"I just wanted to tell you that loperamide WILL WORK": a web-based study of extra-medical use of loperamide

Evaluation of the Effect of Loperamide on the Cardiac Repolarization Interval Using Exposure-Response Analysis

This analysis assessed the relationship between the plasma concentrations of loperamide and its N-desmethyl loperamide meta- bolite (M1) and the potential QT interval prolongation at therapeutic and supratherapeutic doses. The exposure-response analysis was performed using the data from healthy adults participating in a randomized, double-blind, single-dose, four-way (placebo; loperamide 8 mg [therapeutic]; loperamide 48 mg [supratherapeutic]; moxifloxacin 400 mg [positive control]) crossover study. The electrocardiographic measurements extracted from 12-lead digital Holter recordings were time-matched to pharmacokinetic sampling of loperamide/M1. The primary response variable was placebo-adjusted change from baseline in Fridericia-corrected QT interval (ΔΔQTcF); the exposure variable was loperamide and/or M1 concentration. A total of 53 participants with 1408 time-matched pharmacokinetic and ΔΔQTcF measurements was analyzed. Hysteresis between both loperamide and M1 concentrations and ΔΔQTcF was observed with supratherapeutic dose. The pre-specified linear concentration-ΔΔQTcF relationship was driven by M1 concentrations in the effect compartment. The model-predicted mean ΔΔQTcF at the geometric mean of the maximum concentration in the effect compartment was -0.526 msec (90% CI, -1.51 to 0.462) following 8-mg dose (2.1 ng/mL) and 6.06 msec (90% CI, 3.86-8.27) following 48-mg dose (14.2 ng/mL). The upper bound of two-sided 90% CI was < 10 msec for both doses. The sensitivity analysis considering loperamide concentrations in the effect compartment instead of M1 as input for the concentration-ΔΔQTcF analysis confirmed these findings. The data showed that loperamide or M1 does not have an effect on cardiac repolarization that exceeds the threshold of regulatory concern in healthy participants at doses of 8 and 48 mg.

An Analysis of the Prevalence and Trends in Drug-Related Lyrics on Twitter (X): Quantitative Approach

BACKGROUND

The pervasiveness of drug culture has become evident in popular music and social media. Previous research has examined drug abuse content in both social media and popular music; however, to our knowledge, the intersection of drug abuse content in these 2 domains has not been explored. To address the ongoing drug epidemic, we analyzed drug-related content on Twitter (subsequently rebranded X), with a specific focus on lyrics. Our study provides a novel finding on the prevalence of drug abuse by defining a new subcategory of X content: "tweets that reference established drug lyrics."

OBJECTIVE

We aim to investigate drug trends in popular music on X, identify and classify popular drugs, and analyze related artists' gender, genre, and popularity. Based on the collected data, our goal is to create a prediction model for future drug trends and gain a deeper understanding of the characteristics of users who cite drug lyrics on X.

METHODS

X data were collected from 2015 to 2017 through the X streaming application programming interface (API). Drug lyrics were obtained from the Genius lyrics database using the Genius API based on drug keywords. The Smith-Waterman text-matching algorithm is used to detect the drug lyrics in posts. We identified famous drugs in lyrics that were posted. Consequently, the analysis was extended to related artists, songs, genres, and popularity on X. The frequency of drug-related lyrics on X was aggregated into a time-series, which was then used to create prediction models using linear regression, Facebook Prophet, and NIXTLA TimeGPT-1. In addition, we analyzed the number of followers of users posting drug-related lyrics to explore user characteristics.

RESULTS

We analyzed over 1.97 billion publicly available posts from 2015 to 2017, identifying more than 157 million that matched drug-related keywords. Of these, 150,746 posts referenced drug-related lyrics. Cannabinoids, opioids, stimulants, and hallucinogens were the most cited drugs in lyrics on X. Rap and hip-hop dominated, with 91.98% of drug-related lyrics from these genres and 84.21% performed by male artists. Predictions from all 3 models, linear regression, Facebook Prophet, and NIXTLA TimeGPT-1, indicate a slight decline in the prevalence of drug-related lyrics on X over time.

CONCLUSIONS

Our study revealed 2 significant findings. First, we identified a previously unexamined subset of drug-related content on X: drug lyrics, which could play a critical role in models predicting the surge in drug-related incidents. Second, we demonstrated the use of cutting-edge time-series forecasting tools, including Facebook Prophet and NIXTLA TimeGPT-1, in accurately predicting these trends. These insights contribute to our understanding of how social media shapes public behavior and sentiment toward drug use.

Loperamide positive deaths in Sweden 2012-2022 and Finland 2017-2022: Fatal loperamide intoxication exclusively for Sweden

Loperamide, a potent μ-opioid receptor agonist used as an antidiarrheal drug, exhibits increased bioavailability at supratherapeutic doses, causing potential central nervous system effects. Its misuse for opioid withdrawal relief and euphoria can lead to dangerously elevated blood levels, causing severe cardiac dysrhythmias and death. This study aimed to compare loperamide positive autopsy cases in Sweden and Finland after the introduction of postmortem toxicological analysis of loperamide, focusing on loperamide's role in fatalities and identifying common characteristics among those affected. All cases with detected loperamide in femoral blood at forensic autopsies in Sweden (2012-2022) and Finland (2017-2022) were included. In Sweden, loperamide was detected in 126 individuals, and in Finland, in 111 individuals. The incidence of individuals positive for loperamide in postmortem femoral blood increased steadily over the study duration in both Sweden and Finland. Loperamide related fatalities were observed exclusively in Sweden (n=80), predominantly involving younger males with histories of substance abuse, typically classified as accidental deaths. The group of loperamide nonrelated deaths in Sweden mirrored the entirety of cases in Finland. The concentration of loperamide in postmortem femoral blood was significantly higher in cases where loperamide was considered the cause of death (median 0.140 μg/g) compared to cases where loperamide contributed (median 0.080 μg/g), as well as in deaths unrelated to loperamide in both countries (Sweden: median 0.029 μg/g; Finland: median 0.010 μg/ml). The high limit of quantification for loperamide in Sweden may underestimate therapeutic users in epidemiological assessments. This study underscores the absence of loperamide misuse in Finland and indicates a rising trend of loperamide abuse in Sweden.

Loperamide-Induced Torsades de Pointes

Loperamide is a readily available, over-the-counter medication used to treat diarrhea. At therapeutic doses, loperamide exerts its effects mainly on the intestinal opioid receptors with minimal psychoactive effects; however, at supratherapeutic doses, it reaches central opioid receptors. With tighter regulations on opioid prescriptions, loperamide has emerged as a popular drug of abuse among opioid users. At supratherapeutic doses, loperamide can cause severe cardiac toxicity, resulting in wide QRS rhythms, severe bradycardia, prolonged QTc, polymorphic ventricular tachycardia, and cardiac arrest. We present the case of a 27-year-old female with a history of heroin abuse who suffered torsades de pointes resulting in cardiac arrest in the setting of a loperamide overdose.

The Potential Mechanisms behind Loperamide-Induced Cardiac Arrhythmias Associated with Human Abuse and Extreme Overdose

Loperamide has been a safe and effective treatment for diarrhea for many years. However, many cases of cardiotoxicity with intentional abuse of loperamide ingestion have recently been reported. We evaluated loperamide in in vitro and in vivo cardiac safety models to understand the mechanisms for this cardiotoxicity. Loperamide slowed conduction (QRS-duration) starting at 0.3 µM [~1200-fold (×) its human Free Therapeutic Plasma Concentration; FTPC] and reduced the QT-interval and caused cardiac arrhythmias starting at 3 µM (~12,000× FTPC) in an isolated rabbit ventricular-wedge model. Loperamide also slowed conduction and elicited Type II/III A-V block in anesthetized guinea pigs at overdose exposures of 879× and 3802× FTPC. In ion-channel studies, loperamide inhibited hERG (IKr), INa, and ICa currents with IC50 values of 0.390 µM, 0.526 µM, and 4.091 µM, respectively (i.e., >1560× FTPC). Additionally, in silico trials in human ventricular action potential models based on these IC50s confirmed that loperamide has large safety margins at therapeutic exposures (≤600× FTPC) and confirmed repolarization abnormalities in the case of extreme doses of loperamide. The studies confirmed the large safety margin for the therapeutic use of loperamide but revealed that at the extreme exposure levels observed in human overdose, loperamide can cause a combination of conduction slowing and alterations in repolarization time, resulting in cardiac proarrhythmia. Loperamide's inhibition of the INa channel and hERG-mediated IKr are the most likely basis for this cardiac electrophysiological toxicity at overdose exposures. The cardiac toxic effects of loperamide at the overdoses could be aggravated by co-medication with other drug(s) causing ion channel inhibition.

Perspectives of and Experience toward the Abuse of Antidiarrheal Drug (Loperamide) among Community Pharmacists: A Cross-Sectional Study

This study aimed to assess the ability of community pharmacists to recognize cases of loperamide abuse at the point of sale, their perspective of and experience toward potential abuse cases.

METHODS

A cross-sectional study was conducted in Jordan, using a self-administered online questionnaire. The questionnaire consisted of three main parts: demographics, the experience of pharmacists with abusers' behavior, as well as their perspectives toward loperamide abuse.

RESULTS

A total of 250 community pharmacists completed the survey, 54% (135) of which were female. Almost one-third (33.2%; 83) of the participants reported exposure to suspected cases of loperamide abuse during the last six months. Pharmacists declared that most of the suspected loperamide abusers were male (60.2%), of middle-low socioeconomic status (69.9%), and between 20 and 30 years of age (57.8%). The largest quantity (packs) of loperamide requested by a single patient was around 33.2 ± 14.9 at once. As reported by pharmacists, the suspected reasons behind loperamide abuse included 50% seeking euphoria, 17% relieving anxiety, and 33% controlling addiction (weaning off other opioids). The multivariate logistic regression analysis demonstrated a significant correlation between the male sex (OR = 1.2, 95% CI 0.12-1.59), pharmacy location in the center of Jordan (OR = 21.2, 95% CI 2.45-183.59), late-night working shift (Shift C, OR = 1.29, 95% CI 0.12-2.08), and abuse to loperamide during the last six months.

CONCLUSIONS

This study sheds light on loperamide abuse potentials, which could be influenced by different sociodemographic characteristics. Accordingly, close monitoring and thorough tackling of the abuse practices are mandated through an increase in educational and awareness campaigns about proper medication use.

An Opioid Hiding in Plain Sight: Loperamide-Induced False-Positive Fentanyl and Buprenorphine Immunoassay Results

BACKGROUND

Loperamide (Imodium®), a commonly used anti-diarrheal, is a mu opioid receptor agonist that, like all opioids, reduces gastrointestinal tract peristalsis. Loperamide is considered to have low abuse potential as it does not produce an analgesic or euphoric effect due to low bioavailability and first-pass metabolism. However, reports of individuals misusing loperamide through the use of super-therapeutic doses, alone or in combination with P-glycoprotein and/or CYP450 enzyme inhibitors, is increasing. We hypothesized that loperamide could potentially cross-react with laboratory immunoassay drug screens.

METHODS

Drug-free urine was spiked with loperamide or its principal metabolite, N-desmethyl loperamide (dLop), and assayed on multiple fentanyl and buprenorphine assays. Fentanyl immunoassay screen-positive results at one institution were examined by high-resolution mass spectrometry (MS) for the presence of loperamide and quantified by liquid chromatography- tandem MS when positive.

RESULTS

Loperamide produced positive results on the Thermo DRI Fentanyl and Immunalysis Fentanyl assays at concentrations greater than 5.72 mg/L and 23.7 mg/L. dLop generated positive results for the Thermo DRI and Immunalysis fentanyl assays at concentrations exceeding 6.9 mg/L and 35.7 mg/L. dLop also produced positive buprenorphine results on the Thermo CEDIA buprenorphine assay at concentrations exceeding 12.2 mg/L. High-resolution MS analysis of 225 fentanyl immunoassay positives (Thermo DRI) yielded 5 specimens containing loperamide and/or dLop, 4 of which contained measurable quantities of fentanyl in addition to loperamide/dLop.

CONCLUSIONS

Laboratories using these assays should be aware of the potential for false-positive screening results due to the presence of high concentrations of loperamide and its metabolite dLop.

Loperamide-Induced Ventricular Tachycardia Storm

Loperamide is an over-the-counter antilaxative medication with minor opioid properties. For this reason, it has recently become a drug of concern for the Food and Drug Administration due to its potential for abuse. In addition, further apprehension pertaining to its over-the-counter availability has developed due to the recent increase in reported cases of loperamide overdose or prolonged use leading to arrhythmias. We describe a rare case of loperamide-induced ventricular tachycardia storm.

Loperamide-induced ventricular tachycardia storm

Loperamide is an over-the-counter, peripherally-acting, μ-opioid receptor agonist commonly used in the treatment of diarrhoea. It has increasingly been recognised as a potential drug of misuse, having previously been thought to have low potential for abuse owing to its low bioavailability and poor penetration of the central nervous system. High doses can result in life-threatening cardiac-toxicity. We present a case of a young woman who had been self-treating her depression with high doses of loperamide for one year, who then presented to hospital with syncope secondary to ventricular tachycardia (VT). While in the emergency department (ED) the patient had monomorphic pulseless VT requiring electrical cardioversion multiple times. Transfer to a tertiary cardiac centre was immediately arranged after she was stabilised and intubated. This complicated the diagnostic process as a thorough history could not be obtained on arrival to the tertiary centre, which meant the loperamide misuse only came to light multiple days into admission, after the patient was extubated. The final diagnosis of loperamide-induced secondary long-QT syndrome was made and the patient made a full recovery.

DARK Classics in Chemical Neuroscience: Loperamide

Loperamide, a popular and inexpensive over-the-counter antidiarrheal medicine, is a potent μ-opioid receptor agonist approved by the U.S. Food and Drug Administration (FDA). It has been on the market since 1976 and is relatively safe with no central nervous system-related side effects when used for a short period of time at the recommended therapeutic dose (2-8 mg/day). In recent years, loperamide has become notoriously known as the "poor man's methadone" for people with substance dependence due to the increase in loperamide overdoses from self-administered medication to treat opioid withdrawal symptoms. As a result, in 2018, the FDA decided to limit the available packaged dose of loperamide to stop prominent abuse. This review provides the synthesis and chemical properties of loperamide as well as the pharmacology and adverse effects of its use and the social effects of such abuse.

Cardiovascular Complications of Opioid Use: JACC State-of-the-Art Review

Opioids are the most potent of all analgesics. Although traditionally used solely for acute self-limited conditions and palliation of severe cancer-associated pain, a movement to promote subjective pain (scale, 0 to 10) to the status of a "fifth vital sign" bolstered widespread prescribing for chronic, noncancer pain. This, coupled with rising misuse, initiated a surge in unintentional deaths, increased drug-associated acute coronary syndrome, and endocarditis. In response, the American College of Cardiology issued a call to action for cardiovascular care teams. Opioid toxicity is primarily mediated via potent μ-receptor agonism resulting in ventilatory depression. However, both overdose and opioid withdrawal can trigger major adverse cardiovascular events resulting from hemodynamic, vascular, and proarrhythmic/electrophysiological consequences. Although natural opioid analogues are devoid of repolarization effects, synthetic agents may be proarrhythmic. This perspective explores cardiovascular consequences of opioids, the contributions of off-target electrophysiologic properties to mortality, and provides practical safety recommendations.

Loperamide-induced cardiotoxicity: a case overlooked?

A young man presented to the emergency department with seizures and recurrent episodes of polymorphic ventricular tachycardia (PMVT)/torsades de pointes (TdP) requiring cardioversion and administration of intravenous magnesium. A battery of tests performed to identify a cause for his arrhythmias and seizures were all normal. A revisit of history with family revealed he had consumed over 100 tablets/day of loperamide for the past 1 year. A prolonged QT interval on his ECG raised concerns for long QT syndrome (LQTS) (congenital or acquired). Our patient was suspected to have loperamide-induced cardiotoxicity. TdP is a specific PMVT that occurs with a prolonged QT interval and is usually drug-induced. Less frequently, congenital LQTS may be implicated. With supportive care, including mechanical ventilation, vasopressors and temporary transvenous overdrive pacing, our patient recovered completely. We describe the importance of a systematic and time-sensitive approach to diagnosing critical illness. Loperamide overdose may cause QT prolongation, life-threatening arrhythmias/cardiogenic shock, or cardiac arrest. Seizures/epilepsy may also be a manifestation in young patients. There is a substantial need to revisit the safety of over-the-counter medications and increasing awareness of manifestations of drug overdose.

A Case Report of Torsade de Pointes and Brugada Pattern Associated with Loperamide Misuse and Supratherapeutic Loperamide Concentrations

BACKGROUND

Loperamide, commonly sold under the brand name Imodium® (Johnson & Johnson, Fort Washington, PA), is a widely available, over-the-counter antidiarrheal medication that possesses µ-opioid agonist properties and can have catastrophic cardiac events when misused or abused. Since the start of the opioid epidemic in the United States, there has been an increasing number of case reports and deaths linking loperamide abuse with cardiac events such as torsades de pointes (TdP) and Brugada syndrome.

CASE REPORT

This case report presents a 22-year-old man who presented in cardiac arrest from polymorphic ventricular tachycardia consistent with TdP and a Type 1 Brugada pattern after intentional loperamide abuse. We discuss this patient's management and the proposed pathophysiology of these two cardiotoxicities, of which, to our knowledge, no previously published case report has displayed both in the same patient after a supratherapeutic loperamide ingestion. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: As the prevalence of opioid dependency and misuse has increased, so, too, has the misuse of un-scheduled medications such as loperamide to achieve central nervous system opioid effects. It is important for the emergency physician to know about and understand loperamide-associated cardiotoxicities such as prolongation of the QRS, unmasking of Brugada patterns, QT prolongation, or ventricular dysrhythmias such as TdP to be able to recognize and treat it.

Mining social media for prescription medication abuse monitoring: a review and proposal for a data-centric framework

Objective

Prescription medication (PM) misuse and abuse is a major health problem globally, and a number of recent studies have focused on exploring social media as a resource for monitoring nonmedical PM use. Our objectives are to present a methodological review of social media–based PM abuse or misuse monitoring studies, and to propose a potential generalizable, data-centric processing pipeline for the curation of data from this resource.

Materials and Methods

We identified studies involving social media, PMs, and misuse or abuse (inclusion criteria) from Medline, Embase, Scopus, Web of Science, and Google Scholar. We categorized studies based on multiple characteristics including but not limited to data size; social media source(s); medications studied; and primary objectives, methods, and findings.

Results

A total of 39 studies met our inclusion criteria, with 31 (∼79.5%) published since 2015. Twitter has been the most popular resource, with Reddit and Instagram gaining popularity recently. Early studies focused mostly on manual, qualitative analyses, with a growing trend toward the use of data-centric methods involving natural language processing and machine learning.

Discussion

There is a paucity of standardized, data-centric frameworks for curating social media data for task-specific analyses and near real-time surveillance of nonmedical PM use. Many existing studies do not quantify human agreements for manual annotation tasks or take into account the presence of noise in data.

Conclusion

The development of reproducible and standardized data-centric frameworks that build on the current state-of-the-art methods in data and text mining may enable effective utilization of social media data for understanding and monitoring nonmedical PM use.

"It's Crazy What Meth Can Help You Do": Lay Beliefs, Practices, and Experiences of Using Methamphetamine to Self-Treat Symptoms of Opioid Withdrawal

BACKGROUND

Across the U.S., methamphetamine use is expanding among people who use illicit opioids (PWUIO). Motives for methamphetamine use must be contextualized within the experiences of PWUIO, who may use methamphetamine not only to achieve euphoria, but also as a tactic of self-management. The overall aim of this study is to contextualize lay beliefs, practices, and experiences of methamphetamine use as a form of self-treatment of symptoms related to chronic opioid use among PWUIO in the Dayton Metro Area of Southwest Ohio, an epicenter of the ongoing opioid crisis.

METHODS

This paper draws on two phases of interviews conducted with 38 individuals who use both heroin/fentanyl and methamphetamine. This paper primarily analyzes qualitative data but includes supplementary information from the structured interview component. Qualitative interview sections were transcribed in their entirety and thematically analyzed.

RESULTS

Participants described learning about methamphetamine as a tactic to treat opioid withdrawal symptoms through social networks and through personal experimentation. Many participants suggested that methamphetamine was helpful in relieving exhaustion, alleviating some acute physical symptoms of opioid withdrawal, and providing a psychological distraction, although some admitted that methamphetamine use could incur additional health risks. To effectively use methamphetamine as a tactic of self-treatment, participants emphasized the importance of timing and dosing.

DISCUSSION

Among PWUIO in the Dayton area, methamphetamine use as a tactic to self-manage opioid withdrawal must be studied in relation to historical and evolving patterns of illicit opioid use and associated risks. More research is needed to understand the long-term health impacts of this emergent practice of polydrug use.

Divergent Electrophysiological Effects of Loperamide and Naloxone in a Sensitive Whole-Heart Model

Several case reports suggest QT prolongation leading to ventricular arrhythmias with fatal outcome after intoxication with the μ-opioid receptor agonist and anti-diarrheal agent loperamide. The number of cases of loperamide misuse are growing due to its potential stimulating effects. Loperamide intoxications can be treated by naloxone. However, previous reports described a further QT prolongation associated with naloxone administration. Therefore, the aim of this study was to investigate the effects of loperamide and naloxone on the cardiac electrophysiology in a sensitive whole-heart model. Twenty-six hearts of New Zealand White rabbits were retrogradely perfused in a modified Langendorff apparatus. Monophasic action potentials were recorded by endo- and epicardially positioned catheters. Hearts were stimulated at different cycle lengths, thereby obtaining action potential duration at 90% of repolarization (APD₉₀) and QT intervals. Programmed ventricular stimulation was used to assess ventricular vulnerability. Fourteen hearts were perfused with ascending concentrations of loperamide (0.2 μM, 0.35 μM, and 0.5 μM) after obtaining baseline data. Another 12 hearts were treated with naloxone (0.1 μM, 0.5 μM, 2 μM). Loperamide led to a significant increase in QT interval, APD₉₀, and ventricular tachycardia (VT) episodes. In contrast, naloxone led to a decrease in QT interval and APD₉₀. Accordingly, the number of VT episodes was unaltered. To the best of our knowledge, this is the first experimental study that investigated the effects of loperamide and naloxone in a whole-heart model. Loperamide led to a significant increase in action potential duration and QT interval. Simultaneously, the number of ventricular tachycardias was significantly increased. In contrast, naloxone led to a shortening of the action potential duration without altering arrhythmia susceptibility.

Sex and Gender Differences in the Effects of Novel Psychoactive Substances

Sex and gender deeply affect the subjective effects and pharmaco-toxicological responses to drugs. Men are more likely than women to use almost all types of illicit drugs and to present to emergency departments for serious or fatal intoxications. However, women are just as likely as men to develop substance use disorders, and may be more susceptible to craving and relapse. Clinical and preclinical studies have shown important differences between males and females after administration of “classic” drugs of abuse (e.g., Δ9-tetrahydrocannabinol (THC), morphine, cocaine). This scenario has become enormously complicated in the last decade with the overbearing appearance of the new psychoactive substances (NPS) that have emerged as alternatives to regulated drugs. To date, more than 900 NPS have been identified, and can be catalogued in different pharmacological categories including synthetic cannabinoids, synthetic stimulants (cathinones and amphetamine-like), hallucinogenic phenethylamines, synthetic opioids (fentanyls and non-fentanyls), new benzodiazepines and dissociative anesthetics (i.e., methoxetamine and phencyclidine-derivatives). This work collects the little knowledge reached so far on the effects of NPS in male and female animal and human subjects, highlighting how much sex and gender differences in the effects of NPS has yet to be studied and understood.

Pharmacological Aspects of Over-the-Counter Opioid Drugs Misuse

Several over-the-counter (OTC) drugs are known to be misused. Among them are opioids such as codeine, dihydrocodeine, and loperamide. This work elucidates their pharmacology, interactions, safety profiles, and how pharmacology is being manipulated to misuse these common medications, with the aim to expand on the subject outlined by the authors focusing on abuse prevention and prevalence rates. The reviewed literature was identified in several online databases through searches conducted with phrases created by combining the international non-proprietary names of the drugs with terms related to drug misuse. The results show that OTC opioids are misused as an alternative for illicit narcotics, or prescription-only opioids. The potency of codeine and loperamide is strongly dependent on the individual enzymatic activity of CYP2D6 and CYP3A4, as well as P-glycoprotein function. Codeine can also be utilized as a substrate for clandestine syntheses of more potent drugs of abuse, namely desomorphine (“Krokodil”), and morphine. The dangerous methods used to prepare these substances can result in poisoning from toxic chemicals and impurities originating from the synthesis procedure. OTC opioids are generally safe when consumed in accordance with medical guidelines. However, the intake of supratherapeutic amounts of these substances may reveal surprising traits of common medications.

Non-medical use of loperamide in the UK and the USA

BACKGROUND

Loperamide is a mu-opioid receptor agonist that is available as an over-the-counter anti-motility agent in the US and UK; recommended maximum doses of 12-16 mg/day. Anecdotal reports of non-medical use (NMU) have increased over the past decade with supra-therapeutic doses (70-800 mg/day) associated with cardiotoxicity. Little data exists on the prevalence of loperamide NMU.

AIM

The aim of this study was to determine the prevalence of loperamide NMU in the UK and US and to describe characteristics of non-medical loperamide users.

DESIGN

The Researched, Abuse, Diversion and Addiction Related Surveillance (RADARS® ) Survey of Nonmedical Use of Prescription Drugs (NMURx) was utilized to study NMU of loperamide among the adult population in the UK and US in 2017. The RADARS® NMURx is anonymous and self-administered online.

METHODS

A total of 40,029 completed surveys were included (10,019 from the UK and 30,010 from the US). Respondents were asked questions about medical and NMU of loperamide, frequency of and reasons for NMU, route of use problematic drug use markers, and demographics.

RESULTS

Prevalence of lifetime loperamide use (95% CI) and lifetime NMU of loperamide were: UK 28.5% (27.67-29.4), and 0.66% (0.5-0.8), respectively; US 33.7% (33.1-34.2), and 5.19% (4.9-5.5), respectively. Problematic drug use markers were elevated in those who reported NMU of loperamide in both the UK and US, however high-risk use was more prevalent in the UK than in the US.

CONCLUSION

NMU of loperamide is common. In the current international environment of opioid addiction involving both therapeutic and illicit opioids, awareness of the NMU of loperamide is important.

Loperamide overdose causing torsades de pointes and requiring Impella temporary mechanical support: a case report

Background

Loperamide is a widely available oral μ-opioid receptor agonist, and loperamide abuse is increasing by those seeking intoxication. Loperamide has potent QTc-prolonging properties, placing patients at risk for ventricular arrhythmias and sudden cardiac death.

Case summary

A 23-year-old woman was found to be in pulseless ventricular fibrillation with a QTc of 554 ms and received multiple defibrillations and IV lidocaine. Her toxicology studies were negative. She subsequently experienced multiple episodes of torsades de pointes and was found to be in cardiogenic shock with a left ventricular ejection fraction of 5%. Following multiple defibrillations, an Impella® mechanical circulatory support device was placed, and she was given IV magnesium and IV lidocaine. After mechanical circulatory support was withdrawn, she experienced major bleeding and was found to have a deep vein thrombosis, bilateral radial artery thrombosis, and multiple pulmonary embolisms in the setting of heparin-induced thrombocytopenia. After stabilizing, she admitted to taking 80 tablets of loperamide 2 mg in pursuit of euphoria.

Discussion

Loperamide is an increasingly popular agent of abuse. Loperamide-associated ventricular arrhythmias are rare with normal doses but more common with high doses, chronic ingestion, or interacting medications. Loperamide cardiotoxicity may be prolonged due to a long half-life and accumulation. Loperamide abuse may be under-recognized, leading to delays in treatment. Intravenous fluids, magnesium supplementation, chronotropes, transcutaneous or transvenous pacing, and defibrillation may be helpful in mitigating loperamide-associated polymorphic ventricular tachycardia. Clinicians should monitor for drug interactions in patients taking loperamide and screen for electrocardiographic abnormalities in those taking chronic or high-dose loperamide.

Multi-dose oral abuse deterrent formulation of loperamide using hot melt extrusion

Loperamide, an over the counter anti-diarrheal drug, also infamously referred to as "poor man's methadone". Due to the ease of availability and low price, people/patients abuse it by consuming more than 30 tablets to achieve euphoric effect and to combat opioid withdrawal. But supratherapeutic doses of loperamide result in severe respiratory depression, cardiac dysrhythmia and mortality. To address this issue, we developed a unique and innovative technology to deter multi-dose oral abuse. The concept is to design a tablet which can immediate release loperamide in diarrheic patients (single tablet) while stops loperamide release in case of intentional multi-dose ingestion. Loperamide was molecularly dispersed into gastric soluble cationic polymers - Eudragit® EPO and Kollicoat® Smartseal 100P using hot melt extrusion to obtain filament. Filaments were milled and compressed into tablets ((Eudragit® EPO (SJU1) and Kollicoat® Smartseal (SJU2)) with optimized amount of L-Arginine. Dissolution in 250 mL of Fasted state simulated gastric fluid (FaSSGF) revealed that single tablet of Imodium® (marketed formulation) and SJU1 showed >85% of release within 15 min. Most importantly, in multi-unit dissolution (15 tablets), Imodium® exhibited >90% release but SJU tablets showed <2% of drug release thus demonstrating its ability to deter multi-dose oral abuse.

The unsuspected threat of three opioid-like substitutes

The opioid epidemic has left its toll on the United States with millions suffering from an opioid use disorder and tens of thousands dying from overdoses each year. With intentions to combat the crisis, health providers have been prescribing less opioids, which resulted in an unintentional increase in the abuse of other opioid-like substances. Three emerging drugs of abuse have been noted in the literature as having increased abuse potential in light of recent trends. Kratom, an herbal supplement, gabapentin, a prescription nerve pain and anticonvulsant medication, and loperamide, an over-the-counter antidiarrheal medication. These have all displayed opioid-like properties at high doses and used to alleviate opioid withdrawal. Healthcare clinicians and patients might not be aware of the potential risks involved with misusing or abusing these opioid substitutes. This article discusses the increased usage of kratom, gabapentin, and loperamide, the abuse potential, adverse effects and withdrawal symptoms of each drug, and nursing implications that impact inpatient safety and management.

Radiographic dose-dependency study of loperamide effects on gastrointestinal motor function in the rat. Temporal relationship with nausea-like behavior

BACKGROUND

Loperamide is a potent mu opioid receptor agonist available over the counter to treat diarrhea. Although at therapeutic doses loperamide is devoid of central effects, it may exert them if used at high doses or combined with drugs that increase its systemic and/or central bioavailability. Recently, public health and scientific interest on loperamide has increased due to a growing trend of misuse and abuse, and consequent reports on its toxicity. Our aim was to evaluate in the rat the effects of increasing loperamide doses, with increasing likelihood to induce central effects, on gastrointestinal motor function (including gastric dysmotility and nausea-like behavior).

METHODS

Male Wistar rats received an intraperitoneal injection of vehicle or loperamide (0.1, 1, or 10 mg kg^-1 ). Three sets of experiments were performed to evaluate: (a) central effects (somatic nociceptive thresholds, immobility time, core temperature, spontaneous locomotor activity); (b) general gastrointestinal motility (serial X-rays were taken 0-8 hours after intragastric barium administration and analyzed semiquantitatively, morphometrically, and densitometrically); and (c) bedding intake (a rodent indirect marker of nausea). Animals from sets 1 and 3 were used to evaluate gastric dysmotility ex vivo at 2 and 4 hours after administration, respectively.

KEY RESULTS

Loperamide significantly induced antinociception, hypothermia, and hypolocomotion (but not catalepsy) at high doses and dose-dependently reduced gastrointestinal motor function, with the intestine exhibiting higher sensitivity than the stomach. Whereas bedding intake occurred early and transiently, gastric dysmotility was much more persistent.

CONCLUSIONS AND INFERENCES

Our results suggest that loperamide-induced nausea and gastric dysmotility might be temporally dissociated.

Left Ventricular Regional Wall Motion Abnormality in the Setting of Acute Loperamide Overdose

Loperamide is an inexpensive, over-the-counter antidiarrheal agent with emerging reports of overdose due to its opioid properties. Although it is considered by many patients to be safe, cardiotoxicity has been reported, prompting the United States Food and Drug Administration to release a warning regarding the arrhythmogenic potential of loperamide. We present a case of a 32-year-old male presenting in acute loperamide overdose and subsequent cardiac dysrhythmia with focal wall motion abnormalities on echocardiogram. This finding has not been previously reported in the literature and is unique in this clinical presentation. We also highlight the potential mechanisms for loperamide cardiotoxicity and its challenging management.

Loperamide-induced cardiotoxicity in rats: Evidence from cardiac and oxidative stress biomarkers

At therapeutic dose, loperamide is a safe over-the-counter antidiarrheal drug but could induce cardiotoxic effect at a supratherapeutic dose. In this study, we use cardiac and oxidative biomarkers to evaluate loperamide-induced cardiotoxicity in rats. Rats were orally gavaged with 1.5, 3, or 6 mg/kg body weight (BW) of loperamide hydrochloride for 7 days. The results after 7 days administration of loperamide, revealed dose-dependent increase (P < 0.05) in aspartate aminotransferase, lactate dehydrogenase, creatine kinase-MB, and serum concentration of cardiac troponin I, total homocysteine, and nitric oxide. A 50% decrease in antioxidant enzymes activity was observed at 6 mg/kg BW. Furthermore, malondialdehyde and fragmented DNA also increased significantly in the heart of the treatment groups. Loperamide provoked cardiotoxicity through oxidative stress, lipid peroxidation, and DNA fragmentation in rats. This study has provided a possible biochemical explanation for the reported cardiotoxicity induced by loperamide overdose.

Loperamide induced cardiac arrhythmia successfully supported with veno-arterial ECMO (VA-ECMO), molecular adsorbent recirculating system (MARS) and continuous renal replacement therapy (CRRT)

Introduction: This case of Loperamide misuse had refractory ventricular arrhythmias and was successfully supported by VA ECMO. Loperamide is currently available without prescription and can be obtained in large quantities over the internet despite Food and Drug Administration (FDA) 2016 black box warning noting cardiac toxicity. This case illustrates the life-threatening toxicity of loperamide and suggests a supportive modality to provide clinical time while the drug is cleared endogenously or exogenously. Case report: A 36-year-old female was found minimally responsive. Vital signs and monitoring revealed wide complex bradycardia, undetectable blood pressure, hypothermia, bradypnea, and hypoglycemia. The rhythm degenerated to polymorphic ventricular tachycardia cardia refractory to multiple ACLS protocols. VA-ECMO was initiated with immediate stabilization. Subsequent history revealed massive consumption of loperamide taking 400-600 mg daily. Highest known loperamide and N-desmethyl-loperamide levels were 32 and 500 ng/ml respectively. Since loperamide and metabolites are known to be protein bound, molecular adsorbent recirculating system (MARS) was initiated for toxin clearance. Additionally, she developed acute renal failure supported by CRRT. She was ultimately weaned from ECMO, MARS, and CRRT and discharged neurologically intact on hospital day 12. Discussion: VA ECMO for hemodynamic support provided the needed time for natural resolution of the cardiac toxicity while providing adequate perfusion. MARS was used in the setting of highly protein bound toxins, but drug clearance could not be demonstrated through serial levels. VA ECMO (or referral to a center with VA ECMO) should be considered with lethal loperamide-induced cardiotoxicity and perhaps other cardio-toxins.

Loperamide Mimicking Brugada Pattern

Brugada syndrome is an inherited arrhythmia that increases a patient's risk of sudden cardiac death. Certain pharmacologic agents may induce a transient Brugada pattern on surface electrocardiogram (EKG). One of these is loperamide, an over-the-counter agent commonly used to manage diarrhea. We report the case of a patient who experienced EKG changes that mimicked Brugada pattern after excessive intake of loperamide.

Digital Trespass: Ethical and Terms-of-Use Violations by Researchers Accessing Data From an Online Patient Community

With the expansion and popularity of research on websites such as Facebook and Twitter, there has been increasing concern about investigator conduct and social media ethics. The availability of large data sets has attracted researchers who are not traditionally associated with health data and its associated ethical considerations, such as computer and data scientists. Reliance on oversight by ethics review boards is inadequate and, due to the public availability of social media data, there is often confusion between public and private spaces. In addition, social media participants and researchers may pay little attention to traditional terms of use. In this paper, we review four cases involving ethical and terms-of-use violations by researchers seeking to conduct social media studies in an online patient research network. These violations involved unauthorized scraping of social media data, entry of false information, misrepresentation of researcher identities of participants on forums, lack of ethical approval and informed consent, use of member quotations, and presentation of findings at conferences and in journals without verifying accurate potential biases and limitations of the data. The correction of these ethical lapses often involves much effort in detecting and responding to violators, addressing these lapses with members of an online community, and correcting inaccuracies in the literature (including retraction of publications and conference presentations). Despite these corrective actions, we do not regard these episodes solely as violations. Instead, they represent broader ethical issues that may arise from potential sources of confusion, misinformation, inadequacies in applying traditional informed consent procedures to social media research, and differences in ethics training and scientific methodology across research disciplines. Social media research stakeholders need to assure participants that their studies will not compromise anonymity or lead to harmful outcomes while preserving the societal value of their health-related studies. Based on our experience and published recommendations by social media researchers, we offer potential directions for future prevention-oriented measures that can be applied by data producers, computer/data scientists, institutional review boards, research ethics committees, and publishers.

Novel Drugs of Abuse

Novel drugs of abuse are synthetic illicit drugs, or analogues of known illicit drugs, that can be more potent. Novel drugs of abuse are often labeled as designer drugs, research chemicals, legal highs, or psychoactive substances. They are often sold as designated legal or nondrug products, such as incense, plant food, or bath salts, with labeling such as "Not for Human Consumption" or "For Use in Research Only." The prevalence of use of novel drugs of abuse is difficult to determine because specific drugs, compounds, and availability of these drugs are constantly evolving. Changes in chemical structures lead to heterogeneity in physiologic response and clinical symptoms, even within the same category of drug. Pediatricians and emergency medicine physicians should be knowledgeable about novel drugs of abuse and their resulting symptoms for prevention and identification of their use.

Pharmacologic Treatment of Opioid Use Disorder: a Review of Pharmacotherapy, Adjuncts, and Toxicity

Opioid use disorder continues to be a significant source of morbidity and mortality in the USA and the world. Pharmacologic treatment with methadone and buprenorphine has been shown to be effective at retaining people in treatment programs, decreasing illicit opioid use, decreasing rates of hepatitis B, and reducing all cause and overdose mortality. Unfortunately, barriers exist in accessing these lifesaving medications: users wishing to start buprenorphine therapy require a waivered provider to prescribe the medication, while some states have no methadone clinics. As such, users looking to wean themselves from opioids or treat their opioid dependence will turn to alternative agents. These agents include using prescription medications, like clonidine or gabapentin, off-label, or over the counter drugs, like loperamide, in supratherapeutic doses. This review provides information on the pharmacology and the toxic effects of pharmacologic agents that are used to treat opioid use disorder. The xenobiotics reviewed in depth include buprenorphine, clonidine, kratom, loperamide, and methadone, with additional information provided on lofexidine, akuamma seeds, kava, and gabapentin.

In further defense of nonclinical abuse liability testing of biologics

Risk assessment is not a choice. Drug Abuse Liability (DAL) is mandated under international and national drug control statutes for all drugs targeting the CNS. Once administered to humans many biologics may have long-lived or permanent physiological effects that make DAL testing arduous. We respond to premises of a recently published position on DAL testing of biologics by de Zafra et al. (2018). We propose that, at a minimum, Sponsors submitting a Biologics Licensure Application (BLA) must think "outside the box" and include differential study designs for the same three core small NME assays detailed in the current DAL guidelines (self-administration, drug discrimination, and dependence liability). Abuse liability testing for drug scheduling decisions for marketing approval are not excluded or limited from risk assessment analysis simply because the entity is a biologic. In fact, more robust study designs may be necessary to address alterations in the reinforcing and discriminative stimulus effects of common drugs of abuse, as well as the dependence liability of the biologic, itself.

Is there such a thing as a 'lope' dope? Analysis of loperamide-related European Medicines Agency (EMA) pharmacovigilance database reports

Background

Among over-the-counter (OTC) drugs, loperamide has recently emerged for its potential of misuse and cardiotoxicity issues. Hence, we aimed here at assessing the loperamide-related cases being reported to the EMA's EudraVigilance (EV) database.

Methods

All spontaneous EV reports relating to loperamide misuse/abuse/dependence/withdrawal and cardiotoxicity issues were here retrieved, performing a descriptive analysis.

Findings

During the years 2005–2017, EV collected a number of 1,983 (out of a total of 7,895; 25.11%) loperamide-related misuse/abuse/dependence/withdrawal adverse drug reaction (ADR) reports, with a progressively increasing trend since 2014. Most cases were classified as drug use disorder (37.4%) or intentional overdose (25.4%). Loperamide was used on its own in 41.9% of cases; remaining, polydrug, cases included antidepressants; benzodiazepines; and other OTCs. Some 1,085 (1,085/7,895 = 13.7%) cardiovascular ADRs were reported, being conduction abnormalities and EKG alterations the most frequently identified.

Conclusions

EV data may support the levels of concern relating to loperamide potential of abuse and associated cardiotoxicity issues.

Methadone Management of Withdrawal Associated With Loperamide-related Opioid Use Disorder

: Loperamide hydrochloride is an over-the-counter anti-diarrheal agent, acting via mu-opioid receptor agonist effects in the intestinal myenteric plexus. Although preclinical investigations suggested that abuse liability associated with loperamide use is low, there are increasing numbers of cases reported to the US Food and Drug Administration, of abuse, dependence, and withdrawal associated with loperamide use. A case of a patient with opioid use disorder, that is, in the form of protracted loperamide excess use, requiring management of withdrawal with methadone is presented. Management of withdrawal from abrupt loperamide discontinuation has not been discussed in the literature. Long-term treatment issues are also described.

Bradycardia and Syncope in a Patient Presenting With Loperamide Abuse

Loperamide is an antidiarrheal agent available as an inexpensive over-the-counter (OTC) medication. In general, it is considered to be safe, but lately, loperamide drug abuse has been reported due to its opioid properties. When used in high doses, several harmful effects including cardiotoxicity, central nervous system (CNS) and respiratory depression have been reported. This prompted the FDA to release a warning in 2016 regarding the arrhythmogenic potential of loperamide. We present a case of a 32-year-old male with a history of polysubstance abuse who presented to the emergency department (ED) requesting “detoxification” from loperamide. The patient complained of opiate withdrawal symptoms including chills, nausea, vomiting, constipation, and abdominal cramps thought to be secondary to the abuse of loperamide. He was found to have right bundle branch block (RBBB) and bradycardia with a heart rate (HR) of 51 beats per min (bpm). He also reported an unexplained syncopal episode, one day prior to visiting the ED. In the current case report, we discuss loperamide abuse, its harmful effects, and management.