCA was very high overall, although children with neurodevelopmental disabilities were 1% more likely to have infusions rated as fair or poor (3.3 vs 2.1%, χ²P<0.001).

CONCLUSIONS

Children with neurodevelopmental disabilities were 1.8 times more likely to suffer respiratory depression, absolute risk difference 0.5%; opioid-induced respiratory depression in this group may relate to increased sensitivity to dose-relate respiratory effects of morphine. Morphine-NCA as described was an acceptable technique for children with and without neurodevelopmental disabilities.

Heteromerization Modulates mu Opioid Receptor Functional Properties in vivo

Mu opioid receptors modulate a large number of physiological functions. They are in particular involved in the control of pain perception and reward properties. They are also the primary molecular target of opioid drugs and mediate their beneficial analgesic effects, euphoric properties as well as negative side effects such as tolerance and physical dependence. Importantly, mu opioid receptors can physically associate with another receptor to form a novel entity called heteromer that exhibits specific ligand binding, signaling, and trafficking properties. As reviewed here, in vivo physical proximity has now been evidenced for several receptor pairs, subsequent impact of heteromerization on native mu opioid receptor signaling and trafficking identified and a link to behavioral changes established. Selective targeting of heteromers as a tool to modulate mu opioid receptor activity is therefore attracting growing interest and raises hopes for innovative therapeutic strategies.

Cyclosporin A attenuating morphine tolerance through inhibiting NO/ERK signaling pathway in human glioblastoma cell line: the involvement of calcineurin

Cyclosporin A (CsA) is known to have an immunosuppressive action. However, it is also attracting attention due to its effects on the nervous system, such as inhibiting the development and expression of morphine-induced tolerance and dependence through unknown mechanisms. It has been shown that CsA modulates the nitric oxide (NO) synthesis and extracellular signal-regulated kinases (ERK) activation, which are potentially involved in signaling pathways in morphine-induced tolerance in cellular models. Therefore, the current study was designed to evaluate the modulatory role of CsA on the MOR tolerance, by targeting the downstream signaling pathway of NO and ERK using an in vitro model. For this purpose, T98G cells were pretreated with CsA, calcineurin autoinhibitory peptide (CAIP), and N^G-nitro-l-arginine methyl ester (L-NAME) 30 min before 18 h exposure to MOR. Then, we analyzed the intracellular cyclic adenosine monophosphate (cAMP) levels and also the expression of phosphorylated ERK and nitric oxide synthase (nNOS) proteins. Our results showed that CsA (1 nM, 10 nM, and 100 nM) and CAIP (50 µM) have significantly reduced cAMP and nitrite levels as compared to MOR-treated (2.5 µM) T98G cells. This clearly revealed the attenuation of MOR tolerance by CsA. The expression of nNOS and p-ERK proteins were down-regulated when the T98G cells were pretreated with CsA (1 nM, 10 nM, and 100 nM), CAIP (50 µM), and L-NAME (0.1 mM) as compared to MOR. In conclusion, the CsA pretreatment had a modulatory role in MOR-induced tolerance, which was possibly mediated through NO/ERK signaling pathway.

Behavioral and Auditory Electrophysiological Rebound as a Compensatory Response to the Reinforcing Effects of Morphine

Auditory-evoked potentials (AEPs) can be modified by associative learning, where the appearance of learned compensatory responses (CCRs) may result in the emergence of drug withdrawal symptoms and relapse. Although CCRs' influence on later attentive and cognitive domains has been extensively examined, contextual conditioned tolerance occurring in preattentive mechanisms operating at earlier stages of information processing has remained largely unexplored. To extend our knowledge on this subject, compensatory changes on the motor and emotional aspects of behavior evoked by contextual cues were investigated with an electronic open field in morphine-pretreated rats challenged with two morphine overdoses (40 and 80 mg/kg). CCRs influence on the AEPs recorded in the central nucleus of the inferior colliculus (CIC) was analyzed with the help of a field potential recording device and a two-chamber shuttle box placed inside a Faraday cage system. The emergence of electrophysiological CCRs was analyzed by recording AEP latency and amplitude elicited in the central nucleus of the IC (CIC) with the aid of a field potential recording device and a two-chamber shuttle box placed inside a Faraday cage system. Behavioral analysis indicated that CCRs ensue in non-familiar contexts. Electrophysiological data revealed increases in the amplitude of AEPs evoked in a non-familiar context. Our results indicate that behavioral learning responses emerge following Pavlovian conditioning even with the use of low and regular doses of morphine over a short-term treatment. Changes in the CIC electrophysiology may indicate that the development of drug dependence occurs covertly in the early stages of sensory information processing.

Negligible impact of birth on renal function and drug metabolism

BACKGROUND

Transition from the intrauterine to the extrauterine environment in neonates is associated with major changes in blood flow and oxygenation with consequent increases in metabolic functions. The additional impact of birth on renal function and drug metabolism above that predicted by postmenstrual age and allometry is uncertain. Increased clearance at birth could reduce analgesic effect attributable to a lowering of plasma concentration. These elimination processes can be described using the clearance concept.

METHODS

Data from four publications that investigated the time course of glomerular filtration rate and clearance of paracetamol, morphine and tramadol were reanalyzed. The effect of birth, based on postnatal age, was used in conjunction with a theory-based allometric size scaling and maturation based on postmenstrual age.

RESULTS

Postnatal age had a short-term effect on the time course of clearance distinguishable from the well-known slower maturation based on postmenstrual age. While elimination might be relatively reduced by 15%-45% at birth, there is a rapid increase in elimination for 1-3 weeks after birth to be 15% greater than that predicted by postmenstrual age alone.

CONCLUSION

Birth is associated with a small increase in clearance in addition to that described by postmenstrual age for common analgesic drugs cleared by glucuronide conjugation (morphine, paracetamol) or by the P450 cytochrome oxidase (tramadol) and renal systems. While the increase is of biological interest, it would not be expected to have any clinically relevant impact on renal function or drug dosing. The processes of maturation described by these models are potentially applicable to any drug elimination process.

Efficacy of liposomal bupivacaine in pediatric patients undergoing spine surgery

BACKGROUND

Liposomal bupivacaine may be an option for reducing opioid utilization in pediatric scoliosis surgery. The use of liposomal bupivacaine in this patient population has not been previously described.

METHODS

Patients who underwent posterior spinal fusion surgery at our institution from 2011-2016 were identified. We performed a retrospective matched cohort study, matching patients who received intraoperative liposomal bupivacaine by age, gender, and extent of surgery to patients who did not. The primary endpoint was the use of morphine equivalents in the first 72 hours after surgery. Data collection included demographic and surgical data, pain medication utilization, and pain scores. Area under the curve (AUC) for pain scores was calculated. Descriptive statistical methods and univariable analysis were used to compare patients who received liposomal bupivacaine to patients who did not.

RESULTS

One hundred and forty-one patients met study criteria; 47 patients who received liposomal bupivacaine were matched to 94 control patients who did not receive liposomal bupivacaine. No significant differences were noted in the patient population with the patients requiring a median of 11 segments (range 10-13 segments) fused. Patients received a mean of 56.6 ± 37.4 mg/kg of intravenous acetaminophen, a mean of 3.4 ± 2.1 mg/kg of intravenous ketorolac, and 1.9 ± 0.93 mg/kg of morphine equivalents in the first 72 hours after surgery. On univariable analysis, no differences were noted in intravenous acetaminophen use, pain score AUC, intravenous ketorolac use, or morphine equivalents (2.0 ± 98 vs 1.8 ± 0.82) in patients who did not receive liposomal bupivacaine as compared to those patient who did received liposomal bupivacaine.

CONCLUSION

Liposomal bupivacaine was not associated with reductions in postoperative opioid use in pediatric spinal surgery.

Morphine reverses the effects of 1-methyl-4-phenylpyridinium in PC12 cells through activating PI3K/Akt

AIM OF THE STUDY

Parkinson's disease (PD) is a neurodegenerative disorder. It is caused by the degeneration of dopaminergic neurons and the dopamine (DA) deletion in the substantia nigra pars compacta (SNpc). Morphine elevates the level of dopamine in the mesolimbic dopamine system and plays a role in alleviating PD symptoms. However, the molecular mechanism is still unclear. The aim of the study is to investigate the mechanism on morphine alleviating PD symptoms.

MATERIALS AND METHODS

The viability of PC12 cells was measured by using MTT assay. The expressions of tyrosine hydroxylase (TH), thioredoxin-1 (Trx-1), CyclinD1 and Cyclin-dependent kinase5 (Cdk5) were detected by Western Blot.

RESULTS

In present study, we found that morphine increased the cell viability in PC12 cells. 1-methyl-4-phenylpyridi-nium (MPP+) reduced the cell viability and TH expression, which were reversed by morphine. MPP+ decreased the expressions of Trx-1, CyclinD1, Cdk5, which were restored by morphine. Moreover, the role of morphine in restoring the expressions of Trx-1, CyclinD1 and Cdk5 decreased by MPP+ was abolished by LY294002, phosphatidylinositol-3-kinase (PI3K)/Akt inhibitor.

CONCLUSIONS

These results suggest that morphine reverses effects induced by MPP þ through activating PI3K/Akt pathway.

Practical management of opioid rotation and equianalgesia

Purpose

To review the recent literature on opioid rotation (ie, switching from one opioid drug to another or changing an opioid’s administration route) in cancer patients experiencing severe pain and to develop a novel equianalgesia table for use in routine clinical practice.

Methods

The MEDLINE database was searched with terms “cancer pain,” “opioid rotation,” “opioid switching,” “opioid ratio,” “opioid conversion ratio,” and “opioid equianalgesia” for the major opioids (morphine, oxycodone, fentanyl, and hydromorphone) and the intravenous, subcutaneous, oral, and transdermal administration routes. Selected articles were assessed for the calculated or cited opioid dose ratio, bidirectionality, and use of the oral morphine equivalent daily dose or a direct drug-to-drug ratio.

Results

Twenty publications met our selection criteria and were analyzed in detail. We did not find any large-scale, prospective, double-blind randomized controlled trial with robust design, and most of the studies assessed relatively small numbers of patients. Bidirectionality was investigated in seven studies only.

Conclusion

The updated equianalgesic table presented here incorporates the latest data and provides information on bidirectionality. Despite the daily use of equianalgesic tables, they are not based on high-level scientific evidence. More clinical research is needed on this topic.

Irinotecan Alters the Disposition of Morphine Via Inhibition of Organic Cation Transporter 1 (OCT1) and 2 (OCT2)

PURPOSE

The organic cation transporters (OCTs) and multidrug and toxin extrusions (MATEs) together are regarded as an organic cation transport system critical to the disposition and response of many organic cationic drugs. Patient response to the analgesic morphine, a characterized substrate for human OCT1, is highly variable. This study was aimed to examine whether there is any organic cation transporter-mediated drug and drug interaction (DDI) between morphine and commonly co-administrated drugs.

METHODS

The uptake of morphine and its inhibition by six drugs which are commonly co-administered with morphine in the clinic were assessed in human embryonic kidney 293 (HEK293) cells stably expressing OCT1, OCT2 and MATE1. The in vivo interaction between morphine and the select irinotecan was determined by comparing the disposition of morphine in the absence versus presence of irinotecan treatment in mice.

RESULTS

The uptake of morphine in the stable HEK293 cells expressing human OCT1 and OCT2 was significantly increased by 3.56 and 3.04 fold, respectively, than that in the control cells, with no significant uptake increase in the cells expressing human MATE1. All of the six drugs examined, including amitriptyline, fluoxetine, imipramine, irinotecan, ondansetron, and verapamil, were inhibitors of OCT1/2-mediated morphine uptake. The select irinotecan significantly increased the plasma concentrations and decreased hepatic and renal accumulation of morphine in mice.

CONCLUSIONS

Morphine is a substrate of OCT1 and OCT2. Clinician should be aware that the disposition of and thus the response to morphine may be altered by co-administration of an OCT1/2 inhibitor, such as irinotecan.

Wnt7a in Mouse Insular Cortex Contributes to Anxiety-like Behavior During Protracted Abstinence from Morphine

Anxiety is considered an important protracted abstinence symptom that can aggravate craving and relapse risk in opioid addicts. Although the insular cortex (IC) has been reported to be a key brain region in mediating emotional and motivational alterations induced by drug consumption and withdrawal, the role of IC in anxiety related to protracted abstinence remains elusive. In this study, we found that: (1) anxiety-like behavior in morphine-dependent mice became significant after 28 days of withdrawal, while their physical symptoms became undetectable. (2) Activated glutamatergic neurons in the medial IC, but not the anterior or posterior IC were significantly increased after 28 days of withdrawal. Bilateral lesion of the medial IC, but not the anterior or posterior IC with ibotenic acid (IBO) alleviated the anxiety-like behavior. (3) Expression of Wnt7a in the medial IC was significantly increased after 28 days of withdrawal, and specific down-regulation of Wnt7a with AAV-shWnt7a also alleviated the anxiety-like behavior. The findings reveal the medial IC is involved in mediating anxiety-like behavior related to morphine protracted abstinence, in which Wnt7a plays a critical role.

Venlafaxine Attenuates the Development of Morphine Tolerance and Dependence: Role of L-Arginine/Nitric Oxide/cGMP Pathway

BACKGROUND

Severe pain reduces quality of life of patients with various diseases, often because chronic morphine therapy results in reduced analgesic effectiveness, or tolerance, leading to escalating doses and distressing adverse effects. Nitric oxide (NO) plays a role in morphine tolerance and dependence.

OBJECTIVE

Venlafaxine, an antidepressant, is known to modulate nitric oxide (NO) pathway in nervous tissues. In the present study, the effect of systemic venlafaxine (VLF) on the development of morphine tolerance and dependence, acute morphine-induced antinociception, and the probable involvement of the L-arginine/NO/cGMP pathway in these effects were investigated in mice.

METHODS

Animals developed tolerance to the antinociceptive effect of morphine (50 mg/kg, s.c. daily) for 3 consecutive days. NO modulators like L-NAME (NO synthase inhibitor) and L-Arginine (L-Arg, substrate for NO synthase), sildenafil (cGMP-PDE inhibitor) alone or in combination with venlafaxine were used.

RESULTS

The results showed that i.p. administration of VLF (5-40 mg/kg) produced antinociceptive effect in a dose-dependent way. Pretreatment with L-Arg (200 mg/kg, i.p.) reversed the antinociception and L-NAME (30 mg/kg, i.p.) and sildenafil (10 mg/kg, i.p.) potentiated the antinociceptive effect. Moreover, co-administration of VLF in non-effective dose (5 mg/kg) with morphine, potentiated acute morphine-induced analgesia (5 mg/kg, s.c.). This effect was antagonized by L-arginine (200 mg/kg, i.p.) and potentiated by L-NAME (30 mg/kg, i.p.) and sildenafil (10 mg/kg, i.p.). On the other hand, VLF was prevented the development of morphine antinociceptive tolerance and dependence. These effects were antagonized by L-arginine (200 mg/kg, i.p.) and potentiated by L-NAME (30 mg/kg, i.p.) and sildenafil (10 mg/kg, i.p.).

CONCLUSION

Our data suggest that the combination of VLF with morphine may be a relevant therapeutic implication to manage pain even when tolerance to morphine exists. Moreover, our data demonstrates the involvement of L-Arg/NO/cGMP pathway in the prevention of morphine tolerance and dependence by venlafaxine.

Opioid Deaths: Trends, Biomarkers, and Potential Drug Interactions Revealed by Decision Tree Analyses

Opioid abuse is now the primary cause of accidental deaths in the United States. Studies over several decades established the cyclical nature of abused drugs of choice, with a current resurgence of heroin abuse and, more recently, fentanyl’s emergence as a major precipitant of drug-related deaths. To better understand abuse trends and to explore the potential lethality of specific drug–drug interactions, we conducted statistical analyses of forensic toxicological data from the Wayne County Medical Examiner’s Office from 2012–2016. We observed clear changes in opioid abuse over this period, including the rapid emergence of fentanyl and its analogs as highly significant causes of lethality starting in 2014. We then used Chi-square Automatic Interaction Detector (CHAID)-based decision tree analyses to obtain insights regarding specific drugs, drug combinations, and biomarkers in blood most predictive of cause of death or circumstances surrounding death. The presence of the non-opioid drug acetaminophen was highly predictive of drug-related deaths, likely reflecting the abuse of various combined acetaminophen-opioid formulations. The short-lived cocaine adulterant levamisole was highly predictive of a short post-cocaine survival time preceding sudden non-drug-related death. The combination of the opioid methadone and the antidepressant citalopram was uniformly linked to drug death, suggesting a potential drug–drug interaction at the level of a pathophysiological effect on the heart and/or drug metabolism. The presence of fentanyl plus the benzodiazepine midazolam was diagnostic for in-hospital deaths following serious medical illness and interventions that included these drugs. These data highlight the power of decision tree analyses not only in the determination of cause of death, but also as a key surveillance tool to inform drug abuse treatment and public health policies for combating the opioid crisis.

DARK Classics in Chemical Neuroscience: Opium, a Historical Perspective

Opium is the latex from the opium poppy Papaver somniferum L., which humankind has utilized since ancient Mesopotamia all the way to modern times. Opium used to be surrounded in divine mystery or magic-like abilities and was given to cure a wide variety of diseases until its analgesic, antitussive, and antidiarrheal properties were understood, the resulting alkaloids were isolated, and their structure and properties unmasked. Opium went from being sold in any store front in the form of pills or tinctures with no prescription necessary for purchase or smoked in an opium den down the street, to then bringing about consumer advocacy and the right to know what is in a medication. Legislation was created to limit the prescribing and selling of medications to doctors and pharmacists as well as outlawing opium dens and smoking opium. This review focuses primarily on the uses of opium throughout history, the isolation of the principle alkaloids, and their structure elucidation.

Exploring Morphine-Triggered PKC-Targets and Their Interaction with Signaling Pathways Leading to Pain via TrkA

It is well accepted that treatment of chronic pain with morphine leads to μ opioid receptor (MOR) desensitization and the development of morphine tolerance. MOR activation by the selective peptide agonist, D-Ala2, N-MePhe4, Gly-ol]-enkephalin(DAMGO), leads to robust G protein receptor kinase activation, β-arrestin recruitment, and subsequent receptor endocytosis, which does not occur in an activation by morphine. However, MOR activation by morphine induces receptor desensitization, in a Protein kinase C (PKC) dependent manner. PKC inhibitors have been reported to decrease receptor desensitization, reduce opiate tolerance, and increase analgesia. However, the exact role of PKC in these processes is not clearly delineated. The difficulties in establishing a particular role for PKC have been, in part, due to the lack of reagents that allow the selective identification of PKC targets. Recently, we generated a conformation state-specific anti-PKC antibody that preferentially recognizes the active state of this kinase. Using this antibody to selectively isolate PKC substrates and a proteomics strategy to establish the identity of the proteins, we examined the effect of morphine treatment on the PKC targets. We found an enhanced interaction of a number of proteins with active PKC, in the presence of morphine. In this article, we discuss the role of these proteins in PKC-mediated MOR desensitization and analgesia. In addition, we posit a role for some of these proteins in mediating pain by TrKA activation, via the activation of transient receptor potential cation channel subfamily V member 1 (TRPV1). Finally, we discuss how these new PKC interacting proteins and pathways could be targeted for the treatment of pain.

Morphine Attenuates fNIRS Signal Associated With Painful Stimuli in the Medial Frontopolar Cortex (medial BA 10)

Functional near infrared spectroscopy (fNIRS) is a non-invasive optical imaging method that provides continuous measure of cortical brain functions. One application has been its use in the evaluation of pain. Previous studies have delineated a deoxygenation process associated with pain in the medial anterior prefrontal region, more specifically, the medial Brodmann Area 10 (BA 10). Such response to painful stimuli has been consistently observed in awake, sedated and anesthetized patients. In this study, we administered oral morphine (15 mg) or placebo to 14 healthy male volunteers with no history of pain or opioid abuse in a crossover double blind design, and performed fNIRS scans prior to and after the administration to assess the effect of morphine on the medial BA 10 pain signal. Morphine is the gold standard for inhibiting nociceptive processing, most well described for brain effects on sensory and emotional regions including the insula, the somatosensory cortex (the primary somatosensory cortex, S1, and the secondary somatosensory cortex, S2), and the anterior cingulate cortex (ACC). Our results showed an attenuation effect of morphine on the fNIRS-measured pain signal in the medial BA 10, as well as in the contralateral S1 (although observed in a smaller number of subjects). Notably, the extent of signal attenuation corresponded with the temporal profile of the reported plasma concentration for the drug. No clear attenuation by morphine on the medial BA 10 response to innocuous stimuli was observed. These results provide further evidence for the role of medial BA 10 in the processing of pain, and also suggest that fNIRS may be used as an objective measure of drug-brain profiles independent of subjective reports.

Extended-Release Morphine for Chronic Breathlessness in Pulmonary Arterial Hypertension-A Randomized, Double-Blind, Placebo-Controlled, Crossover Study

CONTEXT

Pulmonary arterial hypertension (PAH) affects people of all ages and is associated with poor prognosis. Chronic breathlessness affects almost all people with PAH.

OBJECTIVES

This randomized, placebo-controlled, double-blind, crossover study aimed to evaluate the effects of regular, low-dose, extended-release (ER) morphine for PAH-associated chronic breathlessness.

METHODS

Participants with PAH-associated chronic breathlessness were randomized to 1) seven days of ER morphine 20 mg, 2) seven-day washout, and 3) seven days of identically looking placebo, or vice versa. Primary end points were breathlessness "right now"-morning and evening-measured with a Visual Analogue Scale. Secondary end points included additional breathlessness measures, quality of life, function, harms, and blinded treatment preference (ACTRN12609000209291).

RESULTS

Within a period of seven years, 50 patients were assessed in detail and 23 (46%) were randomized (despite broad eligibility criteria). Four participants withdrew while taking morphine. Nineteen participants completed the study. Breathlessness "right now" was higher on morphine compared with placebo both for morning [mean (M) ± SD 31.7 ± 25 mm vs. 26.9 ± 22 mm; effect size (80% CI) = -0.22 (-0.6 to 0.2)] and evening [(M ± SD 33.5 ± 28 mm vs. 25.6 ± 21 mm; effect size (80% CI) = -0.33 (-0.8 to 0.1)]. All secondary measures of breathlessness were higher with morphine as were nausea and constipation.

CONCLUSION

This study does not support a Phase III study of ER morphine for people with PAH-associated chronic breathlessness. Recruiting to the target sample size was difficult, the direction of effect in every measure of breathlessness favored placebo and morphine generated more harms.

Astrocyte EV-Induced lincRNA-Cox2 Regulates Microglial Phagocytosis: Implications for Morphine-Mediated Neurodegeneration

Impairment of microglial functions, such as phagocytosis and/or dysregulation of immune responses, has been implicated as an underlying factor involved in the pathogenesis of various neurodegenerative disorders. Our previous studies have demonstrated that long intergenic noncoding RNA (lincRNA)-Cox2 expression is influenced by nuclear factor κB (NF-κB) signaling and serves as a coactivator of transcriptional factors to regulate the expression of a vast array of immune-related genes in microglia. Extracellular vesicles (EVs) have been recognized as primary facilitators of cell-to-cell communication and cellular regulation. Herein, we show that EVs derived from astrocytes exposed to morphine can be taken up by microglial endosomes, leading, in turn, to activation of Toll-like receptor 7 (TLR7) with a subsequent upregulation of lincRNA-Cox2 expression, ultimately resulting in impaired microglial phagocytosis. This was further validated in vivo, wherein inhibition of microglial phagocytic activity was also observed in brain slices isolated from morphine-administrated mice compared with control mice. Additionally, we also showed that intranasal delivery of EVs containing lincRNA-Cox2 siRNA (small interfering RNA) was able to restore microglial phagocytic activity in mice administered morphine. These findings have ramifications for the development of EV-loaded RNA-based therapeutics for the treatment of various disorders involving functional impairment of microglia.

Sinomenine Protects Against Morphine Dependence through the NMDAR1/CAMKII/CREB Pathway: A Possible Role of Astrocyte-Derived Exosomes

Sinomenine is a nonaddictive alkaloid used to prevent morphine dependence, even thoughits mechanism isnot fully understood. Astrocytes aggravate the pathological process in their neighboring cellsthrough exosomes in central nervous system diseases. However, the effect of sinomenine on astrocyte-derived exosomes for the amelioration of morphine dependence has not been reported yet. In this study, we found that sinomenine prevented the morphine-induced conditionedplace preference in mice. Sinomenine reduced the levels of cAMP and intracellular Ca2+ in morphine-treated SH-SY5Y cells. Moreover, sinomenine inhibited the expressions of p-NMDAR1/NMDAR1, p-CAMKII/CAMKII, and p-CREB/CREB in the hippocampusof morphine-dependent mice and SH-SY5Y cells. Furthermore, we found that sinomenine inhibitedthe morphine-induced activation of astrocytesin vivo and in vitro. Afterwards, exosomes were isolated from cultured primary astrocytes treated with phosphate buffer saline (PBS, ctl-exo), morphine (mor-exo), or morphine and sinomenine (Sino-exo). Subsequently, morphine-treated SH-SY5Y cells were treated with ctl-exo, mor-exo, and Sino-exo. Results showed that Sino-exo reduced the level of cAMP, intracellular Ca2+, and the expression of p-CAMKII/CAMKII and p-CREB/CREB in morphine-treated SH-SY5Y cells. In conclusion, we demonstrated that sinomenine exhibited protective effects against morphine dependencein vivo and in vitro through theNMDAR1/CAMKII/CREB pathway. Sinomenine-induced alterationof the function of astrocyte-derived exosomes may contribute to the antidependence effects of sinomenine in morphine dependence.

Combining Brain Microdialysis and Translational Pharmacokinetic Modeling to Predict Drug Concentrations in Pediatric Severe Traumatic Brain Injury: The Next Step Toward Evidence-Based Pharmacotherapy?

Evidence-based analgosedation in severe pediatric traumatic brain injury (pTBI) management is lacking, and improved pharmacological understanding is needed. This starts with increased knowledge of factors controlling the pharmacokinetics (PK) of unbound drug at the target site (brain) and related drug effect(s). This prospective, descriptive study tested a pediatric physiology-based pharmacokinetic software model by comparing actual plasma and brain extracellular fluid (brain_ECF) morphine concentrations with predicted concentration-time profiles in severe pTBI patients (Glasgow Coma Scale [GCS], ≤8). Plasma and brain_ECF samples were obtained after legal guardian written consent and were collected from 8 pTBI patients (75% male; median age, 96 months [34.0-155.5]; median weight, 24 kg [14.5-55.0]) with a need for intracranial pressure monitoring (GCS, ≤8) and receiving continuous morphine infusion (10-40 μg/kg/h). Brain_ECF samples were obtained by microdialysis. Brain_ECF samples were taken from "injured" and "uninjured" regions as determined by microdialysis catheter location on computed head tomography. A previously developed physiology-based software model to predict morphine concentrations in the brain was adapted to children using pediatric physiological properties. The model predicted plasma morphine concentrations well for individual patients (97% of data points within the 90% prediction interval). In addition, predicted brain_ECF concentration-time profiles fell within a 90% prediction interval of microdialysis brain_ECF drug concentrations when sampled from an uninjured area. Prediction was less accurate in injured areas. This approach of translational physiology-based PK modeling allows prediction of morphine concentration-time profiles in uninjured brain of individual patients and opens promising avenues towards evidence-based pharmacotherapies in pTBI.

Minocycline increases firing rates of accumbal neurons and modifies the effects of morphine on neuronal activity

Accumulating evidence indicated that minocycline, a glial cell modulator, is able to modify a variety of morphine effects. Here, we investigated minocycline effects on electrical activity of nucleus accumbens (NAc) neurons using single unit recording in urethane-anesthetized rats. In addition, we investigated whether minocycline can modify the effects of morphine on NAc neural activity during reinstatement of morphine-seeking behavior. Minocycline increased the NAc firing activity in intact animals. Electrophysiological recording in morphine-treated animals was performed, following the acquisition of morphine-induced conditioned place preference (5 mg/kg, s.c., 3 days) and a drug-free extinction period. In acutely minocycline- treated animals, the neurons were recorded for 40 minutes following a single injection of either minocycline (50 μg/5 μl, i.c.v.) or saline. Then a priming dose of morphine (1 mg/kg, s.c.) was injected while the recording was continued for an additional 40 minutes. Minocycline significantly increased the firing rates of neurons and significantly modified morphine inhibitory effects on NAc neurons. In subchronically minocycline-treated groups, the rats were given daily injections of minocycline (50 μg/5 μl, i.c.v) during the extinction period. Then, on the reinstatement day, NAc neurons were recorded for 10 minutes, the priming dose of morphine was administered and the recording was continued for 45 minutes. Our results showed the failure of minocycline to significantly modify the inhibitory effects of morphine. In conclusion, our findings indicated that minocycline modifies morphine-induced decreases in the firing rates of NAc neurons in the reinstatement phase.