Kratom policy: The challenge of balancing therapeutic potential with public safety

Kratom leaf extracts exert hypolipidaemic effects via the modulation of PCSK9 and LDLR pathways in HepG2 cells

Kratom (Mitragyna speciosa (Korth.) Havil.) has been reported to reduce serum lipids. However, the molecular mechanism underlying hypolipidaemic effect of kratom is still unclear. This study aimed to investigate the effects of kratom leaf extracts on hypolipidaemia via the expression of LDLR and PCSK9 in HepG2 cells. Real-time RT-PCR, Western blotting, and flow cytometry analyses revealed that kratom leaf extracts from red-vein and white-vein strains increased LDLR protein expression but decreased that of PCSK9 via downregulation of SREBP-2 and HNF-1α. Furthermore, a confocal laser scanning microscope revealed that kratom leaf extracts from both strains increased LDL uptake into HepG2 cells. The bioactive compounds, e.g., mitragynine, quercetin, and rutin, in kratom leaf extracts from both strains were characterized by LC-MS/MS analysis. Mitragynine also significantly increased LDLR protein expression but decreased that of PCSK9. Molecular docking studies demonstrated that mitragynine had the strongest binding affinity for EGF-A domain of LDLR (- 7.57 kcal/mol), whereas quercetin had the strongest binding affinity for PCSK9 (- 8.45 kcal/mol). In conclusion, kratom leaf extracts from red-vein and white-vein strains possessed hypolipidaemic effects by decreased PCSK9 expression and increased LDLR expression through the modulation of SREBP2 and HNF-1α. Therefore, kratom could serve as a potential supplement for ameliorating hypercholesterolemia.

Unveiling the Complexities of Medications, Substance Abuse, and Plants for Recreational and Narcotic Purposes: An In-Depth Analysis

The complexities surrounding the use of medications, substance abuse, and the recreational use of plants are multifaceted and warrant a comprehensive examination. This review highlights the complexities surrounding the consumption of chemical substances in excess or for non-medical purposes, obtained through legal prescriptions, over-the-counter purchases, or illicit means, with an emphasis on the predictive role of stressors and individual-level variables in the development of substance use disorders, as well as the influence of the regulatory environment on patterns of consumption. Additionally, the alarming escalation in the mortality rate associated with illicit drug and opioid overdoses is also underscored. The recreational use of prescription medications can lead to significant health risks, particularly when combined with other substances; therefore, the need for interventions and preventive measures to address substance abuse among various populations is imperative. Furthermore, novel insights on substance abuse addiction, exploring the neurobiological mechanisms underlying addiction, and discussing treatment approaches and interventions are elucidated. Advancements in technology for detecting substance abuse are also highlighted, displaying innovative tools for more effective identification and monitoring. In conclusion, the complexities of medications, substance abuse, and the recreational use of plants reveal a landscape marked by overlapping motivations and health implications. The distinction between medical and recreational use is critical for understanding user behavior and addressing public health concerns.

Network Pharmacology, Molecular Docking, and In Vitro Insights into the Potential of Mitragyna speciosa for Alzheimer's Disease

Mitragyna speciosa Korth. Havil (MS) has a traditional use in relieving pain, managing hypertension, treating cough, and diarrhea, and as a morphine substitute in addiction recovery. Its potential in addressing Alzheimer's disease (AD), a neurodegenerative condition with no effective treatments, is under investigation. This study aims to explore MS mechanisms in treating AD through network pharmacology, molecular docking, and in vitro studies. Using network pharmacology, we identified 19 MS components that may affect 60 AD-related targets. The compound-target network highlighted significant interactions among 60 nodes and 470 edges, with an average node degree of 15.7. The KEGG enrichment analysis revealed Alzheimer's disease (hsa05010) as a relevant pathway. We connected 20 targets to tau and β-amyloid proteins through gene expression data from the AlzData database. Docking studies demonstrated high binding affinities of MS compounds like acetylursolic acid, beta-sitosterol, isomitraphylline, and speciophylline to AD-related proteins, such as AKT1, GSK3B, NFκB1, and BACE1. In vitro studies showed that ethanolic (EE), distilled water (DWE), and pressurized hot water (PHWE) extracts of MS-treated 100 μM H2O2-induced SH-SY5Y cells significantly reduced oxidative damage. This research underscores the multi-component, multi-target, and multi-pathway effects of MS on AD, providing insights for future research and potential clinical applications.

A social media analysis of kratom use to discontinue stimulants

BACKGROUND

While FDA-approved treatments exist for opioid use disorder, none are available for stimulant use disorder. Kratom (Mitragyna speciosa), an unregulated plant-derived substance with known opioid- and stimulant-like effects, has been used to self-treat opioid use disorder; however, its use in relation to stimulant use disorder has not been described.

OBJECTIVE

To understand whether and how individuals use kratom to self-treat stimulant use disorder.

METHODS

Using a commercially available social listening platform, 3,820 publicly available social media posts published between January 1, 2020, and June 21, 2021, were reviewed for relevance to kratom and stimulant discontinuation. Manual qualitative thematic analysis was conducted on relevant data.

RESULTS

Among the 398 relevant posts that discussed using kratom to discontinue stimulants, motivations and methods varied considerably. Posts predominantly identified benefits but also negative outcomes of kratom use. Some justified it as necessary despite consequences, while others reported a desire to quit.

CONCLUSIONS

Although there is some awareness that kratom is used to self-treat opioid use disorder, its use to treat stimulant use disorder is more novel. In the absence of approved treatments, kratom was viewed as a natural and safe way to quit stimulants. Despite some reported success, this study shows self-treatment may pose significant risks, including kratom addiction and physical dependence. Healthcare practitioners, researchers, and public health professionals may benefit from understanding motivations for kratom use, associated benefits and risks, and the importance of discussing kratom use with patients/clients who have stimulant use disorder.

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.

A Preliminary Inventory of Kratom (Mitragyna Speciosa) Products and Vendors on the Darknet and Cryptomarkets

In recent years, the online sale of kratom (Mitragyna speciosa), a Southeast Asian plant with both medicinal and psychoactive properties, has raised health concerns mainly due to the uncontrolled diffusion of adulterated kratom-related products. This exploratory study provides, for the first time, a snapshot of the availability of kratom products on the darknet which has been further validated by data searches on the surface web. A total of 231 listings of kratom across 23 darknet marketplaces were identified between March 2020 and October 2021. Among these, 40 were found actively sold across five markets by thirteen vendors. Listed items were mainly advertised as "safe" substitutes for medicinal products for the self-management of pain and other health conditions and offered in various forms (e.g., dry leaf powder, pills, capsules). Purchases were made using cryptocurrencies, with some vendors offering Pretty Good Privacy, and were shipped from Europe, Australia, the United States, and the United Kingdom. Goods sold by the same sellers also included illicit drugs and fraud-related products. Our study discovered a previously unknown diffusion of kratom products on the darknet mainly for self-treating a variety of medical conditions, suggesting the need for further research and immediate interventions to safeguard the well-being and health of kratom consumers.

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.

Associations Between Kratom-Related State Policy Environments and Kratom Use in a Nationally Representative Population in the United States

Limited research has resulted in conflicting views on the risks versus benefits associated with kratom use. Despite no federal policy in the United States, individual states have implemented diverging policies through kratom bans, and legalization and regulation through Kratom Consumer Protection Acts (KCPAs). The Survey of Non-Medical Use of Prescription Drugs (NMURx) Program employs nationally-representative, repeated cross-sectional surveys on drug use. In 2021, weighted prevalence of past-12 month kratom use was compared across three state legal frameworks: no overarching state policy, KCPAs, and state bans. There was lower estimated prevalence of kratom use in banned states (prevalence: 0.75% (0.44, 1.06) relative to states with a KCPA (1.20% (0.89, 1.51)), and relative to states with no policies (1.04% (0.94, 1.13), though odds of use were not significantly associated with policy type. Kratom use was significantly associated with medicated treatment for opioid use disorder. While there were observed differences in the prevalence of past-12 month kratom use by state policy type, low uptake mitigated meaningful distinctions by limiting statistical precision, and potentially confounding effects, such as accessibility online. Future kratom-related policy decisions should be informed through evidence-based research.

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.

Kratom safety and toxicology in the public health context: research needs to better inform regulation

Although kratom use has been part of life for centuries in Southeast Asia, the availability and use of kratom in the United States (US) increased substantially since the early 2000s when there was little information on kratom pharmacology, use patterns, and effects, all critical to guiding regulation and policy. Here we provide a synthesis of research with several hundred English-language papers published in the past 5 years drawing from basic research, epidemiological and surveillance data, and recent clinical research. This review of available literature aims to provide an integrated update regarding our current understanding of kratom's benefits, risks, pharmacology, and epidemiology, which may inform United States-based kratom regulation. Recent surveillance indicates there are likely several million past-year kratom consumers, though estimates vary widely. Even without precise prevalence data, kratom use is no longer a niche, with millions of United States adults using it for myriad reasons. Despite its botanical origins in the coffee tree family and its polypharmacy, kratom is popularly characterized as an opioid with presumed opioid-system-based risks for addiction or overdose. Neuropharmacology, toxicology, and epidemiology studies show that kratom is more accurately characterized as a substance with diverse and complex pharmacology. Taken together the work reviewed here provides a foundation for future scientific studies, as well as a guide for ongoing efforts to regulate kratom. This work also informs much-needed federal oversight, including by the United States Food and Drug Administration. We conclude with recommendations for kratom regulation and research priorities needed to address current policy and knowledge gaps around this increasingly used botanical product.

Kratom as a potential substance use disorder harm reduction agent

Substance use disorders contribute to considerable U.S. morbidity and mortality. While effective pharmacotherapy options are available to treat opioid and alcohol use disorders, for a variety of reasons, many patients lack access to treatment or may be reluctant to seek care due to concerns such as perceived stigma or a current lack of desire to completely curtail their substance use. Furthermore, treatment options are limited for patients with stimulant or polysubstance use disorders. Thus, there is considerable need to expand the substance use disorder harm reduction armamentarium. Kratom (Mitragyna speciosa Korth.) is an herbal substance that can produce both opioid and stimulant-like effects, and its use in the US is growing. Though there are concerns regarding adverse effects, dependence risk, and limited regulation of its manufacturing and sale, the pharmacology of kratom and early preclinical studies suggest a potential role as a harm reduction agent for various substance use disorders, and it has historically been used in Southeast Asia for such purposes. The goal of this review is to describe kratom's history of use, pharmacology, and early pre-clinical and observational research regarding its therapeutic potential in opioid use disorder, as well as alcohol, stimulant, and polysubstance use disorders, while also highlighting current concerns around its use, existing gaps in the literature, and directions for future research.

Prevalence, Characteristics, and Reasons for Kratom Use among Psychiatrically Ill Inpatients Who Use Substances

OBJECTIVE

Despite kratom impacting neurobiological systems involved in psychiatric disorders, little is known about the prevalence of use among patients with severe psychopathologies. Here, we investigated the prevalence of kratom use, motives for use, and the clinical associations among inpatients with severe psychiatric disorders.

METHODS

A total of 578 patients, aged 18 to 65, were evaluated by New Hampshire Hospital's Addiction Services from January 1, 2020, to February 28, 2022. The study collected demographic information and used chi-square tests, multivariable logistic regression, and subgroup analyses with 95% confidence intervals to examine trends among kratom users. A receiver operating characteristic curve analysis was also conducted. All statistical tests were performed using IBM SPSS Version 28.0.1.

RESULTS

Of the patients assessed, 2.2% (n = 13) reported using kratom. The reasons for kratom use were managing withdrawal symptoms (15.4%), maintaining sobriety and reducing cravings for opioids (53.8%), improving focus and concentration (30.8%), alleviating low moods (38.5%), and managing pain (15.4%). Compared to non-kratom users, the only factor with a fair to good association with kratom use is postsecondary education (Area Under Curve, AUC = 0.77).

CONCLUSIONS

Prevalence of kratom use among patients with serious mental illness at our site aligns with that reported in the general population. Users often cite self-management of cravings and sobriety from opioids, as well as treatment of low mood states, as motivations for consumption. While observations suggest a possible association between kratom use and individuals with post-secondary education, multiple substance use, and experience of substance-induced psychosis or mood disorders, it is essential to interpret these links cautiously until further rigorous studies are carried out to substantiate these findings.

Screening and confirmation of psilocin, mitragynine, phencyclidine, ketamine and ketamine metabolites by liquid chromatography-tandem mass spectrometry

A safe and productive workplace requires a sober workforce, free from substances that impair judgment and concentration. Although drug monitoring programs already exist, the scope and loopholes of standard workplace testing panels are well known, allowing other substances to remain a source of risk. Therefore, a high-throughput urine screening method for psilocin, mitragynine, phencyclidine, ketamine, norketamine and dehydronorketamine was developed and validated in conjunction with a urine and blood confirmation method. There are analytical challenges to overcome with psilocin and mitragynine, particularly when it comes to drug stability and unambiguous identification in authentic specimens. Screening and confirmation methods were validated according to the American National Standards Institute/Academy Standards Board (ANSI/ASB) Standard 036, Standard Practices for Method Validation in Forensic Toxicology. An automated liquid handling system equipped with dispersive pipette extraction tips was utilized for preparing screening samples, whereas an offline solid-phase extraction method was used for confirmation sample preparation. Both methods utilized liquid chromatography-tandem mass spectrometry to achieve limits of detection between 1-5 ng/mL for the screening method and 1 ng/mL for the confirmation method. Automation allows for faster throughput and enhanced quality assurance, which improves turnaround time. Compared to previous in-house methods, specimen volumes were substantially decreased for both blood and urine, which is an advantage when volume is limited. This screening technique is well suited for evaluating large numbers of specimens from those employed in safety-sensitive workforce positions. This method can be utilized by workplace drug testing, human performance and postmortem laboratories seeking robust qualitative screening and confirmation methods for analytes that have traditionally been challenging to routinely analyze.

Human Mitragynine and 7-Hydroxymitragynine Pharmacokinetics after Single and Multiple Daily Doses of Oral Encapsulated Dried Kratom Leaf Powder

Kratom leaves, consumed by millions worldwide as tea or ground leaf powder, contain multiple alkaloids, with mitragynine being the most abundant and responsible for most effects. Mitragynine is a partial µ-opioid receptor agonist and competitive antagonist at κ- and δ-opioid receptors; however, unlike morphine, it does not activate the β-arrestin-2 respiratory depression pathway. Due to few human mitragynine data, the largest randomized, between-subject, double-blind, placebo-controlled, dose-escalation study of 500-4000 mg dried kratom leaf powder (6.65-53.2 mg mitragynine) was conducted. LC-MS/MS mitragynine and 7-hydroxymitragynine plasma concentrations were obtained after single and 15 daily doses. Mitragynine and 7-hydroxymitragynine Cmax increased dose proportionally, and AUC was slightly more than dose proportional. The median mitragynine Tmax was 1.0-1.3 h after single and 1.0-1.7 h after multiple doses; for 7-hydroxymitragynine Tmax, it was 1.2-1.8 h and 1.3-2.0 h. Steady-state mitragynine concentrations were reached in 8-9 days and 7-hydroxymitragynine within 7 days. The highest mean mitragynine T1/2 was 43.4 h after one and 67.9 h after multiple doses, and, for 7-hydroxymitragynine, it was 4.7 and 24.7 h. The mean 7-hydroxy-mitragynine/mitragynine concentration ratios were 0.20-0.31 after a single dose and decreased (0.15-0.21) after multiple doses. These mitragynine and 7-hydroxymitragynine data provide guidance for future clinical kratom dosing studies and an interpretation of clinical and forensic mitragynine and 7-hydroxymitragynine concentrations.

Ecological Momentary Assessment of Self-Reported Kratom Use, Effects, and Motivations Among US Adults

Importance

Kratom products, which are sold legally in most of the US, contain alkaloids with opioidergic, adrenergic, and serotonergic activity. Millions of people use kratom to relieve pain, improve mood, or self-manage substance use disorders (SUDs). Kratom use has primarily been examined via surveys, in which recall biases among satisfied users may lead to minimization of transient negative outcomes. Further prospective study of kratom use, such as with ecological momentary assessment (EMA), is needed.

Objective

To characterize proximal motivators, effects, and patterns of kratom use and to assess whether use frequency is associated with motivations, effects, past-year criteria for SUD for kratom (KUD), or other substance use.

Design, Setting, and Participants

For this prospective cross-sectional study, an intensive longitudinal smartphone-based EMA in which participants' current behaviors and experiences were repeatedly sampled in real time was conducted between July 1 and October 31, 2022. Participants comprised a convenience sample of US adults who used kratom at least 3 days per week for at least 4 weeks at the time of online screening. Criteria for past-year KUD were based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Data analysis was performed between November 2022 and November 2023.

Exposure

The exposure was 13 401 kratom-use events across 15 days.

Main Outcomes and Measures

A baseline survey covering demographics, health, kratom attitudes and behaviors, use motivations, other substance use, and KUD was administered before EMA. Data for the following EMA entries were then collected: event-contingent entries for kratom use (product, dose, and proximal motivations), follow-up entries (short-term effects and consequences of use events), random-prompt entries (mood), beginning-of-day entries (effects of kratom on sleep), and end-of-day entries (daily subjective descriptions of kratom effects). Bayesian regression was used to estimate means and credible intervals.

Results

A total of 357 participants completed the EMA. Their mean (SD) age was 38.0 (11.1) years; more than half were men (198 [55.5%]). Participants reported overall motivators of use on the baseline survey that involved managing psychiatric and SUD problems, but proximal motivators evaluated during the EMA involved situation-specific needs such as increasing energy and productivity and decreasing pain. Acute effects were considered congruent with daily obligations. Use patterns, despite having some distinguishing features, were generally similar in their motivators and effects; participants used kratom predominantly during the daytime and seemed to find use frequencies that suited their needs. Higher use patterns were associated with symptoms of physical dependence (eg, withdrawal or tolerance). Co-used substances included caffeine, nicotine, vitamins, and cannabis.

Conclusions and Relevance

Most participants in this study reported using kratom in a seemingly nonproblematic way. When such use appeared problematic, the key element was usually that withdrawal avoidance became a proximal motivator. Longitudinal studies examining changes in kratom use patterns and effects over time are needed.

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.

Kratom (Mitragyna speciosa): A Case Review of Use Before and During Pregnancy

Kratom (Mitragyna speciosa) is a plant-based substance with psychoactive properties similar to opioids but is not currently classified as an opioid. One of its more prevalent uses is to treat opioid dependency and withdrawal symptoms. Opioid use disorder is a leading cause of pregnancy-associated maternal mortality, and pregnant women may be using kratom as a substitute or alternative to opioids. Prevalence of kratom use is increasing rapidly, but scientific evidence specific to therapeutic and adverse effects is lacking overall, and the implications of its use in pregnancy and on the fetus-newborn are limited to a few case reports. Kratom is a legal substance by federal law, although some states have banned its use. The lack of regulation is concerning. Significant illness and associated deaths have been reported with kratom use. Lack of disclosure by people using kratom and limited laboratory testing options are major challenges for health care providers and public health.

Kratom (Mitragyna speciosa) use in a sample of drug-dependent adolescents in rehabilitation for drug use in Malaysia

BACKGROUND

Leaves derived from the Kratom (Mitragyna speciosa) tree have been traditionally ingested for their curative properties by diverse groups of the population including people who use drugs (PWUDs) in Southeast Asia. This study investigated the motives for using kratom among drug-dependent adolescents.

METHODS

Eighty adolescents who were undergoing mandatory drug rehabilitation volunteered to participate in this mixed-method, cross-sectional study. All respondents answered a semi-structured questionnaire while a few were interviewed in-depth.

RESULTS

The majority were males (70%, n = 56/80). The respondents' mean age at admission was 18.2 years (SD = 1.40), and 65% were between 14 and 18 years old. Sixty-three percent (n = 50/80) had used crystal methamphetamine alone, while the rest had co-used crystal methamphetamine with heroin. About three-fifths (60%, n = 48/80) had a history of kratom use. Kratom was commonly used for many perceived benefits such as increasing energy, reducing crystal methamphetamine intake, intensifying euphoria, easing heroin withdrawal, as a heroin substitute and reducing heroin use. In addition, the multivariate analysis indicated that higher odds of kratom use were associated with those who were employed, used only crystal methamphetamine, were recent drug users, and had no prior incarceration history.

CONCLUSION

While kratom was being used for its multifold perceived benefits, it also functions as a means to self-treat withdrawal from illicit drug use among drug-dependent adolescents.

[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 Pilot Study of the Striatal Dopamine Transporter Levels in Kratom-Dependent and Normal Subjects Using 99mTc-TRODAT-1 Single Photon Emission Computed Tomography-Computed Tomography (SPECT-CT)

OBJECTIVE

The study aims to elucidate the effects of kratom addiction on dopamine transporter (DAT) using [2-[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3.2.1]oct-2-yl]methyl](2-mercaptoethyl)amino]ethyl]amino]ethanethiolato(3-)-N2,N20,S2,S20]oxo-[1R-(exo-exo)]-[99mTc] technetium (99mTc-TRODAT-1) brain single photon emission computed tomography-computed tomography (SPECT-CT) in kratom-dependent and healthy subjects.

MATERIALS AND METHODS

We recruited 12 kratom-dependent subjects and 13 healthy men to participate in this study. Addiction, craving, depression, and cognitive scores were assessed. All subjects received a single bolus injection of 99mTc-TRODAT-1 with 914.1 MBq ± 65.5 of activity (mean ± SD). The brain SPECT-CT images were reconstructed using 3D ordered subset expectation maximization (3D-OSEM) along with attenuation correction (AC), scatter correction (SC), and resolution recovery (RR) with an iteration number of four and a subset of 10. The Cohen's Kappa interrater-reliability between two raters, the standardized uptake value of body weight (SUVBW), and the asymmetrical index percentage (AI%) were evaluated.

RESULTS

Kappa statistics showed a fine agreement of abnormal 99mTc-TRODAT-1 uptake in the striatum region for the kratom-dependent group with the κ value of 0.69 (p = 0.0001), and the percentage of agreement for rater 1 and rater 2 was 56% and 64%, respectively. There was a reduction in average SUV in kratom-dependent subjects compared to healthy control subjects in the left caudate and left striatum (0.938 vs. 1.251, p = 0.014, and 1.055 vs. 1.29, p = 0.036, respectively). There was a significant difference in the AI% of the caudate region between the kratom-dependent group and the normal group (33% vs. 14%, p = 0.019).

CONCLUSION

Our findings signify that kratom addiction, may cause a change in DAT level and the results can be confirmed using 99mTc-TRODAT-1 SPECT-CT.

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.

Pharmacokinetic and Pharmacodynamic Consequences of Cytochrome P450 3A Inhibition on Mitragynine Metabolism in Rats

Mitragynine, an opioidergic alkaloid present in Mitragyna speciosa (kratom), is metabolized by cytochrome P450 3A (CYP3A) to 7-hydroxymitragynine, a more potent opioid receptor agonist. The extent to which conversion to 7-hydroxymitragynine mediates the in vivo effects of mitragynine is unclear. The current study examined how CYP3A inhibition (ketoconazole) modifies the pharmacokinetics of mitragynine in rat liver microsomes in vitro. The study further examined how ketoconazole modifies the discriminative stimulus and antinociceptive effects of mitragynine in rats. Ketoconazole [30 mg/kg, oral gavage (o.g.)] increased systemic exposure to mitragynine (13.3 mg/kg, o.g.) by 120% and 7-hydroxymitragynine exposure by 130%. The unexpected increase in exposure to 7-hydroxymitragynine suggested that ketoconazole inhibits metabolism of both mitragynine and 7-hydroxymitragynine, a finding confirmed in rat liver microsomes. In rats discriminating 3.2 mg/kg morphine from vehicle under a fixed-ratio schedule of food delivery, ketoconazole pretreatment increased the potency of both mitragynine (4.7-fold) and 7-hydroxymitragynine (9.7-fold). Ketoconazole did not affect morphine's potency. Ketoconazole increased the antinociceptive potency of 7-hydroxymitragynine by 4.1-fold. Mitragynine (up to 56 mg/kg, i.p.) lacked antinociceptive effects both in the presence and absence of ketoconazole. These results suggest that both mitragynine and 7-hydroxymitragynine are cleared via CYP3A and that 7-hydroxymitragynine is formed as a metabolite of mitragynine by other routes. These results have implications for kratom use in combination with numerous medications and citrus juices that inhibit CYP3A. SIGNIFICANCE STATEMENT: Mitragynine is an abundant kratom alkaloid that exhibits low efficacy at the μ-opioid receptor (MOR). Its metabolite, 7-hydroxymitragynine, is also an MOR agonist but with higher affinity and efficacy than mitragynine. Our results in rats demonstrate that cytochrome P450 3A (CYP3A) inhibition can increase the systematic exposure of both mitragynine and 7-hydroxymitragynine and their potency to produce MOR-mediated behavioral effects. These data highlight potential interactions between kratom and CYP3A inhibitors, which include numerous medications and citrus juices.

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.

Drug testing for mitragynine and kratom: Analytical challenges and medico-legal considerations

Mitragyna speciosa, known as kratom, is a tropical tree native to Southeast Asia that has long been used to increase energy and in traditional medicine. Kratom leaves contain several indole alkaloids including mitragynine, mitraciliatine, speciogynine, and speciociliatine, which have the same molecular formula and connectivity, but different spatial arrangements (i.e., diastereomers). A routine liquid-chromatographic-high-resolution mass-spectrometric (LC-HRMS) multi-analyte method for addictive and herbal drugs in urine did not separate mitragynine from speciogynine and speciociliatine. Separation and individual measurement of the four diastereomers was possible with an improved LC method. All diastereomers were detected in 29 patient urine samples who tested positive for mitragynine with the routine method, albeit at variable absolute amounts and relative proportions. The presence of all diastereomers rather than individual substances indicated that they originated from the intake of kratom (i.e., plant material). Speciociliatine dominated in most samples (66%), whereas mitragynine and mitraciliatine were the highest in 17% each. A kratom product (powdered plant material) marketed in Sweden contained all diastereomers with mitragynine showing the highest level. In Sweden, there are signs of an increasing use of kratom in society, based on the results from drug testing, the number of poisons center consultations on intoxications, and customs seizure statistics. Because there may be health risks associated with kratom use, including dependence, serious adverse reactions, and death, analytical methods should be able to identify and quantify all diastereomers. In Sweden, this is important from a legal perspective, as only mitragynine is classified, whereas the other three diastereomers, and kratom (plant material), are not.

Analysis of Mitragynine and Speciociliatine in Umbilical Cord by LC-MS-MS for Detecting Prenatal Exposure to Kratom

Kratom is an herbal drug that is legal in the USA. While it is marketed as a safer alternative to opioids, it can cause opioid-like withdrawal symptoms when discontinued after regular use. Several case studies have shown that kratom exposure in utero can lead to symptoms in newborns consistent with neonatal abstinence syndrome. Here, we present a validated method for the detection of kratom in umbilical cord by liquid chromatography--tandem mass spectrometry. The umbilical cord is homogenized in solvent and kratom analytes are purified by solid phase extraction (strong cation exchange). Diastereomeric kratom alkaloids mitragynine (MG), speciociliatine (SC), speciogynine and mitraciliatine are separated by reverse phase chromatography on a phenyl-hexyl column. Applying this method to residual umbilical cords submitted to our laboratory for drug testing, 29 positive specimens exhibiting varied kratom analyte distributions were observed. MG and SC were the most abundant kratom analytes and were selected as biomarkers of kratom exposure. A cutoff concentration of 0.08 ng/g was established for both MG and SC.

Exploring adolescents' practice and perspective on the use and misuse of kratom in northwest Malaysia

Kratom is a plant homogenous to Southeast Asia with a long history of traditional use as medicinal herbs. However, recent years have witnessed its pervasive infiltration into international audience with growing public health concern. This cross-sectional study was conducted from 1 August 2017 till 31 August 2018 aiming to explore the practice and perspectives of kratom use and misuse among adolescents in northwest Malaysia. The study involved a self-administered questionnaire that was designed for the purpose of the study. The instrument had undergone prior validation process with a good overall internal reliability for the knowledge domain (Cronbach's alpha = 0.728) and attitude domain (Cronbach's alpha = 0.700). The questionnaire was distributed to 135 respondents involving adolescents aged 13 to 19 years old via convenience (non-kratom user) and snowball sampling (kratom users). There were 65 (47.8%) kratom users, while 70 (51.5%) were kratom-naïve. Among the kratom users, peer influence was the most common reason for them to be first involved with kratom, 26 (41.3%) whereas the reasons for kratom use quoted were to improve physical stamina, 10 (16.4%), as painkiller, 9 (14.8%), and to be accepted by peers, 7 (11.5%). Multiple logistic regression found that older age (95% CI: 0.13, 0.58; p = 0.001) and being active smokers (95% CI: 39.33, 980.63; p < 0.001) significantly predict kratom use among adolescents. The emerging trend of kratom abuse and misuse especially among the younger generation in Malaysia is raising concern and warrants social and governmental vigilance.

Controversial usages of kratom (Mitragyna speciosa): For good or for evil

Kratom (Mitragyna speciosa) is a plant that grows well in tropical climates such as in Southeast Asia. Traditionally, people discovered it possessed a stimulating effect that relieved tiredness. Furthermore, it contains analgesic and medicinal properties for the treatment of pain, diarrhea, muscle discomfort, and blood pressure and to enhance stamina. Nevertheless, long term or regular consumption of kratom leads to addiction. This is because the main alkaloid of kratom, mitragynine, binds to opioid receptors and exerts a euphoric effect similar to that of morphine, which may lead to death. Due to this reason, kratom has been listed as a regulated substance in many countries including the United States, Thailand, Malaysia, Bhutan, Finland, Lithuania, Denmark, Poland, Sweden, Australia, and Myanmar. Usages of kratom carry two pharmacological effects depending on dosage. Low-dose kratom exerts a stimulating effect that refreshes the user. High-dose kratom exerts sedative effects that can lead to addiction similar to that of morphine. Despite the euphoric effect of kratom, the beneficial values of kratom to human health is indisputable. Therefore, a complete banning of kratom may cause a loss to pharmaceutical industry. Rather, a controlled or selective usage of kratom will be a better choice.

Qualitative content analysis of public responses to an FDA inquiry on the impact of scheduling changes to kratom

BACKGROUND

The legal status of kratom in the United States is complex and varies by state. The U.S. Food and Drug Administration (FDA) and the U.S. Drug Enforcement Administration have repeatedly subjected kratom to regulatory review. However, there hasn't been a systematic review of the public's perception of kratom. The present study analyzed open-ended responses from the public to an FDA solicitation for information regarding kratom with the goal of providing a comprehensive assessment of motives for kratom use.

METHODS

To guide decisions regarding kratom regulation, the FDA solicited comments regarding kratom abuse potential, medical usefulness, and impact of scheduling changes from July through August 2021 and posted them to the Federal Register website. We analyzed comments posted during the first 6 weeks of comment solicitation (6,353) using an inductive approach via qualitative content analysis.

RESULTS

Respondents reported 106 independent health-related reasons for kratom use, with most categorized as mental health, pain management, substance use disorder, or miscellaneous purposes that included increasing focus, treating insomnia, and decreasing fatigue. Neurological diseases and digestive disorders were also reported. Relatively few (< 2%) responses reported recreational use, abuse potential, or adverse effects of kratom.

CONCLUSIONS

Although kratom is not approved as a safe and effective therapy for any indication, individuals use kratom for a broad spectrum of health-related purposes. Limitations of this study include potential bias for respondents with perceived positive experiences using kratom, lack of demographics data, and lack of independent verification of claims made by respondents. Regardless, this study reflects perceptions regarding the therapeutic uses of kratom and provides insight into potential individual-level consequences of regulating kratom in the U.S. It is important to study the public's perception of kratom use, which can aid regulatory purposes and provide clinically important information on individuals' use and valuation of kratom.

Clinical Management of Opioid Withdrawal

Appropriate clinical management of opioid withdrawal is a crucial bridge to long-term treatment for opioid use disorder (OUD), because it is a high-risk time for potential opioid overdose and relapse. We provide a narrative review of evidence-based opioid withdrawal management strategies applicable to a variety of treatment settings and geographies. The goals of opioid withdrawal management include relieving suffering associated with withdrawal, providing appropriate diagnosis and screening, engaging patients in initiation of OUD treatment, and using harm reduction strategies, all guided by a patient-centered approach to care. In addition, we discuss complex cases, relapse prevention strategies, and new developments in opioid withdrawal management.

Public Health Implications and Possible Sources of Lead (Pb) as a Contaminant of Poorly Regulated Kratom Products in the United States

Kratom (Mitragyna speciosa) is a tropical tree that is indigenous to Southeast Asia. Kratom leaf products have been used in traditional folk medicine for their unique combination of stimulant and opioid-like effects. Kratom is being increasingly used in the West for its reputed benefits in the treatment of pain, depression, and opioid use disorder (OUD). Recent studies from the United States Food and Drug Administration (FDA, Silver Spring, MD, USA) and our laboratory have shown that many kratom products being sold in the United States are contaminated with potentially hazardous levels of lead (Pb). In this commentary, we discuss the public health implications of the presence of Pb in kratom products, particularly as they relate to the predicted levels of Pb exposure among kratom users. We also considered the specific toxic effects of Pb and how they might relate to the known physiologic and toxicologic effects of kratom. Finally, we consider the possible sources of Pb in kratom products and suggest several areas for research on this issue.

Exploring the self-reported motivations of kratom (Mitragyna speciosa Korth.) use: a cross-sectional investigation

Background: Kratom (Mitragyna speciosa Korth.) use outside of Southeast Asia has increased over the past decade. Objectives: This investigation clarifies kratom's role in perceived well-being, overall health, and temporal correlation with drug use to understand kratom's role in the self-treatment of substance use disorders (SUDs). Methods: Between July 2019 and July 2020 an anonymous, cross-sectional, online survey was taken by 7,381 people who use kratom (PWUK) recruited through social media and other online resources. This included an assessment of (a) the relationship between self-reported overall health, concomitant use of drugs of misuse, and demographics; (b) the perceived effectiveness of kratom in self-treating diagnosed health conditions or symptoms; (c) the profile of PWUK primarily for drug dependence, pain, and mood or mental health conditions based on demographics. Results: A total of 5,152 valid responses (45.9% females/53.7% males) were collected. Kratom was primarily used for self-treating pain (73.0%) and improving emotional or mental health conditions (42.2%) without clinical supervision. Those with a SUD (synthetic opioids, methadone, benzodiazepines, or heroin) used kratom after discontinuing illicit or other drugs (94.8%). The primary substances taken before or concomitantly with kratom were cannabis, cannabidiol, benzodiazepines, or kava. PWUKs report a dose-dependent benefit for alleviating pain and relieving negative moods. Adverse effects were primarily gastrointestinal, typically at high (>5 g/dose) and frequent (>22 doses/week) dosing. Conclusions: Kratom was primarily used as a harm-reduction agent for SUDs and self-treatment of chronic conditions. Healthcare professionals need better information about kratom, its potential adverse effects, and clinically significant drug interactions.

Need for clarity and context in case reports on kratom use, assessment, and intervention

This Letter to the Editor is a response to Broyan and colleagues who recently published a Case Report presenting data on 28 patients in the United States who identified kratom as their primary substance of use and who were subsequently induced on buprenorphine/naloxone for a reported diagnosis of kratom use disorder. We applaud the authors for helping to advance the science on kratom and recognize the difficulties in conducting kratom-related clinical assessment and research. However, a number of inconsistences and generalizations were identified in this Case Report, which also lacked some critical context. Importantly, such inconsistencies and generalizations can be observed throughout kratom-specific case reports. We feel this is now an important opportunity to highlight these issues that are present in the Broyan and colleagues Case report but emphasize that they are not unique to it. We do this with the hope that by acknowledging these issues it can help inform editors, clinicians, and researchers who may not be familiar with kratom and, as a result of this unfamiliarity, may inadvertently present findings in a manner that could confuse readers and even misinform clinical researchers and practitioners.

Health Effects Associated With Kratom (Mitragyna speciosa) and Polysubstance Use: A Narrative Review

Background

Kratom (Mitragyna speciosa) consumption and associated health effects have raised debates in the United States. Although most people using this herb do not experience adverse health effects associated with kratom use, medical providers should be knowledgeable of emerging substances and concurrent, sequential, or simultaneous use of other drugs which may impact healthcare recommendations and prescribing practices.

Methods

The objective of this narrative review was to elucidate selected health effects associated with using kratom-either alone or with other substances. Since scientifically controlled human subjects research on kratom use is still limited, relevant case reports were also described.

Results

Cardiovascular, gastrointestinal, neurological, and psychiatric effects associated with kratom use were especially notable, and in-utero exposure accompanied concern regarding a neonate's risk for developing neonatal abstinence syndrome. Our ability to identify and understand the role of this herb in kratom-associated fatalities is complicated since kratom is not routinely screened for in standard forensic toxicology. If a screening is performed, it is usually for the major alkaloid, mitragynine, as a surrogate for kratom use. In addition to lacking a standard practice of screening decedents for kratom alkaloids, the association between mortality and kratom use may be confounded by polysubstance use, adulteration of kratom products, and drug-herb interactions.

Conclusions

Increasing medical awareness of this herb is vital to ensuring prompt administration of best-practice medical advice or treatment for people seeking information related to kratom use or for patients experiencing an adverse health effect that may be associated with using or withdrawing from kratom. Knowledge gained from continued surveillance and study of kratom and its associated health effects may assist in guiding clinical decision-making and preventing development of adverse health effects among people using kratom.

Understanding Kratom Use: A Guide for Healthcare Providers

Kratom (Mitragyna speciosa Korth., Rubiaceae) is a plant native to Southeast Asia, where it has been used for centuries as a mild stimulant and as medicine for various ailments. More recently, as kratom has gained popularity in the West, United States federal agencies have raised concerns over its safety leading to criminalization in some states and cities. Some of these safety concerns have echoed across media and broad-based health websites and, in the absence of clinical trials to test kratom’s efficacy and safety, considerable confusion has arisen among healthcare providers. There is, however, a growing literature of peer-reviewed science that can inform healthcare providers so that they are better equipped to discuss kratom use with consumers and people considering kratom use within the context of their overall health and safety, while recognizing that neither kratom nor any of its constituent substances or metabolites have been approved as safe and effective for any disease. An especially important gap in safety-related science is the use of kratom in combination with physiologically active substances and medicines. With these caveats in mind we provide a comprehensive overview of the available science on kratom that has the potential to i clarity for healthcare providers and patients. We conclude by making recommendations for best practices in working with people who use kratom.

The Use of Kratom (Mitragyna speciosa Korth.) Among People Who Co-use Heroin and Methamphetamine in Malaysia

OBJECTIVES

Kratom (Mitragyna speciosa Korth.), an indigenous medicinal plant, has been widely used as a traditional remedy in Southeast Asia. However, its combined consumption with other substances has received scarce attention. This study investigates the use of kratom among adults with a history of using heroin and methamphetamine in Malaysia.

METHODS

A total of 332 patients who were mandated to undergo drug rehabilitation participated in this cross-sectional study. The study data were collected through face-to-face interviews using a semi-structured questionnaire.

RESULTS

The majority were males (95%, n = 314/332) and Malays (98%, n = 325/332) with a mean age of 32.3 years (SD = 9.16). Over two thirds of the respondents used kratom to alleviate heroin withdrawal symptoms and to reduce methamphetamine intake; 59% used it as a substitute for heroin and methamphetamine. A similar proportion used kratom to reduce heroin intake (58%), while only 15% used it for its euphoric effects. Multivariate analysis showed that previous attendees of government rehabilitation programs had lower odds of using kratom as a heroin substitute.

CONCLUSIONS

The potential of kratom to alleviate heroin withdrawal symptoms, and to reduce methamphetamine and heroin intake, among people who co-use heroin and methamphetamine warrants further research.

Kratom Abuse Potential 2021: An Updated Eight Factor Analysis

Drugs are regulated in the United States (US) by the Controlled Substances Act (CSA) if assessment of their abuse potential, including public health risks, show such control is warranted. An evaluation via the 8 factors of the CSA provides the comprehensive assessment required for permanent listing of new chemical entities and previously uncontrolled substances. Such an assessment was published for two kratom alkaloids in 2018 that the Food and Drug Administration (FDA) have identified as candidates for CSA listing: mitragynine (MG) and 7-hydroxymitragynine (7-OH-MG) (Henningfield et al., 2018a). That assessment concluded the abuse potential of MG was within the range of many other uncontrolled substances, that there was not evidence of an imminent risk to public health, and that a Schedule I listing (the only option for substances that are not FDA approved for therapeutic use such as kratom) carried public health risks including drug overdoses by people using kratom to abstain from opioids. The purpose of this review is to provide an updated abuse potential assessment reviewing greater than 100 studies published since January 1, 2018. These include studies of abuse potential and physical dependence/withdrawal in animals; in-vitro receptor binding; assessments of potential efficacy treating pain and substance use disorders; pharmacokinetic/pharmacodynamic studies with safety-related findings; clinical studies of long-term users with various physiological endpoints; and surveys of patterns and reasons for use and associated effects including dependence and withdrawal. Findings from these studies suggest that public health is better served by assuring continued access to kratom products by consumers and researchers. Currently, Kratom alkaloids and derivatives are in development as safer and/or more effective medicines for treating pain, substances use disorders, and mood disorders. Placing kratom in the CSA via scheduling would criminalize consumers and possession, seriously impede research, and can be predicted to have serious adverse public health consequences, including potentially thousands of drug overdose deaths. Therefore, CSA listing is not recommended. Regulation to minimize risks of contaminated, adulterated, and inappropriately marketed products is recommended.

Mitragyna Species as Pharmacological Agents: From Abuse to Promising Pharmaceutical Products

Mitragyna is a genus belonging to the Rubiaceae family and is a plant endemic to Asia and Africa. Traditionally, the plants of this genus were used by local people to treat some diseases from generation to generation. Mitragyna speciosa (Korth.) Havil. is a controversial plant from this genus, known under the trading name “kratom”, and contains more than 40 different types of alkaloids. Mitragynine and 7-hydroxymitragynine have agonist morphine-like effects on opioid receptors. Globally, Mitragyna plants have high economic value. However, regulations regarding the circulation and use of these commodities vary in several countries around the world. This review article aims to comprehensively examine Mitragyna plants (mainly M. speciosa) as potential pharmacological agents by looking at various aspects of the plants. A literature search was performed and information collected using electronic databases including Scopus, ScienceDirect, PubMed, directory open access journal (DOAJ), and Google Scholar in early 2020 to mid-2021. This narrative review highlights some aspects of this genus, including historical background and botanical origins, habitat, cultivation, its use in traditional medicine, phytochemistry, pharmacology and toxicity, abuse and addiction, legal issues, and the potential of Mitragyna species as pharmaceutical products.

Respiratory effects of oral mitragynine and oxycodone in a rodent model

RATIONALE

Kratom derives from Mitragyna speciosa (Korth.), a tropical tree in the genus Mitragyna (Rubiaceae) that also includes the coffee tree. Kratom leaf powders, tea-like decoctions, and commercial extracts are taken orally, primarily for health and well-being by millions of people globally. Others take kratom to eliminate opioid use for analgesia and manage opioid withdrawal and use disorder. There is debate over the possible respiratory depressant overdose risk of the primary active alkaloid, mitragynine, a partial μ-opioid receptor agonist, that does not signal through ß-arrestin, the primary opioid respiratory depressant pathway.

OBJECTIVES

Compare the respiratory effects of oral mitragynine to oral oxycodone in rats with the study design previously published by US Food and Drug Administration (FDA) scientists for evaluating the respiratory effects of opioids (Xu et al., Toxicol Rep 7:188-197, 2020).

METHODS

Blood gases, observable signs, and mitragynine pharmacokinetics were assessed for 12 h after 20, 40, 80, 240, and 400 mg/kg oral mitragynine isolate and 6.75, 60, and 150 mg/kg oral oxycodone hydrochloride.

FINDINGS

Oxycodone administration produced significant dose-related respiratory depressant effects and pronounced sedation with one death each at 60 and 150 mg/kg. Mitragynine did not yield significant dose-related respiratory depressant or life-threatening effects. Sedative-like effects, milder than produced by oxycodone, were evident at the highest mitragynine dose. Maximum oxycodone and mitragynine plasma concentrations were dose related.

CONCLUSIONS

Consistent with mitragynine's pharmacology that includes partial µ-opioid receptor agonism with little recruitment of the respiratory depressant activating β-arrestin pathway, mitragynine produced no evidence of respiratory depression at doses many times higher than known to be taken by humans.

Oxidative Metabolism as a Modulator of Kratom's Biological Actions

The leaves of Mitragyna speciosa (kratom), a plant native to Southeast Asia, are increasingly used as a pain reliever and for attenuation of opioid withdrawal symptoms. Using the tools of natural products chemistry, chemical synthesis, and pharmacology, we provide a detailed in vitro and in vivo pharmacological characterization of the alkaloids in kratom. We report that metabolism of kratom's major alkaloid, mitragynine, in mice leads to formation of (a) a potent mu opioid receptor agonist antinociceptive agent, 7-hydroxymitragynine, through a CYP3A-mediated pathway, which exhibits reinforcing properties, inhibition of gastrointestinal (GI) transit and reduced hyperlocomotion, (b) a multifunctional mu agonist/delta-kappa antagonist, mitragynine pseudoindoxyl, through a CYP3A-mediated skeletal rearrangement, displaying reduced hyperlocomotion, inhibition of GI transit and reinforcing properties, and (c) a potentially toxic metabolite, 3-dehydromitragynine, through a non-CYP oxidation pathway. Our results indicate that the oxidative metabolism of the mitragynine template beyond 7-hydroxymitragynine may have implications in its overall pharmacology in vivo.

Clinical Pharmacology of the Dietary Supplement, Kratom (Mitragyna speciosa)

Kratom (Mitragyna speciosa) consists of over 40 alkaloids with two of them, mitragynine (MG) and 7-OH-mitragynine (7-OH-MG) being the main psychoactive compounds. MG and 7-OH-MG each target opioid receptors and have been referred to as atypical opioids. They exert their pharmacologic effects on the μ, δ, and κ opioid receptors. In addition, they affect adrenergic, serotonergic, and dopaminergic pathways. Kratom has been touted as an inexpensive, legal alternative to standard opioid replacement therapy such as methadone and buprenorphine. Other uses for kratom include chronic pain, attaining a "legal high," and numerous CNS disorders including anxiety depression and post-traumatic stress disorder (PTSD). Kratom induces analgesia and mild euphoria with a lower risk of respiratory depression or adverse central nervous system effects compared to traditional opioid medications. Nonetheless, kratom has been associated with both physical and psychological dependence with some individuals experiencing classic opioid withdrawal symptoms upon abrupt cessation. Kratom use has been linked to serious adverse effects including liver toxicity, seizures, and death. These risks are often compounded by poly-substance abuse. Further, kratom may potentiate the toxicity of coadministered medications through modulation of cytochrome P450, P-glycoprotein, and uridine diphosphate glucuronosyltransferase enzymes (UGDT). In 2016 the U.S. Drug Enforcement Administration (DEA) took steps to classify kratom as a federal schedule 1 medication; however, due to public resistance, this plan was set aside. Until studies are conducted that define kratom's role in treating opioid withdrawal and/or other CNS conditions, kratom will likely remain available as a dietary supplement for the foreseeable future. This article is protected by copyright. All rights reserved.

Characterization of urinary protein profile in regular kratom (Mitragyna speciosa korth.) users in Malaysia

Mitragyna speciosa (Korth.) also known as kratom or ketum has been traditionally used for its diverse medicinal value in Southeast Asia. Despite of its therapeutic value, kratom's safety profile remains deficiently elucidated. Our study aims to characterize the urinary protein profile of regular kratom users to determine its toxic effects on renal functioning. A total of 171 respondents (comprising of n = 88 regular kratom users, and n = 83 healthy controls) were recruited for this study. Urine specimens were collected and analyzed using SDS-PAGE, followed by LC/MS/MS analysis. Our results show albumin is the primary, and most abundant form of protein excreted in kratom user's urine specimens (n = 60/64), indicating that kratom users are predisposed to proteinuria. Kratom users had an elevated urinary protein (with an intensity of 66.7 kDa band), and protein: creatinine ratio (PCR) concentrations relative to healthy controls. However, kratom user's urinary creatinine concentration was found to be in the normal range as the healthy control group. While, kratom users who tested positive for illicit drug use had an elevated urinary albumin concentration. Our preliminary findings indicate that regular consumption of freshly brewed kratom solution over a protracted period (for an average of eleven years) seems to induce proteinuria, suggestive of an early stage of kidney injury. Hence, further studies are urgently needed to confirm our findings, and establish kratom's renal impairing effects.

Pentylenetetrazol-like stimulus is not produced following naloxone-precipitated mitragynine withdrawal in rats

RATIONALE

Kratom (Mitragyna speciosa Korth), a native medicinal plant of Southeast Asia, is proposed to exhibit potential therapeutic value as an opioid substitute. However, studies of its negative emotional states resulting from withdrawal particularly of its main psychoactive compound, mitragynine (MG), are limited.

OBJECTIVES

Using the pentylenetetrazol (PTZ) discrimination assay, this study aims to investigate the effects of MG in responding to the PTZ stimulus and to assess the generalisation effects of withdrawal from MG to the PTZ stimulus.

METHODS

Rats (n = 20) were trained on a tandem (FR-10, VI-15) schedule of food reinforcement to press one lever after administration of the anxiogenic compound PTZ (16 mg/kg, i.p.) and an alternate lever after vehicle. Following acute tests, training was suspended, and rats were chronically treated with MG or morphine at 8-h intervals for 9 days and withdrawal was precipitated on the tenth day using naloxone (1 mg/kg, i.p.). The rats were tested for generalisation to PTZ at 2, 8 and 24 h after the last dose of MG or morphine administration.

RESULTS

Unlike morphine that produced dose-related PTZ-like stimulus, MG at 3, 10, 30 and 45 mg/kg doses showed no substitution to the PTZ discriminative stimulus. In contrast to morphine which produced a time-dependent generalisation to the PTZ stimulus, naloxone did not precipitate withdrawal effects in MG-treated rats as they selected the vehicle lever at three withdrawal time points.

CONCLUSION

These results demonstrate that MG produces a very different response to morphine withdrawal that is not associated with anxiogenic-like subjective symptoms. These characteristics of MG may provide further support for use as a novel pharmacotherapeutic intervention for managing opioid use disorder.

Herbal and dietary supplement induced liver injury: Highlights from the recent literature

Herbal-induced liver injury (HILI) is an important and increasingly concerning cause of liver toxicity, and this study presents recent updates to the literature. An extensive literature review was conducted encompassing September 2019 through March 2021. Studies with clinically significant findings were analyzed and included in this review. We emphasized those studies that provided a causality assessment methodology, such as Roussel Uclaf Causality Assessment Method scores. Our review includes reports of individual herbals, including Garcinia cambogia, green tea extract, kratom as well as classes such as performance enhancing supplements, Traditional Chinese medicine, Ayurvedic medicine and herbal contamination. Newly described herbals include ashwagandha, boldo, skyfruit, and 'Thermo gun'. Several studies discussing data from national registries, including the United States Drug-Induced Liver Injury (DILI) Network, Spanish DILI Registry, and Latin American DILI Network were incorporated. There has also been a continued interest in hepatoprotection, with promising use of herbals to counter hepatotoxicity from anti-tubercular medications. We also elucidated the current legal conversation surrounding use of herbals by presenting updates from the Federal Drug Administration. The highlights of the literature over the past year indicate interest in HILI that will continue as the supplement industry in the United States grows.

Kratom Use Within the Context of the Evolving Opioid Crisis and the COVID-19 Pandemic in the United States

Kratom (Mitragyna speciosa, Korth.) is an evergreen 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. Despite the long history of kratom use in Asia, it is only within the past 10-20 years that kratom has emerged as an important herbal agent in the United States, where it is being used for the self-treatment of pain, opioid withdrawal symptoms, and mood disorders. The increase in the use of kratom in the United States has coincided with the serious epidemic of opioid abuse and dependence. Since 2015, efforts to restrict access to prescription opioids have resulted in a marked increase in the use of "street" opioids such as heroin and illicit fentanyl. At the same time, many patients with chronic pain conditions or opioid use disorder have been denied access to appropriate medical help. The lack of access to care for patients with chronic pain and opioid use disorder has been magnified by the emergence of the COVID-19 pandemic. In this report, we highlight how these converging factors have led to a surge in interest in kratom as a potential harm reduction agent in the treatment of pain and opioid use disorder.