Self-treatment of opioid withdrawal using kratom (Mitragynia speciosa korth)

The Police Opioid Seizure Temporal Risk (POSTeR) model of increased exposure to fatal overdose

CONTEXT

Police seizures of illicit opioids remain a dominant strategy for addressing problematic substance use and overdose in the United States and throughout the world, yet qualitative accounts and quantitative analyses exhibit positive associations between police opioid seizures and ensuing risk of fatal overdose at the local level of individual incidents. Since these associations run counter to the commonly held belief that removing potent illicit substances from the community is protective of overdose, a causal model is needed to demonstrate this association and convey the overdose risks that follow from police opioid seizures.

METHODS

Leveraging well-established biological and psychological outcomes of opioid use disorder and opioid supply interruption, our analysis presents the Police Opioid Seizure Temporal Risk (POSTeR) Model, an individual-level casual model that begins at the point of opioid dependence, introduces an interruption to an individual's supply of opioids as the result of a police drug seizure, and presents the physical and behavioral outcomes that increase the ensuing temporal risk of fatal overdose.

RESULTS

The aftermath of a police opioid seizure can increase a person's risk of fatal overdose. The urgent need to prevent or reduce acute opioid withdrawal symptoms leads people to seek a replacement supply, while reduced opioid tolerance resulting from post-seizure involuntary abstinence combines with the uncertain potency of a replacement supply of illicit opioids to significantly increase the difficulty of administering a safe but effective dose. In the face of these hazards, people in withdrawal often have a reduced aversion to risk, prompting them to consume this uncertain dose in a manner that increases their exposure to overdose.

CONCLUSIONS

Strategies that emphasize police opioid seizures as an acceptable way to reduce the prevalence of illicit drugs in a community without accounting for the elevated risk of fatal overdose that results can worsen one of the most significant problems they are meant to address.

Kratom Alkaloids, Cannabinoids, and Chronic Pain: Basis of Potential Utility and Role in Therapy

Introduction: Chronic neuropathic pain is as a severe detriment to overall quality of life for millions of Americans. Current pharmacological treatment options for chronic neuropathic pain are generally limited in efficacy and may pose serious adverse effects such as risk of abuse, nausea, dizziness, and cardiovascular events. Therefore, many individuals have resorted to methods of pharmacological self-treatment. This narrative review summarizes the existing literature on the utilization of two novel approaches for the treatment of chronic pain, cannabinoid constituents of Cannabis sativa and alkaloid constituents of Mitragyna speciosa (kratom), and speculates on the potential therapeutic benefits of co-administration of these two classes of compounds. Methods: We conducted a narrative review summarizing the primary motivations for use of both kratom and cannabis products based on epidemiological data and summarize the pre-clinical evidence supporting the application of both kratom alkaloids and cannabinoids for the treatment of chronic pain. Data collection was performed using the PubMed electronic database. The following word combinations were used: kratom and cannabis, kratom and pain, cannabis and pain, kratom and chronic pain, and cannabis and chronic pain. Results: Epidemiological evidence reports that the self-treatment of pain is a primary motivator for use of both kratom and cannabinoid products among adult Americans. Further evidence shows that use of cannabinoid products may precede kratom use, and that a subset of individuals concurrently uses both kratom and cannabinoid products. Despite its growing popularity as a form of self-treatment of pain, there remains an immense gap in knowledge of the therapeutic efficacy of kratom alkaloids for chronic pain in comparison to that of cannabis-based products, with only three pre-clinical studies having been conducted to date. Conclusion: There is sufficient epidemiological evidence to suggest that both kratom and cannabis products are used to self-treat pain, and that some individuals actively use both drugs, which may produce potential additive or synergistic therapeutic benefits that have not yet been characterized. Given the lack of pre-clinical investigation into the potential therapeutic benefits of kratom alkaloids against forms of chronic pain, further research is warranted to better understand its application as a treatment alternative.

Exploring the cognitive effects of kratom: A review

Despite the strict kratom regulation in some regions, the demand for kratom products is still increasing worldwide. Kratom products are commonly consumed for their pain-relieving effect or as a self-treatment for opioid use disorder. Kratom is also taken as a recreational drug among youth and adults. Since substance abuse can cause cognitive impairment, many studies investigated the effects of kratom on cognition. The interaction of some kratom alkaloids with various receptors such as opioid, serotonergic, and adrenergic receptors further sparks the interest to investigate the effects of kratom on cognitive function. Hence, this review aims to provide an overview of the effects of kratom on cognitive behaviours and their underlying changes in neurobiological mechanisms. In conclusion, kratom, particularly its main alkaloid, mitragynine may adversely affect cognitive performances that may be attributed to the disruption in synaptic plasticity, brain activity as well as various proteins involved in synaptic transmission. The impact of kratom on cognitive functions could also shed light on its safety profile, which is essential for the therapeutic development of kratom, including its potential use in opioid substitution therapy.

Effects of kratom alkaloids on mesolimbic dopamine release

Kratom is derived from the leaves of a plant (Mitragyna speciosa) native to Southeast Asia that has been consumed for its complex stimulant-like effects at low doses, opiate-like effects at high doses, to treat mood related issues like anxiety or depression, or to help ameliorate opioid withdrawal symptoms. However, the neural mechanisms of its major psychoactive alkaloids, mitragynine (MG) and 7-hydroxymitragynine (7-HMG), are still not clear. Given that the effects of kratom are often compared to drugs with abuse liabilities, the current study examined the effects of MG and 7-HMG on reward-related neurotransmission. Fixed potential amperometry was used to quantify stimulation-evoked phasic dopamine release in the nucleus accumbens (NAc) of anesthetized male and female mice before and after MG (1, 15, or 30 mg/kg i.p.), 7-HMG (0.5, 1, or 2 mg/kg i.p.), or vehicle. MG reduced dopamine release over the recording period (90 min) in a dose dependent manner, and the low dose of MG significantly increased dopamine autoreceptor functioning in males. Both sexes responded similarly to 7-HMG with the low dose of 7-HMG increasing dopamine release while the high dose decreased dopamine release. 7-HMG did not alter dopamine autoreceptor functioning for either sex. Neither MG nor 7-HMG altered the clearance rate of stimulation-evoked dopamine. Findings suggest that these kratom alkaloids do alter dopamine functioning, although potentially not in a way consistent with classic drugs of abuse. Further investigation of the neural mechanisms of kratom's alkaloids will provide crucial and urgent insight into their therapeutic uses or potential abuse liability.

The regulatory effects of mitragynine on P-glycoprotein transporter

OBJECTIVES

Kratom preparation containing Mitragyna speciosa Korth plant is frequently used as a recreational drug. Mitragynine, a major alkaloid isolated from M. speciosa, is often detected concurrently with other drugs during forensic analysis, indicating a safety concern. P-glycoprotein (P-gp) is a multidrug transporter. Modulation of P-gp transport activity by drugs or herbal compounds in the brain may lead to drug-herb interactions, resulting in neurotoxicity. We aim to determine the effects of mitragynine on the P-gp regulation and possible neurotoxicity.

METHODS

The effects of mitragynine on the P-gp regulation were investigated in human brain capillary endothelial cells (hCMEC/D3) using molecular docking and dynamic simulation and an optimized bidirectional transport assay, respectively. Repeated-dose treatment and neurotoxicity assessment were carried out using a blood-brain barrier model and polimerase chain reaction (PCR) array.

KEY FINDINGS

Mitragynine inhibits the P-gp transport activity via binding onto the nucleotide-binding domain site and forms a stable interaction with the P-gp protein complex. Nontoxic concentrations of mitragynine (<4 μM) and substrate drugs (0.001 μM) in the cells significantly enhanced endothelial cell permeability and elicited signs of neurotoxicity in PC-12 cells.

CONCLUSIONS

Mitragynine is likely a P-gp inhibitor, hence concurrent administration of kratom products with P-gp substrates may lead to clinically significant interactions and neurotoxicity.

The neuropharmacology of kratom, a novel psychoactive natural product

Kratom (Mitragyna speciosa, Korth.) is a tropical tree that is indigenous to Southeast Asia. When ingested, kratom leaves or decoctions from the leaves have been reported to produce complex stimulant and opioid-like effects. For generations native populations in Southeast Asia have used kratom products to stave off fatigue, improve mood, alleviate pain and manage symptoms of opioid withdrawal. Over the past 15-20 years, kratom use has spread to Western nations including the United States, where many individuals are using kratom products for the self-management of pain, opioid use disorder, anxiety and depression. The increased use of kratom has triggered a surge in research into the biochemistry, pharmacology and behavioral effects of kratom and its active constituents, especially mitragynine and 7-hydroxymitragynine. In this review, we highlight some of the recent animal studies showing that kratom and its constituent compounds have potential beneficial effects in animal models of pain, anxiety, depression and opioid dependence. We also highlight studies showing that kratom can modulate the functioning of opioid, noradrenergic, serotonergic and dopaminergic systems. The highlighted studies strongly suggest that kratom and its constituents may form the basis for the development of novel therapeutic agents.

Kratom (Mitragyna speciosa) use for self-management of pain: Insights from cross-sectional and ecological momentary assessment data

Kratom (Mitragyna speciosa) is increasingly used in the US for self-management of pain, despite limited research on its efficacy and safety. To better understand how and why people use kratom for pain self-management, we analyzed baseline survey data (N = 395) and 15-day ecological momentary assessment (EMA) data (N = 357) from kratom consumers across the US. Although we recruited participants based on their kratom use, not on whether they used it for pain management, nearly half (49.1 %) met criteria for chronic pain, with many reporting substantial pain relief and high effectiveness of kratom in managing pain. A majority (69.2 %) reported difficulties in obtaining adequate pain treatment, and most indicated that these challenges impacted their decision to try kratom. Most participants did not report concerns about overuse or significant side effects. EMA data showed that, regardless of chronic-pain status, pain relief was the most frequently endorsed primary motivation for daily kratom use. There were no significant association between daily pain levels and kratom use frequency, and no difference in the daily kratom use between those with vs. without chronic pain. Recent kratom use was associated with lower current pain levels. Stronger subjective effects of kratom were associated with lower pain levels. This effect was significantly moderated by chronic-pain status: those with chronic pain showed a stronger link between subjective kratom effects and pain reduction. These findings underscore the urgent need for systematic, rigorous research on long-term implications, efficacy, and safety of kratom in pain management to guide informed clinical practices and regulatory policies. PERSPECTIVE: This study reveals that chronic pain is common among kratom consumers, who frequently use it for pain self-management and report significant relief, as shown by ecological momentary assessment. There is an urgent need for research into kratom's safety, efficacy, and mechanisms to guide clinical practice and inform policies.

Mitragyna speciosa Korth toxicity: Experimental findings and future prospects

Mitragyna speciosa (Roxb.) Korth, locally known as kratom, is a traditional medicinal plant from Southeast Asia, with mitragynine as its principal alkaloid. Similar to other medicinal plants, kratom has side effects and toxicities, which have been documented in scientific studies and case reports. The mitragynine sale and possession of kratom are prohibited in Malaysia but legalized in Thailand. In the US, kratom is not lawfully marketed as a drug product, a dietary supplement, or a food additive in conventional food. Despite these restrictions, individuals continue to self-administer kratom to alleviate various health problems, often without a comprehensive understanding of the associated toxicities. Hence, the primary aim of this review is to provide a comprehensive overview of the toxicities associated with kratom, drawing from scientific studies, case reports, and other relevant sources. It also addresses the management of these toxicities, identifies gaps in existing studies, and discusses future perspectives. Therefore, a literature review search was conducted to gather essential information for this review. The in vitro studies focused on metabolizing enzymes, indirectly indicating kratom toxicity. By contrast, the in vivo results directly demonstrated kratom's toxic effects on the liver, kidneys, lungs, and brain. Case studies, primarily from Western countries, involved both single and combination use of kratom. Thus, by shedding light on these aspects, we aim to enhance awareness among healthcare professionals and the general public. Additionally, identifying existing gaps can guide future scientific studies. Since prevention is better than cure, this review holistically presents information about the toxicities associated with the use of kratom leaves, serving anyone seeking to understand and prevent kratom-related toxicities.

Aggression in a Cohort of Male Methamphetamine (METH) Users With and Without Kratom (Mitragyna speciosa Korth.) Use History in Malaysia

Methamphetamine (METH) consumption is associated with aggression. Decoction derived from the kratom (Mitragyna speciosa Korth.) leaf has been used as a METH substitute in Southeast Asia. Given its perceived benefit, we investigated the relationship between kratom use and aggression in a treatment sample of METH users with and without kratom use history. Four hundred and three male METH users participated in this cross-sectional study. A semi-structured questionnaire and several objective clinical measures were administered. Results indicate that there were no significant differences in aggression and its dimensions between METH users with and without kratom use history. However, two distinct Clusters (1 and 2) of METH users with kratom use history were studied. Users in Cluster 1 were characterized by a higher quantity and frequency of daily kratom use, longer duration of kratom use, and use of kratom at a younger age. Users in Cluster 2 exhibited the opposite characteristics. Kratom dependence and the first age of kratom use were identified as risk factors for aggression in Cluster 1. The frequency of daily kratom use appeared as a protective factor against aggression in Cluster 2. The results offer partial support to the instrumental kratom use concept; lower frequency (1 to 3 times) of kratom use may potentially minimize aggression in METH users presenting with mild to moderate kratom dependence.

Kratom: A Narrative Review of the Possible Clinical Uses and Dangers of This Opioid-Like Plant

The term "kratom" refers to a plant species formally known as Mitragyna speciosa. Kratom is composed of over 40 alkaloids, a type of organic compound that contains nitrogen. These compounds work primarily via binding to opioid receptors expressed on neurons, where they stimulate signal transduction mechanisms involving the activation of G proteins. Kratom has been shown to cause both a stimulant-like effect and a sedative effect in humans. These studies have shown that use is highest among European-American, middle-class men living in suburban areas. Additionally, individuals who have a history of opioid misuse are also more likely to take kratom. Kratom is used by many different people in the US for numerous different reasons. Some of the most often cited reasons include treating chronic pain conditions, depression, and anxiety. Individuals who used kratom for these reasons typically consumed kratom daily at a dose of 1-3 grams, with the kratom extracted into a powder to be consumed in a capsule. Additionally, there have been reports of kratom being used to treat opioid withdrawal symptoms, as kratom can bind to some of the same receptors as opioids. This manuscript specifically describes trends regarding the use of kratom in the US, pharmacokinetic and pharmacodynamic properties of kratom, potential therapeutic uses of kratom, adverse events caused by kratom, and case studies in the literature regarding patients using kratom.

The Mitragyna speciosa (kratom) alkaloid mitragynine: Analysis of adrenergic α2 receptor activity in vitro and in vivo

Mitragynine, an alkaloid present in the leaves of Mitragyna speciosa (kratom), has a complex pharmacology that includes low efficacy agonism at μ-opioid receptors (MORs). This study examined the activity of mitragynine at adrenergic α2 receptors (Aα2Rs) in vitro and in vivo. Mitragynine displaced a radiolabeled Aα2R antagonist ([3H]RX821002) from human Aα2ARs in vitro with lower affinity (Ki = 1260 nM) than the agonists (-)-epinephrine (Ki = 263 nM) or lofexidine (Ki = 7.42 nM). Mitragynine did not significantly stimulate [35S]GTPγS binding at Aα2ARs in vitro, but in rats trained to discriminate 32 mg/kg mitragynine from vehicle (intraperitoneally administered; i.p.), mitragynine exerted an Aα2R agonist-like effect. Both α2R antagonists (atipamezole and yohimbine) and MOR antagonists (naloxone and naltrexone) produced rightward shifts in mitragynine discrimination dose-effect function and Aα2R agonists lofexidine and clonidine produced leftward shifts. In the mitragynine trained rats, Aα2R agonists also produced leftward shifts in discrimination dose-effect functions for morphine and fentanyl. In a separate rat cohort trained to discriminate 3.2 mg/kg i.p. morphine from vehicle, naltrexone produced a rightward shift, but neither an Aα2R agonist or antagonist affected morphine discrimination. In a hypothermia assay, both lofexidine and clonidine produced marked effects antagonized by yohimbine. Mitragynine did not produce hypothermia. Together, these data demonstrate that mitragynine acts in vivo like an Aα2R agonist, although its failure to induce hypothermia or stimulate [35S]GTPγS binding in vitro, suggests that mitragynine maybe a low efficacy Aα2R agonist.

Chemical, pharmacological properties and biosynthesis of opioid mitragynine in Mitragyna speciosa (kratom)

Mitragynine, an alkaloid found in Mitragyna speciosa (kratom), shows promise as a potential alternative to opioids owing to its distinctive indole alkaloid structure and its capacity for pain relief, alleviation of opioid withdrawal symptoms, and anti-inflammatory effects. Recently the intricate process of mitragynine biosynthesis from the precursor strictosidine was elucidated, providing insights into the complex pathways responsible for synthesizing this opioid compound and its related diastereomers. As the search continues for the authentic hydroxylase and methyltransferase crucial for mitragynine formation, leveraging enzymes from other species and exploiting enzyme promiscuity has facilitated heterologous mitragynine biosynthesis in microbes. This highlights the extraordinary flexibility of enzymes in generating a spectrum of variations and analogs of kratom opioids within alternative biological systems.

Kratom: a primer for pain physicians

PURPOSE OF REVIEW

Kratom is used commonly in the United States, usually to mitigate pain, opioid withdrawal, or fatigue. A comprehensive discussion on kratom, tailored to pain management physicians, is needed, given its associated risks and potential interactions.

RECENT FINDINGS

Kratom and its main metabolites, mitragynine and 7-OH-mitragynine, bind to a variety of receptors including mu opioid receptors. Still, kratom cannot be described as a classic opioid. Kratom has been utilized without FDA approval as an alternative to traditional medications for opioid use disorder and opioid withdrawal. Lower doses of kratom typically cause opioid-like effects while higher doses can have sedating effects. Tolerance, dependence and withdrawal still occur, although kratom withdrawal appears to be more moderate than opioid withdrawal. Contamination with heavy metals and biological toxins is concerning and there is potential for serious complications, including seizures and death.

SUMMARY

The use of kratom as an opioid-sparing alternative as a part of a multimodal pain regimen is not without significant risks. It is of utmost importance for pain physicians to be aware of the risks and adverse effects associated with kratom use.

Acquired Type 1 Brugada Syndrome Induced by Chronic High-Dose Kratom Use

Kratom denotes the naturally occurring alkaloids found in Mitragyna speciosa and is self-administered for the treatment of chronic pain, anxiety, and opioid withdrawal. Kratom is cardiotoxic with several case reports linking its use to QTc prolongation and ventricular dysrhythmias; however, there exist few reports of kratom-induced Brugada syndrome. A 36-year-old male with a past medical history inclusive of polysubstance abuse, bipolar disorder, and seizure disorder presented to the emergency department for chest pain. The patient reported a three-week history of lightheadedness when standing, oftentimes accompanied by palpitations and syncope. The patient was prescribed lamotrigine but reported non-adherence for more than three months due to a lack of insurance. The patient self-administered high-dose (~100 grams/day) white vein kratom daily for the last three years for symptoms of opioid withdrawal and alcohol cravings. He denied a family history of sudden cardiac death. The initial electrocardiogram (EKG) demonstrated coved ST segments followed by a negative T wave in leads V1 and V2 consistent with a type 1 Brugada pattern. Pacer pads were applied, and cardiology and electrophysiology were consulted. The patient was admitted to the medical intensive care unit on telemetry. Serial EKGs returned to normal sinus rhythm, and an inpatient flecainide challenge was negative, making Brugada syndrome secondary to chronic high-dose kratom use the most likely diagnosis. We presented a case of type 1 Brugada syndrome induced by chronic high-dose kratom use. While the clinical management of kratom toxicity is mostly supportive, physicians should consider potentially fatal cardiac dysrhythmias including Brugada syndrome.

Beneficial and adverse health effects of kratom (Mitragyna speciosa): A critical review of the literature

Used in Southeast Asia for generations, kratom gained popularity in the United States and elsewhere over the past several decades. Derived from Mitragyna speciosa, kratom preparations including leaves, teas, powders, capsules, and extracts may yield stimulant, analgesic, and opioid-like effects that occur dose-dependently based on concentrations of kratom's key alkaloids, mitragynine and 7-hydroxymitragynine. Such effects are responsible for kratom's potential as a reduced-harm alternative to opiates and as a withdrawal treatment. But these properties are also associated with tolerance development and addictive potential. Given mitragynine and 7-hydroxymitragynine activity on cytochrome P450 isoforms and opioid receptors, adverse effects among polysubstance users are a concern. Current literature on the toxicology of kratom is reviewed, including product alkaloid concentrations, in vitro and in vivo data, epidemiological evidence, and human case data. The potential harms and benefits of kratom products are discussed within an exposure assessment framework, and recommendations for industry are presented. Current evidence indicates that kratom may have therapeutic potential in some persons and that products present few risks with typical, non-polysubstance use. However, few studies identified alkaloid doses at which adverse effects were expected in humans or animals. Such research is needed to inform future assessments of kratom's risks and benefits.

Treatment of poppy seed tea misuse with buprenorphine in a telehealth practice: a case series

BACKGROUND

Poppy seed tea (PST) is a legally obtainable source of opiates made from the seeds of the opium poppy. Our large telehealth opioid use disorder (OUD) provider group has treated several patients with PST misuse.

METHODS

We retrospectively identified patients with primary PST use disorder treated with buprenorphine in a telehealth-only practice with first visits between January 2021 and December 2022. Patients were identified by having the word "poppy" in their enrollment note, and then charts were reviewed to determine which patients had primary PST misuse. Demographics, buprenorphine doses, and retention in treatment were recorded.

RESULTS

We identified 18 patients treated for PST use disorder. Fifteen (83.3%) identified as male, mean age was 40.4 (standard deviation 8.8) years, and patients resided in 10 different U.S. states. Median starting buprenorphine dose was 2 mg (interquartile range (IQR) 2-2.5 mg). Median stabilizing dose of buprenorphine was 16 mg daily (IQR 15-20.5 mg). As of June 2023, 5 patients (27.8%) were still in active treatment. Two patients (11.1%) had completed a planned, elective taper. Ten patients (55.6%) had unplanned discontinuation from treatment, and 3 patients (16.7%) discontinued for other reasons.

CONCLUSIONS

To our knowledge, this is the largest case series describing PST misuse in the U.S., and the first to demonstrate its treatment in the telehealth setting. PST use disorder is treatable with buprenorphine with doses similar to treatment of other opioid use disorders. Clinicians who treat patients with OUD should be aware of PST use disorder and its treatment.

Isolated Kratom Use Disorder Treated With Extended-Release Buprenorphine Taper

ABSTRACT

This case report highlights a 36-year-old male without history of psychiatric disease, chronic pain, or substance use disorder who developed severe substance use disorder per Diagnostic and Statistical Manual of Mental Disorders , Fifth Edition criteria to kratom. He was successfully treated with sublingual buprenorphine after a 3-year period of intermittent withdrawal management and trials of oral and extended-release injectable naltrexone. After a period of abstinence from kratom, he was tapered from buprenorphine using 2 monthly injections of 100 mg extended-release buprenorphine. His case underscores some of the current uncertainties around kratom use disorder diagnosis and treatment.

Controversies in Assessment, Diagnosis, and Treatment of Kratom Use Disorder

PURPOSE OF REVIEW

We apply the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5) criteria for substance use disorders (SUDs) to the herbal product kratom. Similarities and differences between kratom use disorder (KUD) and other SUDs are explored, along with assessment, diagnostic, and therapeutic recommendations for KUD.

RECENT FINDINGS

Literature reports of "kratom addiction" or KUD rarely specify the criteria by which patients were diagnosed. Individuals meeting DSM-5 KUD criteria typically do so via tolerance and withdrawal, using more than intended, and craving, not functional or ​psychosocial disruption, which occur rarely. Most clinicians who use medication to treat patients with isolated KUD select buprenorphine formulations, although there are no controlled studies showing that buprenorphine is safe or efficacious in this patient population. Diagnosis and treatment decisions for KUD should be systematic. We propose an algorithm that takes into consideration whether KUD occurs with comorbid opioid use disorder.

[Kratom-From natural remedy to addictive drug and back]

BACKGROUND

Kratom/ketum is a psychoactive herbal preparation that has been used for a long time as a remedy and performance-enhancing substance in Southeast Asia. The advancement of globalization is making kratom increasingly more available in the western world, where it is becoming increasingly more used.

OBJECTIVE

The current research on kratom and its ingredients is presented.

MATERIAL AND METHODS

An overview of the use and effects of kratom is exemplary given on the basis of reports. The instrumentalization of the drug and its consequences up to the development of addiction are discussed.

RESULTS

Consumption is accompanied by several instrumentalizeable effects so that kratom is used as a therapeutic substance in the self-management of pain, anxiety and depression as well as other substance addictions. Another benefit comes from the performance-enhancing effects on physical work and in a social context. Consumption is usually well controlled, rarely escalates and has few and mostly mild aversive side effects. The danger arises from consumption particularly when there is an escalation of the dose and from mixed consumption with other psychoactive substances. The main alkaloid mitragynine and the more potent 7‑hydroxy-mitragynine are considered mainly responsible for the effect. Both have a complex pharmacology that involves partial µ‑opioid receptor agonism.

DISCUSSION

Epidemiological, clinical and neurochemical studies have shown that kratom only has a limited addictive drug profile, which might suggest a medical use as a remedy or substitute in addiction treatment.

Associations Between Opioid and Kratom Use in the USA: Differences by Race/Ethnicity and Sexual Orientation

BACKGROUND

Kratom is federally unregulated and is marketed as an opioid alternative despite limited evidence and known negative effects. Disparities in associations between opioid and kratom use may be partly attributed to race/ethnicity and sexual orientation given differences in marketing, use motives, and prescriber practices.

METHODS

Data: 2021 nationally representative National Survey on Drug Use and Health among individuals aged 18 + . We used weighted logistic regression analyses to assess race/ethnicity and sexual orientation as moderators of associations between past-year opioid (1) use (total sample, n = 44,877) and (2) misuse and use disorder (among those with past-year opioid use, n = 10,398) and the outcome of kratom use (lifetime, past year).

RESULTS

26.76% reported past-year opioid use, and among those, 12.20% and 7.54% reported past-year opioid misuse and use disorder, respectively; 1.72% and 0.67% had lifetime and past-year kratom use, respectively. Opioid use was positively associated with lifetime (aOR = 2.69, 95%CI = 1.98, 3.66) and past-year (aOR = 3.84, 95%CI = 2.50, 5.92) kratom use; associations among non-Hispanic Black and Hispanic (vs. non-Hispanic White) participants were weaker (p < 0.01). Among participants reporting past-year opioid use, misuse and use disorder were positively associated with lifetime (aORmisuse = 2.46, 95%CI = 1.60, 3.78; aORuse disorder = 5.58, 95%CI = 2.82, 11.04) and past-year (aORmisuse = 2.40, 95%CI = 1.26, 4.59; aORuse disorder = 3.08, 95%CI = 1.48, 6.41) kratom use; among bisexual (vs. heterosexual) participants, opioid use disorder was associated with a lower probability of lifetime kratom use (p < 0.01).

DISCUSSION

We observed positive associations between opioid and kratom use, with potential disparities among certain racial/ethnic and sexual orientation groups. Research should examine the mechanisms contributing to these differences to inform prevention and intervention efforts.

Multimodal Image Fusion Workflow Incorporating MALDI Imaging Mass Spectrometry and Microscopy for the Study of Small Pharmaceutical Compounds

Multimodal imaging analyses of dosed tissue samples can provide more comprehensive insights into the effects of a therapeutically active compound on a target tissue compared to single-modal imaging. For example, simultaneous spatial mapping of pharmaceutical compounds and endogenous macromolecule receptors is difficult to achieve in a single imaging experiment. Herein, we present a multimodal workflow combining imaging mass spectrometry with immunohistochemistry (IHC) fluorescence imaging and brightfield microscopy imaging. Imaging mass spectrometry enables direct mapping of pharmaceutical compounds and metabolites, IHC fluorescence imaging can visualize large proteins, and brightfield microscopy imaging provides tissue morphology information. Single-cell resolution images are generally difficult to acquire using imaging mass spectrometry but are readily acquired with IHC fluorescence and brightfield microscopy imaging. Spatial sharpening of mass spectrometry images would thus allow for higher fidelity coregistration with other higher-resolution microscopy images. Imaging mass spectrometry spatial resolution can be predicted to a finer value via a computational image fusion workflow, which models the relationship between the intensity values in the mass spectrometry image and the features of a high-spatial resolution microscopy image. As a proof of concept, our multimodal workflow was applied to brain tissue extracted from a Sprague-Dawley rat dosed with a kratom alkaloid, corynantheidine. Four candidate mathematical models, including linear regression, partial least-squares regression, random forest regression, and two-dimensional convolutional neural network (2-D CNN), were tested. The random forest and 2-D CNN models most accurately predicted the intensity values at each pixel as well as the overall patterns of the mass spectrometry images, while also providing the best spatial resolution enhancements. Herein, image fusion enabled predicted mass spectrometry images of corynantheidine, GABA, and glutamine to approximately 2.5 μm spatial resolutions, a significant improvement compared to the original images acquired at 25 μm spatial resolution. The predicted mass spectrometry images were then coregistered with an H&E image and IHC fluorescence image of the μ-opioid receptor to assess colocalization of corynantheidine with brain cells. Our study also provides insights into the different evaluation parameters to consider when utilizing image fusion for biological applications.

Mitragynine (Kratom)-Withdrawal behaviour and cognitive impairments can be ameliorated by an epigenetic mechanism

BACKGROUND AND PURPOSE

Kratom is a preparation from Mitragyna speciosa, which is used as a natural drug preparation for many purposes around the world. However, an overdose of Kratom may cause addiction-like problems including aversive withdrawal states resulting in cognitive impairments via unknown mechanisms. Its main psychoactive alkaloid is mitragynine, showing opioid-like properties.

EXPERIMENTAL APPROACH

Here, we analysed the neuropharmacological effects of mitragynine compared with morphine withdrawal in rats and searched for a pharmacological treatment option that may reverse the occurring cognitive deficits that usually aggravate withdrawal.

KEY RESULTS

We found that withdrawal from 14-day mitragynine (1-10 mg·kg-1·day-1) treatment caused dose-dependent behavioural withdrawal signs resembling those of morphine (5 mg·kg-1·day-1) withdrawal. However, mitragynine (5 and 10 mg·kg-1·day-1) withdrawal also induced impairments in a passive avoidance task. Mitragynine withdrawal not only reduced hippocampal field excitatory postsynaptic potential (fEPSP) amplitudes in basal synaptic transmission and long-term potentiation (LTP) but also reduced epigenetic markers, such as histone H3K9 and H4K12 expression. At the same time, it up-regulates HDAC2 expression. Targeting the epigenetic adaptations with the HDAC inhibitor, SAHA, reversed the effects of mitragynine withdrawal on epigenetic dysregulation, hippocampal input/output curves, paired-pulse facilitation, LTP and attenuated the cognitive deficit. However, SAHA amplified the effects of morphine withdrawal.

CONCLUSION AND IMPLICATIONS

The data from this work show that changes in histone expression and downstream hippocampal plasticity may explain mitragynine, but not morphine, withdrawal behaviours and cognitive impairments. Thus, it may provide a new treatment approach for aversive Kratom/mitragynine withdrawal and addiction.

Formation of multiple ion types during MALDI imaging mass spectrometry analysis of Mitragyna speciosa alkaloids in dosed rat brain tissue

Mitragyna speciosa, more commonly known as kratom, has emerged as an alternative to treat chronic pain and addiction. However, the alkaloid components of kratom, which are the major contributors to kratom's pharmaceutical properties, have not yet been fully investigated. In this study, matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry was used to map the biodistribution of three alkaloids (corynantheidine, mitragynine, and speciogynine) in rat brain tissues. The alkaloids produced three main ion types during MALDI analysis: [M + H]+, [M - H]+, and [M - 3H]+. Contrary to previous reports suggesting that the [M - H]+ and [M - 3H]+ ion types form during laser ablation, these ion types can also be produced during the MALDI matrix application process. Several strategies are proposed to accurately map the biodistribution of the alkaloids. Due to differences in the relative abundances of the ions in different biological regions of the tissue, differences in ionization efficiencies of the ions, and potential overlap of the [M - H]+ and [M - 3H]+ ion types with endogenous metabolites of the same empirical formula, a matrix that mainly produces the [M + H]+ ion type is optimal for accurate mapping of the alkaloids. Alternatively, the most abundant ion type can be mapped or the intensities of all ion types can be summed together to generate a composite image. The accuracy of each of these approaches is explored and validated.

The prevalence of kratom use and association with co-occurring substance use among adolescents: a 2022 Bangkok behavioral surveillance survey, Thailand

Thailand removed kratom from the list of prohibited substances in 2021, possession and consumption of Kratom is now legal. It is prohibited from selling Kratom to anyone under the age of 18 and/or who is pregnant or breastfeeding. While there are benefits from kratom use with few reported adverse effects, escalating dose and increased use frequency raise the risk for toxic events in the setting of polysubstance use or development of a use disorder. We utilized data from the Behavior Surveillance Survey in Bangkok (n = 5,740) to examine the use of kratom with other substances use in the 12 months before the survey. The prevalence of past-year kratom use among students was 9.3% (95%CI = 8.7-9.9), with higher proportions of males (12.4 versus 6.1%, p < 0.001). The factors associated with past 12-month kratom use were academic performance (Medium GPA; AOR = 2.41, 95% CI = 1.76-3.29; Low GPA; AOR = 4.15, 95% CI = 2.94-5.87), close friend use substance (AOR = 1.94, 95% CI = 1.44-2.59), cannabis use (AOR = 6.84, 95% CI = 4.61-10.15), consumed alcohol (AOR = 2.32, 95% CI = 1.77-3.02), smoked conventional cigarettes (AOR = 4.20, 95% CI = 3.16-5.58), used e-cigarettes (AOR = 4.37, 95% CI = 3.30-5.79) used illicit opioids (AOR = 8.13, 95% CI = 4.35-15.18), and other illicit drug use (AOR = 9.15, 95% CI = 3.78-22.14). These findings may be useful for the initial targeting of efforts to reduce adolescent consumption of kratom. Future studies should examine the effect of regulatory policies or other Thai FDA-related policies use of illicit drugs and e-cigarettes on kratom use.

The Complexities of Kratom: Insights on an Increasingly Frequent Clinical Encounter

Mitragyna speciosa (kratom) is a tropical tree native to Southeast Asia with dose-dependent stimulant and opioid properties. Kratom has garnered attention due to its increasing popularity and potential for dependence, tolerance, and withdrawal. We report the case of a 72-year-old man admitted to the hospital for a deep vein thrombosis and obstructive uropathy who began experiencing kratom withdrawal. He experienced less cravings and improvement in withdrawal symptoms with buprenorphine-naloxone 8 mg/2 mg daily. Notably, our case highlights kratom's contributions to a medically complex presentation and potential kratom-drug interactions due to its posited inhibitory effect on cytochrome P450 enzymes and P-glycoprotein. Our case adds to the growing literature which describes buprenorphine-naloxone as an effective treatment for kratom dependence and withdrawal.

Novel methods for the remote investigation of emerging substances: Application to kratom

The botanical product commonly called "kratom" is still relatively novel to the United States. Like other natural products marketed as supplements, kratom is highly variable, both in terms of the alkaloids naturally occurring in kratom leaves and in terms of processing and formulation. Kratom products sold in the United States are not well-characterized, nor are daily use patterns among regular users. Surveys and case reports have comprised most of the literature on kratom use among humans. To advance our understanding of real-world kratom use, we developed a protocol for the remote study of regular kratom-using adults in the United States. Our study had three aspects implemented in one pool of participants nationwide: an in-depth online survey, 15 days of ecological momentary assessment (EMA) via smartphone app, and the collection and assay of the kratom products used by participants during EMA. Here, we describe these methods, which can be used to investigate myriad drugs or supplements. Recruiting, screening, and data collection occurred between July 20, 2022 and October 18, 2022. During this time, we demonstrated that these methods, while challenging from a logistical and staffing standpoint, are feasible and can produce high-quality data. The study achieved high rates of enrollment, compliance, and completion. Substances that are emerging or novel, but still largely legal, can be productively studied via nationwide EMA combined with assays of shipped product samples from participants. We discuss challenges and lessons learned so other investigators can adapt these methods. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

A multi-modal image fusion workflow incorporating MALDI imaging mass spectrometry and microscopy for the study of small pharmaceutical compounds

Multi-modal imaging analyses of dosed tissue samples can provide more comprehensive insight into the effects of a therapeutically active compound on a target tissue compared to single-modal imaging. For example, simultaneous spatial mapping of pharmaceutical compounds and endogenous macromolecule receptors is difficult to achieve in a single imaging experiment. Herein, we present a multi-modal workflow combining imaging mass spectrometry with immunohistochemistry (IHC) fluorescence imaging and brightfield microscopy imaging. Imaging mass spectrometry enables direct mapping of pharmaceutical compounds and metabolites, IHC fluorescence imaging can visualize large proteins, and brightfield microscopy imaging provides tissue morphology information. Single-cell resolution images are generally difficult to acquire using imaging mass spectrometry, but are readily acquired with IHC fluorescence and brightfield microscopy imaging. Spatial sharpening of mass spectrometry images would thus allow for higher fidelity co-registration with higher resolution microscopy images. Imaging mass spectrometry spatial resolution can be predicted to a finer value via a computational image fusion workflow, which models the relationship between the intensity values in the mass spectrometry image and the features of a high spatial resolution microscopy image. As a proof of concept, our multi-modal workflow was applied to brain tissue extracted from a Sprague Dawley rat dosed with a kratom alkaloid, corynantheidine. Four candidate mathematical models including linear regression, partial least squares regression (PLS), random forest regression, and two-dimensional convolutional neural network (2-D CNN), were tested. The random forest and 2-D CNN models most accurately predicted the intensity values at each pixel as well as the overall patterns of the mass spectrometry images, while also providing the best spatial resolution enhancements. Herein, image fusion enabled predicted mass spectrometry images of corynantheidine, GABA, and glutamine to approximately 2.5 μm spatial resolutions, a significant improvement compared to the original images acquired at 25 μm spatial resolution. The predicted mass spectrometry images were then co-registered with an H&E image and IHC fluorescence image of the μ-opioid receptor to assess co-localization of corynantheidine with brain cells. Our study also provides insight into the different evaluation parameters to consider when utilizing image fusion for biological applications.

Responses to a "Typical" Morning Dose of Kratom in People Who Use Kratom Regularly: A Direct-Observation Study

INTRODUCTION

Use of kratom has outpaced systematic study of its effects, with most studies reliant on retrospective self-report.

METHODS

We aimed to assess acute effects following kratom use in adults who use regularly, and quantify alkaloids in the products, urine, and plasma. Between July and November 2022, 10 adults came to our clinic and orally self-administered their typical kratom dose; blinding procedures were not used. Physiological measures included blood pressure, respiratory rate, heart rate, pulse oximetry, temperature, and pupil diameter. Subjective outcomes included Subjective Opioid Withdrawal Scale, Addiction Research Center Inventory, and Drug Effects Questionnaire. Psychomotor performance was also assessed.

RESULTS

Participants were 6 men and 4 women, mean age 41.2 years. Nine were non-Hispanic White; 1 was biracial. They had used kratom for 6.6 years (SD, 3.8 years) on average (2.0-14.1). Sessions were 190.89 minutes on average (SD, 15.10 minutes). Mean session dose was 5.16 g (median, 4.38 g; range, 1.1-10.9 g) leaf powder. Relative to baseline, physiological changes were minor. However, pupil diameter decreased (right, b = -0.70, P < 0.01; left, b = -0.73, P < 0.01) 40-80 minutes postdose and remained below baseline >160 minutes. Subjective Opioid Withdrawal Scale pre-dosing was mild (5.5 ± 3.3) and decreased postdose (b = [-4.0, -2.9], P < 0.01). Drug Effects Questionnaire "feeling effects" increased to 40/100 (SD, 30.5) within 40 minutes and remained above baseline 80 to 120 minutes (b = 19.0, P = 0.04), peaking at 72.7/100; 6 participants rated euphoria as mild on the Addiction Research Center Inventory Morphine-Benzedrine-scale. Psychomotor performance did not reliably improve or deteriorate postdosing.

CONCLUSIONS

Among regular consumers, we found few clinically significant differences pre- and post-kratom dosing. Alkaloidal contents in products were within expected ranges.

Presence of kratom in opioid overdose deaths: findings from coroner postmortem toxicological report

Background

Kratom (Mitragyna speciosa) use in the United States is becoming increasingly popular and its legal status varies widely from state to state. Multiple reports of adverse events associated with kratom use have ranged from liver injury, seizures, psychiatric disturbance, and rarely death.

Methods

This study investigated coroner autopsy reports from Kern County in California for the year 2020 which included qualitative data on substances from blood toxicological reports. Of the 214 opioid-associated accidental overdoses reported, 4 subjects (1.9%) had mitragynine (kratom) exposure on the autopsy report and were included in the study. We reported available demographic information and comorbid substance findings from the associated autopsy reports.

Results

All 4 individuals with mitragynine (kratom) toxicology had accidental opioid overdose deaths noted in autopsy reports. Each subject also had toxicology positive for at least one other substance. Fentanyl was found in 3 (75%) of the cases and suspected to be the primary contributor to opioid-related deaths in those cases. However, one fatality was without fentanyl, but instead had tested positive for benzodiazepines, cannabis, and other psychiatric medications.

Discussion

The findings of this brief report provide insight into the role that mitragynine (kratom) may have in modulating risk of opioid-related deaths. The combined use of kratom with opioids such as fentanyl appears most likely to increase the risk of a fatal overdose, but it may also occur with other medications such as benzodiazepines and psychiatric medications. It is a serious concern that in the midst of the opioid overdose epidemic there is a growing presence of kratom use in the U.S. population with a largely unregulated status.

Kratom: A Bibliometric Analysis of Scientific Publications

Kratom has caught the attention of governments, policymakers, and academicians due to its unique characteristics. This paper explores the scholarly works related to the different aspects of Kratom to elucidate its research progress and identify future research agendas. We reviewed existing publications on Kratom using a bibliometric methodology. By analyzing 431 scientific publications, we identified publication sources, document analysis, countries analysis, and research keywords, which helped us understand the research locus on Kratom. After reviewing the publications, we discovered significant disagreements in categorizing and defining Kratom amongst authors based on their nationalities. We also showed the knowledge structure of existing publications via thematic analysis, illustrating that the studies focused on the opioid nature of Kratom. Also, drug abuse-related issues evolved as the motor theme of research, while other aspects are prevalent as niche or emerging research themes. This paper contributes to the literature by providing a broad idea of existing literature and offering a comprehensive outlook on Kratom, which could be helpful for policy formulation in the future.

Endogenous Opioid Activity as the Mechanism of Action for Mitragyna speciosa (Kratom): The Current State of the Evidence

Kratom (Mitragyna speciosa) is a substance derived from botanical compounds native to Southeast Asia. This substance has been cultivated predominantly in Thailand, Malaysia, Vietnam, and Myanmar, where it has historically been used in traditional medicine as a near panacea for several health problems. Such ritualistic use of kratom has been present for centuries; however, recreational use appears to have increased globally, especially in the United States. Pharmacodynamic and pharmacokinetic studies have found that kratom demonstrates a unique parabolic, dose-dependent pattern of effects ranging from stimulation to opioid and analgesic effects. Pharmacological research indicates that kratom is both a mu opioid receptor (μ-OR; MOR) and a kappa opioid receptor (κ-OR; KOR) agonist, which mediates its analgesic effects. Other research suggests that kratom may simultaneously act on dopaminergic and serotonergic receptors, which mediate its stimulant effects. This chapter reviews the literature related to the structural, functional, and cultural characteristics of kratom use. We begin with an overview of current and historical patterns of kratom, followed by a review of data on the pharmacodynamics and pharmacokinetics of kratom thus far.

Kratom Retail Availability in Fort Worth, Texas

Kratom use is associated with cannabis use, so retail availability may also be related. Kratom and Delta-8 THC (a psychoactive cannabis product) are federally unregulated, marketed as "natural," and often used for pain relief and/or relaxation. Kratom may have greater retail availability in more socioeconomically deprived areas because harmful substances are frequently marketed to lower-income communities. This study examined kratom retail availability in Fort Worth, Texas. Locations with alcohol, tobacco, and/or CBD licenses were called in July 2022: 1,025/1,223 (84%) answered the phone. T-tests examined potential differences in socioeconomic deprivation scores surrounding outlets by whether they sold kratom. Cross-tabulations examined overlap in kratom and Delta-8 THC availability. Kratom was available in 6% of locations. Most kratom retailers had a tobacco license (92%). However, most stores with a tobacco license did not sell kratom (14%), whereas most stores with a CBD license did (55%). Kratom availability was not associated with area deprivation scores. Most kratom retailers (95%) sold Delta-8 THC and two-thirds (65%) of Delta-8 THC retailers sold kratom. This study was the first to examine retail availability of kratom. Findings indicate the presence of niche stores specializing in the retail of federally unregulated substances.

An update on the clinical pharmacology of kratom: uses, abuse potential, and future considerations

INTRODUCTION

Kratom (Mitragyna speciosa) has generated substantial clinical and scientific interest as a complex natural product. Its predominant alkaloid mitragynine and several stereoisomers have been studied for activity in opioid, adrenergic, and serotonin receptors. While awaiting clinical trial results, the pre-clinical evidence suggests a range of potential therapeutic applications for kratom with careful consideration of potential adverse effects.

AREAS COVERED

The focus of this review is on the pharmacology, pharmacokinetics, and potential drug-drug interactions of kratom and its individual alkaloids. A discussion on the clinical pharmacology and toxicology of kratom is followed by a summary of user surveys and the evolving concepts of tolerance, dependence, and withdrawal associated with kratom use disorder.

EXPERT OPINION

With the increasing use of kratom in clinical practice, clinicians should be aware of the potential benefits and adverse effects associated with kratom. While many patients may benefit from kratom use with few or no reported adverse effects, escalating dose and increased use frequency raise the risk for toxic events in the setting of polysubstance use or development of a use disorder.

Knowledge of Kratom among Alabama Pharmacists

Kratom (Mitragyna speciosa) is a botanical substance whose leaves produce stimulant- and opioid-like effects. Kratom use has increased precipitously in the United States (U.S.) over the last decade, yet, in our experience, many pharmacists are unfamiliar with this herb. The purpose of this study was to assess pharmacists' awareness and knowledge of kratom. This cross-sectional study used an online questionnaire to preferentially solicit community pharmacists' knowledge of kratom and collect demographic information. The survey was sent via email to approximately 10,000 pharmacists, targeting those in the state of Alabama, U.S. Data were analyzed using descriptive statistics, and the Chi Square test was used to compare nominal data. A total of 257 participants responded to the survey. Almost 50% of participants had heard of kratom, and 50% had not. Compared to females, males were more likely to have heard of kratom (64% vs. 42%; p = 0.0015), as were pharmacists who worked for an independent pharmacy vs. a chain (61% vs. 41%; p = 0.025). Of the participants who had heard of kratom, only 14% considered themselves knowledgeable or very knowledgeable about the herb, and only 44% knew it was illegal in Alabama. These data indicate a need to further kratom education among community pharmacists in Alabama.

[Kratom (Mitragyna Speciosa): a Psychoactive Plant with Opportunities and Risks]

Kratom is an evergreen tree that is native to Southeast Asia. Its leafs are traditionally used as a stimulant, a remedy for various health problems and for religious purposes. Especially in the US (in a lesser extent also in Europe) kratom use is significantly prevalent. In Western countries, kratom is used predominantly as an analgesic and stimulant, for the treatment of opioid use disorders, and for improving mental health (e. g., in depression, anxiety disorders). Main molecular constituents of kratom are alkaloids of which mitragynine and 7-hydroxymitragynine appear to be most important. Pharmacodynamics and -kinetics of kratom are complex and insufficiently studied. It is known that mitragynine and 7-hydroxymitragynine are partial agonist at human μ-opioid receptors and antagonists at κ- and δ-opioid receptors with additional effects at other central receptors. Tolerability of kratom is presumably better than that of classical opioids; this is probably due to missing effects of kratom on β-arrestin and discussed as a starting point for the development of opioids with improved tolerability. Some alkaloids of kratom are inhibitors of CYP26 and to a somewhat lesser degree of CYP2C19 and CYP3A4. The addictive potential of kratom appears to be lower than that of classical opioids; however, corresponding data is limited and kratom use disorders appear to occur primarily in Western countries. Several cases of severe health-related problems and deaths are known in the US; in these cases, however, polysubstance use was usually present. Kratom use is likely associated with hepatotoxicity and cardiotoxicity. Kratom-associated mortality and morbidity in Western countries are quantitatively significantly different from Southeast Asia, where kratom use is no public health problem. The reasons for this may be the combined use of substances (which is more prevalent in Western countries), higher dosages of consumed kratom, adulterations and contaminations of commercially available kratom in Western countries, pharmacokinetic interactions, and higher concentrations of 7-hydroxymitragynine in dried kratom leafs (that are typically consumed in Western countries) in comparison to fresh leafs (that are typically consumed in Southeast Asia).

A Critical Review of the Neuropharmacological Effects of Kratom: An Insight from the Functional Array of Identified Natural Compounds

Kratom (Mitragyna speciosa Korth. Havil) has been considered a narcotic drug for years, barred by the law in many parts of the world, while extensive research over the past few decades proves its several beneficial effects, some of which are still in ambiguity. In many countries, including Thailand, the indiscriminate use and abuse of kratom have led to the loss of life. Nonetheless, researchers have isolated almost fifty pure compounds from kratom, most of which are alkaloids. The most prevalent compounds, mitragynine and 7-hydroxy mitragynine, are reported to display agonist morphine-like effects on human μ-opioid receptors and antagonists at κ- and δ-opioid receptors with multimodal effects at other central receptors. Mitragynine is also credited to be one of the modulatory molecules for the Keap1-Nrf2 pathway and SOD, CAT, GST, and associated genes' upregulatory cascades, leading it to play a pivotal role in neuroprotective actions while evidently causing neuronal disorders at high doses. Additionally, its anti-inflammatory, antioxidative, antibacterial, and gastroprotective effects are well-cited. In this context, this review focuses on the research gap to resolve ambiguities about the neuronal effects of kratom and demonstrate its prospects as a therapeutic target for neurological disorders associated with other pharmacological effects.

Discovering Dynamic Plant Enzyme Complexes in Yeast for Kratom Alkaloid Pathway Identification

Discovering natural product biosynthetic pathways of medicinal plants is challenging and laborious. Capturing the coregulation patterns of pathway enzymes, particularly transcriptomic regulation, has proven an effective method to accelerate pathway identification. In this study, we developed a yeast-based screening method to capture the protein-protein interactions (PPI) between plant enzymes, which is another useful pattern to complement the prevalent approach. Combining this method with plant multiomics analysis, we discovered four enzyme complexes and their organized pathways from kratom, an alkaloid-producing plant. The four pathway branches involved six enzymes, including a strictosidine synthase, a strictosidine β-D-glucosidase (MsSGD), and four medium-chain dehydrogenase/reductases (MsMDRs). PPI screening selected six MsMDRs interacting with MsSGD from 20 candidates predicted by multiomics analysis. Four of the six MsMDRs were then characterized as functional, indicating the high selectivity of the PPI screening method. This study highlights the opportunity of leveraging post-translational regulation features to discover novel plant natural product biosynthetic pathways.

The dopamine D1 receptor antagonist SCH-23390 blocks the acquisition, but not expression of mitragynine-induced conditioned place preference in rats

Mitragynine (MG) is the primary active constituent of Mitragyna speciosa Korth (kratom), a psychoactive Southeast Asian plant with potential therapeutic use. Numerous studies support roles of dopaminergic system in drug reward. However, the involvement of the dopaminergic system in mediating MG reward and drug-seeking is poorly understood. Using conditioned place preference (CPP) paradigm, the present study aims to evaluate the roles of the dopamine (DA) D1 receptor in the acquisition and expression of MG-induced CPP in rats. The effects of SCH-23390, a selective DA D1 receptor antagonist, on the acquisition of MG-induced CPP were first investigated. Rats were pre-treated systemically with SCH-23390 (0, 0.1 and 0.3 mg/kg, i.p.) prior to MG (10 mg/kg) conditioning sessions. Next, we tested the effects of the DA D1 receptor antagonist on the expression of MG-induced CPP. Furthermore, the effects of a MG-priming dose (5 mg/kg) on the reinstatement of extinguished CPP were tested. The results showed that SCH-23390 dose-dependently suppressed the acquisition of a MG-induced CPP. In contrast, SCH-23390 had no effect on the expression of a MG-induced CPP. The findings of this study suggested a crucial role of the DA D1 receptor in the acquisition, but not the expression of the rewarding effects of MG in a CPP test. Furthermore, blockade of the D1-like receptor during conditioning did not prevent MG priming effects on CPP reinstatement test, suggesting no role for the DA D1 receptor in reinstatement sensitivity.

Cannabinoid mechanisms contribute to the therapeutic efficacy of the kratom alkaloid mitragynine against neuropathic, but not inflammatory pain

AIMS

Mitragynine (MG) is an alkaloid found in Mitragyna speciosa (kratom), a plant used to self-treat symptoms of opioid withdrawal and pain. Kratom products are commonly used in combination with cannabis, with the self-treatment of pain being a primary motivator of use. Both cannabinoids and kratom alkaloids have been characterized to alleviate symptoms in preclinical models of neuropathic pain such as chemotherapy-induced peripheral neuropathy (CIPN). However, the potential involvement of cannabinoid mechanisms in MG's efficacy in a rodent model of CIPN have yet to be explored.

MAIN METHODS

Prevention of oxaliplatin-induced mechanical hypersensitivity and formalin-induced nociception were assessed following intraperitoneal administration of MG and CB1, CB2, or TRPV1 antagonists in wildtype and cannabinoid receptor knockout mice. The effects of oxaliplatin and MG exposure on the spinal cord endocannabinoid lipidome was assessed by HPLC-MS/MS.

KEY FINDINGS

The efficacy of MG on oxaliplatin-induced mechanical hypersensitivity was partially attenuated upon genetic deletion of cannabinoid receptors, and completely blocked upon pharmacological inhibition of CB1, CB2, and TRPV1 channels. This cannabinoid involvement was found to be selective to a model of neuropathic pain, with minimal effects on MG-induced antinociception in a model of formalin-induced pain. Oxaliplatin was found to selectively disrupt the endocannabinoid lipidome in the spinal cord, which was prevented by repeated MG exposure.

SIGNIFICANCE

Our findings suggest that cannabinoid mechanisms contribute to the therapeutic efficacy of the kratom alkaloid MG in a model of CIPN, which may result in increased therapeutic efficacy when co-administered with cannabinoids.

Translating Kratom-Drug Interactions: From Bedside to Bench and Back

Kratom is a botanical natural product belonging to the coffee family, with stimulant effects at low doses and opioid-like effects at higher doses. During the last two decades, kratom has been purported as a safer alternative to pharmaceutical and illicit drugs to self-manage pain and opioid withdrawal symptoms. Kratom alkaloids, typically mitragynine, have been detected in biologic samples from overdose deaths. These deaths are often observed in combination with other drugs and are suspected to result from polyintoxications. This review focuses on the potential for kratom to precipitate pharmacokinetic interactions with object drugs involved in these reported polyintoxications. The legal status, chemistry, pharmacology, and toxicology are also summarized. The aggregate in vitro and clinical data identified kratom and select kratom alkaloids as modulators of cytochrome P450 (P450) enzyme activity, notably as inhibitors of CYP2D6 and CYP3A, as well as P-glycoprotein-mediated efflux activity. These inhibitory effects could increase the systemic exposure to co-consumed object drugs, which may lead to adverse effects. Collectively, the evidence to date warrants further evaluation of potential kratom-drug interactions using an iterative approach involving additional mechanistic in vitro studies, well designed clinical studies, and physiologically based pharmacokinetic modeling and simulation. This critical information is needed to fill knowledge gaps regarding the safe and effective use of kratom, thereby addressing ongoing public health concerns. SIGNIFICANCE STATEMENT: The botanical kratom is increasingly used to self-manage pain and opioid withdrawal symptoms due to having opioid-like effects. The legal status, chemistry, pharmacology, toxicology, and drug interaction potential of kratom are reviewed. Kratom-associated polyintoxications and in vitro-in vivo extrapolations suggest that kratom can precipitate pharmacokinetic drug interactions by inhibiting CYP2D6, CYP3A, and P-glycoprotein. An iterative approach that includes clinical studies and physiologically based pharmacokinetic modeling and simulation is recommended for further evaluation of potential unwanted kratom-drug interactions.

The Garlic Tree of Borneo, Scorodocarpus borneensis (Baill.) Becc. (Olacaceae): Potential Utilization in Pharmaceutical, Nutraceutical, and Functional Cosmetic Industries

Scorodocarpus borneensis (Baill.) Becc. is attracting increased attention as a potential commercial medicinal plant product in Southeast Asia. This review summarizes the current knowledge on the taxonomy, habitat, distribution, medicinal uses, natural products, pharmacology, toxicology, and potential utilization of S. borneesis in the pharmaceutical/nutraceutical/functional cosmetic industries. All data in this review were compiled from Google Scholar, PubMed, Science Direct, Web of Science, ChemSpider, PubChem, and a library search from 1866 to 2022. A total of 33 natural products have been identified, of which 11 were organosulfur compounds. The main organosulfur compound in the seeds is bis-(methylthiomethyl)disulfide, which inhibited the growth of a broad spectrum of bacteria and fungi, T-lymphoblastic leukemia cells, as well as platelet aggregation. Organic extracts evoked anti-microbial, cytotoxic, anti-free radical, and termiticidal effects. S. borneensis and its natural products have important and potentially patentable pharmacological properties. In particular, the seeds have the potential to be used as a source of food preservatives, antiseptics, or termiticides. However, there is a need to establish acute and chronic toxicity, to examine in vivo pharmacological effects and to perform clinical studies.

The Health Impact of Long-Term Kratom (Mitragyna Speciosa) Use in Southern Thailand

BACKGROUND

Mitragyna speciosa or Kratom has been used in Thailand traditionally for its medicinal value. Despite case reports of kratom consumption causing adverse effects, research on its long-term health impact is limited. This study examines the long-term health impact of kratom use among people in Southern Thailand.

METHODS

Three community-based surveys were conducted from 2011 to 2015. In the first and second surveys (2011 and 2012) a total of 1,118 male respondents comprising 355 regular kratom users, 171 occasional kratom users, 66 ex-users, and 592 non-users aged 25 or above, were recruited from 40 villages. All respondents were followed up in this study. However, not all respondents were successfully followed up throughout the entire set of studies.

RESULTS

Common health complaints were no more common among kratom users than ex- and non-users, but more regular than occasional users claimed kratom to be addictive. Those with high kratom dependence scores were more likely to experience intense withdrawal symptoms, which developed 1-12 h after the last kratom intake. Over half (57.9%) of regular users had experienced intoxication effects compared to only 29.3% of occasional users. Kratom users were less likely to have a history of chronic diseases such as diabetes, hypertension, dyslipidemia than ex- and non-users.

CONCLUSION

Regular long-term chewing of fresh kratom leaves was not related to an increase in common health complaints, but may pose a drug dependence risk. Severe kratom dependents were more likely to suffer from intense withdrawal symptoms. Medical records revealed no death due to traditional kratom use, but the high prevalence of tobacco or/and hand rolled cigarette smoking among kratom users should be of concern.

Kratom: History, pharmacology, current user trends, adverse health effects and potential benefits

Kratom (Mitragyna speciosa Korth.) is a tree native to Southeast Asia with dose-dependent stimulant and opioid-like effects. Dried, powdered leaf material is among the kratom products most commonly consumed in the US and Europe, but other formulations also exist including enriched extracts, resins, tinctures, and edibles. Its prevalence in the US remains debated and the use pattern includes self-treatment of mood disorders, pain, and substance use disorders. Most of the adverse effects of kratom and its alkaloid mitragynine have been reported in the literature as case reports or part of surveys necessitating confirmation by clinical trials. Toxicities associated with kratom consumption have focused on hepatic, cardiac, and CNS effects with the potential to cause fatalities primarily as part of polydrug exposures. Kratom may also present with drug-drug interactions primarily through CYP 3A4 and 2D6 inhibition, although the clinical significance remains unknown to date. The variability in composition of commercially available kratom products complicates generalization of findings and requires further investigation by employing clinical trials. Healthcare professionals should remain cautious in counseling patients on the use of kratom in a therapeutic setting.

Kratom's Emergence and Persistence Within the US Polydrug Epidemic

Purpose of Review

Use of "kratom" products, derived from the bioactive botanical Mitragyna speciosa have increased amidst US polydrug use epidemics. Kratom alkaloids interact with opioid, serotonergic, adrenergic, and other receptors and regular users have described experiencing a wide range of effects. Some with polydrug use histories have reported using kratom as a substitute for other drugs or to nonmedically self-manage substance use disorder (SUD) symptoms. Data describing this remain scare and come from self-report. We review this literature describing kratom use as a drug substitute, or as a nonmedical "self-treatment" for attenuating dependence or SUD symptoms.

Recent Findings

Kratom products have been documented as being used as a licit and illicit opioid substitute. Use to reduce alcohol or stimulant consumption is less well documented. Although prior and current polydrug use appear common among a some kratom users, it is unclear if co-use is contemporaneous or concomitant. Temporal order of use initiation is typically undocumented. Use for energy and recreation are also increasingly reported.

Summary

Data on kratom consumption come primarily from self-report with significant limitations. Until controlled human laboratory studies have been conducted, we can presently only describe what is known about human kratom use based on self-report. Such data describe real-world kratom use, leaving unaddressed human abuse liability or therapeutic potential of kratom alkaloids. Clinicians should be mindful of use motivations among people with SUD histories, sensitively assessing use. The paucity of data highlights the urgent need to increase funding and research for understanding kratom's effects in humans.

Investigating the Impact of Kratom (Mitragyna speciosa) Use Upon Male Sexual Health

Purpose

Kratom (Mitragyna speciosa) exhibits μ-receptor agonism and is used as an opioid substitute. While opioids are known to inhibit sexual behavior, less is known regarding kratom. We conducted a pilot study to assess the subjective impact of kratom upon male sexual health including erectile and ejaculatory function.

Patients and Methods

Twitter and Reddit (r/Kratom) were accessed to disseminate our survey featuring validated instruments (the International Index of Erectile Function, IIEF, and the premature ejaculation diagnostic tool, PEDT). Sexual health prior to and after 4 weeks of kratom use was assessed.

Results

Most males surveyed (n = 165) were 18-40 years old (84.9%), with 95.8% of respondents using it at least weekly and 82.4% using kratom for ≥1 year. Reasons for use included treating pain (39.4%), and mental health conditions (63.6%). Kratom was associated with a positive (37.7%) and negative (20.5%) impact on sexual health. Kratom subjectively increased time to ejaculation in 104 (66.6%) patients, perceived as positive by 62 (59.6%). Seventy-eight patients answered questions about premature ejaculation. The median (with interquartile range, IQR, following;) pre-kratom and kratom use scores were 13.0; 8.0 and 6.5; 5.0, respectively (p < 0.001). Ejaculation before 5 minutes improved after kratom (51.3% vs 12.8%) (p < 0.0001). Following kratom use, patients reported lack of frustration with ejaculation prior to desire (21.8% vs 61.5%) (p < 0.001). The erectile function domain of the IIEF was statistically significantly different however - clinically similar pre-kratom use (29.0; 5.75) versus 27.0; 6.75 during kratom use (p = 0.037).

Conclusion

Clinicians treating male sexual health should be aware of kratom and its potential effect on ejaculatory and erectile function.

Discovering dynamic plant enzyme complexes in yeast for novel alkaloid pathway identification from a medicinal plant kratom

Discovering natural product biosynthetic pathways from medicinal plants is challenging and laborious, largely due to the complexity of the transcriptomics-driven pathway prediction process. Here we developed a novel approach that captures the protein-level connections between enzymes for pathway discovery with improved accuracy. We proved that heterologous protein-protein interaction screening in yeast enabled the efficient discovery of both dynamic plant enzyme complexes and the pathways they organize. This approach discovered complexes and pathways in the monoterpene indole alkaloid metabolism of a medicinal plant, kratom with high success rate. Screening using a strictosidine β-D-glucosidase (MsSGD1) against 19 medium-chain dehydrogenase/reductases (MsMDRs) identified five MsSGD1-MsMDR complexes. Three out of the five interacting MsMDRs were then proven functional, while the remaining 14 non-interacting candidates did not show obvious activities. The work discovered three branched pathways by combining transcriptomics, metabolomics, and heterologous PPI screening and demonstrated a new plant pathway discovery strategy.