Safety of ibogaine administration in detoxification of opioid-dependent individuals: a descriptive open-label observational study

New Approach Methodologies (NAMs) for ad hoc human health risk assessment of food and non-food products - Proceedings of a workshop

RIVM convened a workshop on the use of New Approach Methodologies (NAMs) for the ad hoc human health risk assessment of food and non-food products. Central to the workshop were two case studies of marketed products with a potential health concern: the botanical Tabernanthe iboga which is used to facilitate mental or spiritual insight or to (illegally) treat drug addiction and is associated with cardiotoxicity, and dermal creams containing female sex hormones, intended for use by perimenopausal women to reduce menopause symptoms without medical supervision. The workshop participants recognized that data from NAM approaches added valuable information for the ad hoc risk assessment of these products, although the available approaches were inadequate to derive health-based guidance values. Recommendations were provided on how to further enhance and implement NAM approaches in regulatory risk assessment, specifying both scientific and technical aspects as well as stakeholder engagement aspects.

The pharmacokinetics and pharmacodynamics of ibogaine in opioid use disorder patients

OBJECTIVE

Ibogaine is a hallucinogenic drug that may be used to treat opioid use disorder (OUD). The relationships between pharmacokinetics (PKs) of ibogaine and its metabolites and their clinical effects on side effects and opioid withdrawal severity are unknown. We aimed to study these relationships in patients with OUD undergoing detoxification supported by ibogaine.

METHODS

The study was performed in 14 subjects with OUD. They received a single dose of 10mg/kg ibogaine hydrochloride. Plasma PKs of ibogaine, noribogaine, and noribogaine glucuronide were obtained during 24 h. Cytochrome P450 isoenzyme 2D6 (CYP2D6) genotyping was performed. The PKs were analyzed by means of nonlinear mixed effects modeling and related with corrected QT interval (QTc) prolongation, cerebellar ataxia, and opioid withdrawal severity.

RESULTS

The PK of ibogaine were highly variable and significantly correlated to CYP2D6 genotype (p < 0.001). The basic clearance of ibogaine (at a CYP2D6 activity score (AS) of 0) was 0.82 L/h. This increased with 30.7 L/h for every point of AS. The relation between ibogaine plasma concentrations and QTc was best described by a sigmoid Emax model. Spearman correlations were significant (p < 0.03) for ibogaine but not noribogaine with QTc (p = 0.109) and cerebellar effects (p = 0.668); neither correlated with the severity of opioid withdrawal symptoms.

CONCLUSIONS

The clearance of ibogaine is strongly related to CYPD2D6 genotype. Ibogaine cardiac side effects (QTc time) and cerebellar effects are most likely more driven by ibogaine rather than noribogaine. Future studies should aim at exploring lower doses and/or applying individualized dosing based on CYP2D6 genotype.

Catharanthine Modulates Mesolimbic Dopamine Transmission and Nicotine Psychomotor Effects via Inhibition of α6-Nicotinic Receptors and Dopamine Transporters

Iboga alkaloids, also known as coronaridine congeners, have shown promise in the treatment of alcohol and opioid use disorders. The objective of this study was to evaluate the effects of catharanthine and 18-methoxycoronaridine (18-MC) on dopamine (DA) transmission and cholinergic interneurons in the mesolimbic DA system, nicotine-induced locomotor activity, and nicotine-taking behavior. Utilizing ex vivo fast-scan cyclic voltammetry (FSCV) in the nucleus accumbens core of male mice, we found that catharanthine or 18-MC differentially inhibited evoked DA release. Catharanthine inhibition of evoked DA release was significantly reduced by both α4 and α6 nicotinic acetylcholine receptors (nAChRs) antagonists. Additionally, catharanthine substantially increased DA release more than vehicle during high-frequency stimulation, although less potently than an α4 nAChR antagonist, which confirms previous work with nAChR antagonists. Interestingly, while catharanthine slowed DA reuptake measured via FSCV ex vivo, it also increased extracellular DA in striatal dialysate from anesthetized mice in vivo in a dose-dependent manner. Superfusion of catharanthine or 18-MC inhibited the firing rate of striatal cholinergic interneurons in a concentration dependent manner, which are known to potently modulate presynaptic DA release. Catharanthine or 18-MC suppressed acetylcholine currents in oocytes expressing recombinant rat α6/α3β2β3 or α6/α3β4 nAChRs. In behavioral experiments using male Sprague-Dawley rats, systemic administration of catharanthine or 18-MC blocked nicotine enhancement of locomotor activity. Importantly, catharanthine attenuated nicotine self-administration in a dose-dependent manner while having no effect on food reinforcement. Lastly, administration of catharanthine and nicotine together greatly increased head twitch responses, indicating a potential synergistic hallucinogenic effect. These findings demonstrate that catharanthine and 18-MC have similar, but not identical effects on striatal DA dynamics, striatal cholinergic interneuron activity and nicotine psychomotor effects.

A natural small molecule aspidosperma-type alkaloid, hecubine, as a new TREM2 activator for alleviating lipopolysaccharide-induced neuroinflammation in vitro and in vivo

Neuroinflammation and oxidative stress play a crucial role in the pathogenesis of neurodegenerative diseases, including Alzheimer's disease. The triggering receptor expressed on myeloid cells 2 (TREM2), highly expressed by microglia in the central nervous system (CNS), can modulate neuroinflammatory responses. Currently, there are no approved drugs specifically targeting TREM2 for CNS diseases. Aspidosperma alkaloids have shown potential as anti-inflammatory and neuroprotective agents. This study aimed to elucidate the potential therapeutic effect of Hecubine, a natural aspidosperma-type alkaloid, as a TREM2 activator in lipopolysaccharide (LPS)-stimulated neuroinflammation in in vitro and in vivo models. In this study, molecular docking and cellular thermal shift assay (CTSA) were employed to investigate the interaction between Hecubine and TREM2. Enzyme-linked immunosorbent assay (ELISA), quantitative PCR, immunofluorescence, Western blotting, and shRNA gene knockdown were used to assess the anti-neuroinflammatory and antioxidant effects of Hecubine in microglial cells and zebrafish. Our results revealed that Hecubine directly interacted with TREM2, leading to its activation. Knockdown of TREM2 mRNA expression significantly abolished the anti-inflammatory and antioxidant effects of Hecubine on LPS-stimulated proinflammatory mediators (NO, TNF-α, IL-6, and IL-1β) and oxidative stress in microglia cells. Furthermore, Hecubine upregulated Nrf2 expression levels while downregulating TLR4 signaling expression levels both in vivo and in vitro. Silencing TREM2 upregulated TLR4 and downregulated Nrf2 signaling pathways, mimicking the effect of Hecubine, further supporting TREM2 as the drug target by which Hecubine inhibits neuroinflammation. In conclusion, this is the first study to identify a small molecule, namely Hecubine directly targeting TREM2 to mediate anti-neuroinflammation and anti-oxidative effects, which serves as a potential therapeutic agent for the treatment of neural inflammation-associated CNS diseases.

Psychedelic Therapy: A Primer for Primary Care Clinicians-Ibogaine

BACKGROUND

Ibogaine is a plant-derived alkaloid that has been used for thousands of years in rites of passage and spiritual ceremonies in West-Central Africa. In the West, it has primarily been used and studied for its anti-addictive properties and more recently for other neuropsychiatric indications, including post-traumatic stress disorder, depression, anxiety, and traumatic brain injury.

AREAS OF UNCERTAINTY

Ibogaine requires careful patient screening and monitoring because of significant safety issues. There is potential for cardiotoxicity (prolonged QT interval); without rigorous screening, fatal arrhythmias may occur. However, preliminary research suggests that co-administration of ibogaine with magnesium may mitigate cardiotoxicity. Additionally, ibogaine may have dangerous interactions with opiates, so patients who receive ibogaine treatment for opioid use disorder must withdraw from long-acting opioids. Other potential concerning effects of ibogaine include rare incidences of mania or psychosis. Anticipated transient effects during ibogaine treatment can include ataxia, tremors, and gastrointestinal symptoms.

THERAPEUTIC ADVANCES

Robust effects after a single treatment with ibogaine have been reported. In open-label and randomized controlled trials (RCTs), ibogaine reduces heroin and opioid cravings by upwards of 50%, up to 24 weeks after the treatment. An observational study of 30 Special Operations Forces veterans with mild traumatic brain injury reported that 86% were in remission from post-traumatic stress disorder, 83% from depression, and 83% from anxiety, one month after a single-dose ibogaine treatment.

LIMITATIONS

Although there are several observational and open-label studies, there is only a single double-blind, placebo-controlled RCT on ibogaine. More RCTs with large sample sizes must be conducted to support ibogaine's safety and efficacy.

CONCLUSIONS

Given the promising preliminary findings, ibogaine could potentially fill a much-needed gap in treatments for challenging conditions, including opioid dependence. Ibogaine's remarkable effects in traditionally treatment-resistant, combat-exposed individuals hints at its potential in broader populations with physical and psychological trauma.

A transcriptomic analysis in mice following a single dose of ibogaine identifies new potential therapeutic targets

Ibogaine (IBO) is an atypical psychedelic with a complex mechanism of action. To date, the mechanisms that may underlie its anti-addictive effects are still not defined. This study aims to identify changes in gene expression induced by a single oral dose of IBO in the cortex of mice by means of a transcriptomic analysis for the first time. Our results showed significant alterations in gene expression in mouse frontal cortex samples 4 h after a single oral dose of IBO. Specifically, genes involved in hormonal pathways and synaptogenesis exhibited upregulation, while genes associated with apoptotic processes and endosomal transports showed downregulation. The findings were further corroborated through quantitative polymerase chain reaction (qPCR) analysis. However, the validation of gene expression related to hormonal pathways did not entirely align with the transcriptomic analysis results, possibly due to the brain region from which tissue was collected. Sex differences were observed, with female mice displaying more pronounced alterations in gene expression after IBO treatment. High variability was observed across individual animals. However, this study represents a significant advancement in comprehending IBO's molecular actions. The findings highlight the influence of IBO on gene expression, particularly on hormonal pathways, synaptogenesis, apoptotic processes, and endosomal transports. The identification of sex differences underscores the importance of considering sex as a potential factor influencing IBO's effects. Further research to assess different time points after IBO exposure is warranted.

Psychedelic therapies reconsidered: compounds, clinical indications, and cautious optimism

The clinical investigation of psychedelic medicines has blossomed over the last 5 years. Data from a Phase 3 industry trial and a multicenter Phase 2 industry trial, in addition to multiple early phase investigator-initiated and industry trials, have now been published in peer-reviewed journals. This narrative review summarizes both the recent data and the current clinical trials that are being conducted with various classes of "psyche-manifesting" substances, which may prove beneficial in the treatment of a broad range of conditions. Methodological considerations, unique challenges, and next steps for research are discussed in keeping with the uniquely "experiential" nature of these therapies.

Main targets of ibogaine and noribogaine associated with its putative anti-addictive effects: A mechanistic overview

BACKGROUND

There is a growing interest in studying ibogaine (IBO) as a potential treatment for substance use disorders (SUDs). However, its clinical use has been hindered for mainly two reasons: First, the lack of randomized, controlled studies informing about its safety and efficacy. And second, IBO's mechanisms of action remain obscure. It has been challenging to elucidate a predominant mechanism of action responsible for its anti-addictive effects.

OBJECTIVE

To describe the main targets of IBO and its main metabolite, noribogaine (NOR), in relation to their putative anti-addictive effects, reviewing the updated literature available.

METHODS

A comprehensive search involving MEDLINE and Google Scholar was undertaken, selecting papers published until July 2022. The inclusion criteria were both theoretical and experimental studies about the pharmacology of IBO. Additional publications were identified in the references of the initial papers.

RESULTS

IBO and its main metabolite, NOR, can modulate several targets associated with SUDs. Instead of identifying key targets, the action of IBO should be understood as a complex modulation of multiple receptor systems, leading to potential synergies. The elucidation of IBO's pharmacology could be enhanced through the application of methodologies rooted in the polypharmacology paradigm. Such approaches possess the capability to describe multifaceted patterns within multi-target drugs.

CONCLUSION

IBO displays complex effects through multiple targets. The information detailed here should guide future research on both mechanistic and therapeutic studies.

Endogenous opiates and behavior: 2022

This paper is the forty-fifth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2022 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Identifying setting factors associated with improved ibogaine safety: a systematic review of clinical studies

Ibogaine is a psychoactive alkaloid derived from the west-African shrub Tabernanthe iboga. Western cultures are increasing the interest for the substance due to its claimed anti addictive properties, although the evidence supporting this effect is still preliminary. The use of ibogaine often occurs with no medical supervision in uncontrolled settings, and its use has been associated with several reports of severe adverse events. This review aims to evaluate the clinical studies of ibogaine, with a focus on administration settings, to elucidate specific criteria that may promote safer contexts for ibogaine use. A systematic review of the literature was conducted based on PRISMA guidelines. PubMed, Scielo, ClinicalTrials.gov and Core.ac.uk electronic databases were searched, and clinical studies published until November 17, 2022, were retrieved. The final synthesis included 12 sources. Information about general characteristics of the studies, adverse effects, screening of participants and setting characteristics were summarized and discussed. It is concluded that the use of controlled settings, supported by trained professionals and equipment allowing for rigorous medical, psychiatric, and cardiac monitoring, are essential to promote the safety of patients receiving ibogaine.

Hallucinogenic potential: a review of psychoplastogens for the treatment of opioid use disorder

The United States is entering its fourth decade of the opioid epidemic with no clear end in sight. At the center of the epidemic is an increase in opioid use disorder (OUD), a complex condition encompassing physical addiction, psychological comorbidities, and socioeconomic and legal travails associated with the misuse and abuse of opioids. Existing behavioral and medication-assisted therapies show limited efficacy as they are hampered by lack of access, strict regimens, and failure to fully address the non-pharmacological aspects of the disease. A growing body of research has indicated the potential of hallucinogens to efficaciously and expeditiously treat addictions, including OUD, by a novel combination of pharmacology, neuroplasticity, and psychological mechanisms. Nonetheless, research into these compounds has been hindered due to legal, social, and safety concerns. This review will examine the preclinical and clinical evidence that psychoplastogens, such as ibogaine, ketamine, and classic psychedelics, may offer a unique, holistic alternative for the treatment of OUD while acknowledging that further research is needed to establish long-term efficacy along with proper safety and ethical guidelines.

Developing non-opioid therapeutics to alleviate pain among persons with opioid use disorder: a review of the human evidence

The opioid crisis remains a major public health concern, causing significant morbidity and mortality worldwide. Pain is frequently observed among individuals with opioid use disorder (OUD), and the current opioid agonist therapies (OAT) have limited efficacy in addressing the pain needs of this population. We reviewed the most promising non-opioid analgesic therapies for opioid-dependent individuals synthesising data from randomised controlled trials in the Medline database from December 2022 to March 2023. Ketamine, gabapentin, serotoninergic antidepressants, and GABAergic drugs were found to be the most extensively studied non-opioid analgesics with positive results. Additionally, we explored the potential of cannabinoids, glial activation inhibitors, psychedelics, cholecystokinin antagonists, alpha-2 adrenergic agonists, and cholinergic drugs. Methodological improvements are required to advance the development of novel analgesic strategies and establish their safety profile for opioid-dependent populations. We highlight the need for greater integration of experimental pain methods and abuse liability assessments, more granular assessments of prior opioid exposure, greater uniformity of pain types within study samples, and a particular focus on individuals with OUD receiving OAT. Finally, future research should investigate pharmacokinetic interactions between OAT and various non-opioid analgesics and perform reverse translation basic experiments, particularly with methadone and buprenorphine, which remain the standard OUD treatment.

IUPHAR - invited review - Ibogaine - A legacy within the current renaissance of psychedelic therapy

Ibogaine is a powerful psychoactive substance that not only alters perception, mood and affect, but also stops addictive behaviors. Ibogaine has a very long history of ethnobotanical use in low doses to combat fatigue, hunger and thirst and, in high doses as a sacrament in African ritual contexts. In the 1960's, American and European self-help groups provided public testimonials that a single dose of ibogaine alleviated drug craving, opioid withdrawal symptoms, and prevented relapse for weeks, months and sometimes years. Ibogaine is rapidly demethylated by first-pass metabolism to a long-acting metabolite noribogaine. Ibogaine and its metabolite interact with two or more CNS targets simultaneously and both drugs have demonstrated predictive validity in animal models of addiction. Online forums endorse the benefits of ibogaine as an "addiction interrupter" and present-day estimates suggest that more than ten thousand people have sought treatment in countries where the drug is unregulated. Open label pilot studies of ibogaine-assisted drug detoxification have shown positive benefit in treating addiction. Ibogaine, granted regulatory approval for human testing in a Phase 1/2a clinical trial, joins the current landscape of psychedelic medicines in clinical development.

Ibogaine/Noribogaine in the Treatment of Substance Use Disorders: A Systematic Review of the Current Literature

BACKGROUND

Ibogaine and noribogaine are psychedelic substances with dissociative properties naturally occurring in plants of the Apocynaceae family. Research has shown their efficacy in treating substance use disorders (SUD), particularly in opiate detoxification, but their efficacy and toxicity are still unclear.

OBJECTIVE

This review aims to assess the anti-addictive role of ibogaine and evaluate its side effects.

METHODS

A systematic literature review was conducted on the 29th of November 2021 using PubMed, Scopus and Web of Science databases through the following search strategy: ("Ibogaine" OR "Noribogaine") AND ("SUD" OR "substance use disorder" OR "craving" OR "abstinence" OR "withdrawal" OR "addiction" OR "detoxification") NOT animal NOT review NOT "vitro." The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was followed for data gathering purposes. Research methods were registered on PROSPERO (CRD42021287034).

RESULTS

Thirty-one articles were selected for the systematic revision, and two were considered for analysis. The results were organised according to the type of study: case reports/case series, randomised- controlled trials (RCTs), open-label, survey and observational studies. The main outcomes were related to the anti-addictive effect of ibogaine and its cardiac toxicity. A meta-analysis of side effects was conducted using RevMan 5.4 software, showing a significant risk of developing headaches after ibogaine/noribogaine treatment.

CONCLUSION

The results show some efficacy of ibogaine in the treatment of SUDs, but its cardiotoxicity and mortality are worrying. Further studies are needed to assess its therapeutic efficacy and actual safety.

Psychedelic Therapies at the Crossroads of Trauma and Substance Use: Historical Perspectives and Future Directions, Taking a Lead From New Mexico

Post-traumatic stress disorder (PTSD), a common condition with potentially devastating individual, family, and societal consequences, is highly associated with substance use disorders (SUDs). The association between PTSD and SUD is complex and may involve adverse childhood experiences (ACEs), historical and multi-generational traumas, and social determinants of health as well as cultural and spiritual contexts. Current psychosocial and pharmacological treatments for PTSD are only modestly effective, and there is a need for more research on therapeutic interventions for co-occurring PTSD and SUD, including whether to provide integrated or sequential treatments. There is a current resurgence of interest in psychedelics as potential treatment augmentation for PTSD and SUDs with an appreciation of the risks in this target population. This paper reviews the historical perspective of psychedelic research and practices, as well as the intersection of historical trauma, ACEs, PTSD, and SUDs through the lens of New Mexico. New Mexico is a state with high populations of Indigenous and Hispanic peoples as well as high rates of trauma, PTSD, and SUDs. Researchers in New Mexico have been leaders in psychedelic research. Future directions for psychedelic researchers to consider are discussed, including the importance of community-based participatory approaches that are more inclusive and respectful of Indigenous and other minority communities.