Levamisole: A High Performance Cutting Agent

Brain alterations in Cocaine Use Disorder: Does the route of use matter and does it relate to the treatment outcome?

AIMS

Cocaine Use Disorder (CUD) is an important health issue, associated with structural brain abnormalities. However, the impact of the route of administration and their predictive value for relapse remain unknown.

METHODS

We conducted an anatomical MRI study in 55 CUD patients (26 CUD-Crack and 29 CUD-Hydro) entering inpatient detoxification, and 38 matched healthy controls. In patients, a 3-months outpatient follow-up was carried out to specify the treatment outcome status (relapser when cocaine was consumed once or more during the past month). A Voxel-Based Morphometry approach was used.

RESULTS

Compared with controls, CUD patients had widespread gray matter alterations, mostly in frontal and temporal cortices, but also in the cerebellum and several sub-cortical structures. We then compared CUD-Crack with CUD-Hydro patients and found that crack-cocaine use was associated with lower volume in the right inferior and middle temporal gyri, and the right fusiform gyrus. Cerebellar vermis was smaller during detoxification in subsequent relapsers compared to three-months abstainers.

CONCLUSIONS

Patients with CUD display widespread cortical and subcortical brain shrinkage. Patients with preferential crack-cocaine use and subsequent relapsers showed specific gray matter volume deficits, suggesting that different patterns of cocaine use and different clinical outcome are associated with different brain macrostructure.

Tolerant or Intolerant? Learning From Studying Drug Concentrations in the Living and the Dead

ABSTRACT

Tolerance is the diminished response to a drug that occurs when that drug is repeatedly used, and the body adapts to its continued presence. This means that greater blood concentrations are required to achieve desired effects, produce impairment, or cause death. Without case-specific information, the pharmacodynamic impacts of a drug on an individual are difficult to ascertain based on its concentration alone. One starting point, however, is to compare reported findings with reference ranges associated with therapeutic, toxic, and lethal outcomes. Toxicologists have observed concentrations dramatically increase over time in the living population for some drugs to concentrations that can easily be associated with impairment and lethal outcomes. It is, therefore, important to continually monitor and be familiar with drug concentrations found in the living to interpret postmortem concentrations. To emphasize this approach, we compared fentanyl concentrations from JAN 2010 to OCT 2023 in individuals investigated for driving under the influence of drugs to postmortem cases. This comparison highlights the changing nature of tolerance, stresses the importance of not relying solely on reference ranges for result interpretations, and discusses the importance of the autopsy in identifying or ruling out other potential causes of death.

Cocaine-Induced Toxic Leukoencephalopathy: A Case Report

Cocaine is a widely abused controlled substance. Cocaine use is associated with a myriad of side effects and a sequelae of consequences secondary to its harmful nature and potential adulterants, the most recently described and less known sequelae being leukoencephalopathy. In our case, we describe a 58-year-old male who presented to the ED with agitation and acute stroke-like symptoms with reported rapid onset. Cocaine induced toxic leukoencephalopathy is a diagnosis of exclusion, thus other etiologies of disease were ruled out in a full neurological and infectious workup; most importantly consisting of extensive brain imaging, alluding to the diagnosis of acute cocaine induced toxic leukoencephalopathy in an individual with a confirmed history of cocaine and cannabinoid abuse. Although there is no targeted therapy for the condition to our knowledge, we utilized a supportive approach to treatment in contrast to other reported treatment modalities which included the use of steroids, plasma exchange, and intravenous immunoglobulin. Furthermore, we describe the clinical evaluation and treatment throughout the patient's hospital course with his eventual marked improvement from initial presentation.

Volatile drug use and overdose during the first year of the COVID-19 pandemic in the United States

BACKGROUND

Overdose deaths in the United States rose substantially during the COVID-19 pandemic. Disruptions to the drug supply and service provision introduced significant instability into the lives of people who use drugs (PWUD), including volatility in their drug use behaviors.

METHODS

Using data from a multistate survey of PWUD, we examined sociodemographic and drug use correlates of volatile drug use during COVID-19 using multivariable linear regression. In a multivariable logistic regression model, we assessed the association between volatile drug use and past month overdose adjusting for sociodemographic and other drug use characteristics.

RESULTS

Among participants, 52% were male, 50% were white, 29% had less than a high school education, and 25% were experiencing homelessness. Indicators of volatile drug use were prevalent: 53% wanted to use more drugs; 45% used more drugs; 43% reported different triggers for drug use, and 23% used drugs that they did not typically use. 14% experienced a past-month overdose. In adjusted models, hunger (β=0.47, 95% CI: 0.21-0.72), transactional sex (β=0.50, 95% CI: 0.06-0.94), and the number of drugs used (β=0.16, 95% CI: 0.07-0.26) were associated with increased volatile drug use. Volatile drug use was associated with increased overdose risk (aOR=1.42, 95% CI: 1.17-1.71) in the adjusted model.

CONCLUSIONS

Volatile drug use during the COVID-19 pandemic was common, appeared to be driven by structural vulnerability, and was associated with increased overdose risk. Addressing volatile drug use through interventions that ensure structural stability for PWUD and a safer drug supply is essential for mitigating the ongoing overdose crisis.

Adulteration and substitution of drugs purchased in Australia from cryptomarkets: An analysis of Test4Pay

INTRODUCTION

Prohibited drugs in unregulated markets may be adulterated, resulting in increased risks for people who use drugs. This study investigated levels of drug adulteration and substitution of drugs purchased in Australia from cryptomarkets.

METHODS

Data were collected from a darknet forum called Test4Pay from 1 September 2022 to 23 August 2023. Posts were included if they reported the results of drug samples submitted by post to the Vancouver-based Get Your Drugs Tested service, which uses Fourier-transform infrared spectroscopy with immunoassay strip tests (fentanyl and benzodiazepines).

RESULTS

Of 103 samples, 65% contained only the advertised substance, 14% contained the advertised substance in combination with other psychoactive and/or potentially harmful substances and for 21%, the advertised substance was absent. Substances sold as MDMA, methamphetamine or heroin were consistently found to contain only the advertised substance, while substances sold as 2C-B, alprazolam or ketamine were the most likely to be completely substituted. Only 4 samples sold as cocaine contained solely the advertised substance, with 13 containing cocaine with adulterants like lidocaine, creatine, levamisole and boric acid (n = 19). No fentanyl contamination was detected. Novel dissociatives and novel benzodiazepines were detected, as well as a nitazene compound.

DISCUSSION AND CONCLUSIONS

Drug markets under prohibition continue to contain numerous unexpected substances, some of which can elevate risk of harm. Cryptomarkets are not immune to this problem, despite review systems, which should, in theory, make vendors more accountable for the quality of their stock. These findings demonstrate a need for expansion of local drug checking services in Australia.

Toxicity and Toxicokinetics of a Four-Week Repeated Gavage of Levamisole in Male Beagle Dogs: A Good Laboratory Practice Study

Levamisole (LVM) is considered an immunomodulatory agent that has the potential to treat various cancer and inflammation diseases. However, there is still much debate surrounding the toxicokinetic and toxicological information of LVM. Therefore, it is crucial to assess its toxicity to provide useful data for future human LVM risk assessments. In this study, a barrier environment was established under the guidance of good laboratory practice (GLP) at the Fujian Center for New Drug Safety Evaluation. Male beagle dogs were orally administered with 5, 15, and 30 mg/kg of LVM daily for four weeks. Toxicity assessment was based on various factors such as mortality, clinical signs, food and water consumption, body weight, body temperature, electrocardiogram, ophthalmological examination, hematology, serum biochemistry, organ/body coefficients, histopathological study, and toxicokinetic analysis. The results of this study showed that LVM did not exhibit any significant toxicological effects on beagle dogs at the exposure levels tested. A no observed adverse effect level (NOAEL) of LVM was set at 30 mg/kg/day for male beagle dogs, which is equivalent to a 12-fold clinical dose in humans. Moreover, the repeated exposure to LVM for four weeks did not lead to any bioaccumulation. These findings provide valuable insights for future human LVM risk assessments.

Testing the test strips: laboratory performance of fentanyl test strips

BACKGROUND

The overdose crisis driven by synthetic opioids continues to escalate in the USA. We evaluated the efficacy of multiple manufacturing lots of a fentanyl test strip (FTS) to detect fentanyl and fentanyl analogs and assessed cross-reactivity with possible interferences.

METHODS

Drug standards were dissolved in water in a laboratory setting and serially diluted. Drug dilutions were tested using five different manufacturing lots of BTNX Rapid Response (20 ng/mL cutoff) lateral flow chromatographic immunoassay strips to assess lot-to-lot variability for FTS sensitivity and cross-reactivity for the analytes of interest.

RESULTS

All five manufacturing lots cross-reacted with fentanyl and eleven fentanyl analogs. Diphenhydramine, lidocaine, MDMA, and methamphetamine were found to cause false positives with the strips. There was notable lot-to-lot variability in the sensitivity of the strips for fentanyl, fentanyl analogs, and known interferences.

DISCUSSION

FTS remains an important overdose prevention tool, but lot-to-lot variability in performance complicates robust instructions that balance the prevention of false positives and false negatives. Continued lot-to-lot performance assessment is recommended to ensure health education for FTS remains accurate. More sophisticated drug checking technologies and services are needed in the community landscape to augment personal FTS use to facilitate informed consumption and overdose risk mitigation.

In Support of Community Drug Checking Programs: Position Statement of AMERSA, Inc. (Association for Multidisciplinary Education and Research in Substance use and Addiction)

BACKGROUND

Position statements clarify key issues that are in alignment with the vision, mission, and values of the AMERSA, Inc. (Association for Multidisciplinary Education and Research in Substance use and Addiction). This Position Statement, endorsed by the AMERSA Board of Directors on October 3, 2023, amplifies the position of the organization, guides their activities, and informs the public and policymakers on the organization's stance on this issue.

ISSUE

The unregulated drug supply in the United States evolves constantly, leaving those who use drugs potentially unaware of new adulterants in their drugs. Not knowing that information can leave people vulnerable to serious adverse events such as fatal overdoses, wounds, and other health consequences. Without real-time data on the composition of drugs available in a community, healthcare providers and public health practitioners are left with insufficient data, making it increasingly difficult to know how to best serve people who use drugs. In this context, community-based drug checking has become recognized as an important harm reduction strategy with the potential to provide those who use drugs with more information about their supply.

RECOMMENDATIONS

It is imperative to expand funding and increase access to drug checking programs in communities across the United States. Key policy changes, such as those related to decriminalizing drug and drug paraphernalia possession, are needed to increase the utilization of drug checking programs. Protection of persons who use drugs through harm reduction strategies, including drug checking programs needs to be widely available and accessible.

Rheumatic masqueraders: mimics of primary vasculitis - a case-based review

INTRODUCTION

Vasculitis conditions are often serious and sometimes fatal diseases, therefore it is paramount to diagnose correctly and treat appropriately. Mimics of primary vasculitis can include either non-inflammatory syndromes or secondary vasculitis where the underlying etiology of the vasculitis is being driven by infection, malignancy, drug-effect or other.

AREAS COVERED

This review comprises six individual cases of vasculitis mimics. Each case is presented and the clinical, radiographic, and histological features that distinguish the case from primary vasculitis are highlighted. Key mimics in large, medium and small vessel vasculitis are outlined.

EXPERT OPINION

The diagnosis of vasculitis requires a comprehensive assessment of clinical, radiographic, and histologic features. Clinicians should be familiar with mimics of primary vasculitis conditions. In the case of non-inflammatory mimics, it is important to differentiate from primary vasculitides in order to avoid unnecessary and potentially harmful immunosuppression. For cases of secondary vasculitis, identification of the correct etiologic cause is critical because treatment of the underlying stimulus is necessary for successful management and outcomes.

Pharmacokinetic profiles and egg residue patterns of levamisole in laying hens at two dosing rates and two routes of administration

The levamisole maximum residue limit for edible fat, kidney, and muscle of chickens is 0.01 mg/kg. However, no maximum residue limit has been established for eggs. In the present study, the pharmacokinetic profile and levamisole residue in the eggs from laying hens were investigated using ultra-performance liquid chromatography-tandem mass spectrometry. A single dose of levamisole (30 mg/kg) was administered via the intramuscular or oral route, and an additional egg residue study was performed with 300 or 600 mg/kg commercial LEV drug (30 or 60 mg/kg as levamisole) orally. The limit of quantification was 0.0056 μg/mL and 0.0015 mg/kg for plasma and eggs, respectively. The plasma concentration was below the limit of quantification 10 and 12 h after intramuscular and oral administration, respectively. The half-life of the absorption phase was comparable between the intramuscular and oral routes, which was approximately 1 h, and the mean maximum concentration value was significantly higher in intramuscular (2.29 ± 0.30 μg/mL) than in oral (1.45 ± 0.38 μg/mL) route. The relative oral bioavailability after intramuscular administration was 92.3%. In the egg residue study, dose-dependent area under concentration and maximum concentration were observed after single oral administration of 30 and 60 mg/kg egg residue, and the calculated withdrawal period for both 30 and 60 mg/kg groups based on the positive list system standard (0.01 mg/kg) was 7 d after the treatment.

Management of Rat Lungworm Disease (Neuroangiostrongyliasis) Using Anthelmintics: Recent Updates and Recommendations

While there have been legitimate concerns in the past regarding the use of anthelmintics for the management of neuroangiostrongyliasis (rat lungworm disease), recent studies demonstrate that they can be considered safe and efficacious, particularly albendazole, which is regarded as the choice anthelmintic for its management. However, physician hesitancy to prescribe, as well as problems of availability persist, at least in Hawaii, which is considered the epicenter of this disease in the US. As a result, many patients suffer a diminished quality of life or even death. Here, we discuss recent studies that provide insights into new treatments and preventative interventions, which can be more rigorously used for the management of neuroangiostrongyliasis. In summary, results from recent studies suggest that albendazole and avermectins are beneficial for post-exposure management, pyrantel pamoate is beneficial as a post-exposure prophylactic, and levamisole is deserving of further study for the treatment of neuroangiostrongyliasis.

Exploring e-psychonauts perspectives towards cocaine effects and toxicity

Background

According to the World Drug Report, cocaine is the second most used drug globally after cannabis. Online discussion forums enable the understanding of authentic drug users’ experience as it is anonymous. Therefore, this study determined the uses, effects and toxicity of cocaine from the perspectives’ of e-psychonauts.

Methods

A qualitative study was conducted using six popular discussion forums. From these discussion forums, 1229 posts from 50 threads were subject to thematic analysis. Hence, the information from these threads were examined carefully for patterns and codes among the data. The codes were then collated into subthemes and themes.

Results

The four main themes emerging from the study were related to cocaine characteristics and use, e-psychonauts’ knowledge and experience, desired effects and adverse events. The main characteristic associated with cocaine use was purity that was highest in the US being nearest to the source. The most common cutting agent encountered in cocaine samples was levamisole that increased the chances of immunosuppression and cardiovascular toxicity. Purity depended on the source of purchase that included street dealers, dark web and surface web. Hence, e-psychonauts recommended purchase of cocaine from known dealers rather than websites with unknown sources. E-psychonauts mainly used cocaine in social context and parties or to self-medicate against anxiety and depression. Effects desired from cocaine use were mainly euphoria and increased energy. However, tachycardia and myocardial infarction were the main adverse events. It is noteworthy to mention that myocardial infarction was idiosyncratic and was often lethal. Myocardial infarction was more often reported when cocaine was combined with alcohol due to the production of cocaethylene. Social harm was also reported as a consequence for the use of cocaine that resulted in homelessness and broken relationships.

Conclusion

Online discussion forums allowed the understanding of e-psychonauts’ experience with cocaine use. Not only it informed about the sources and modalities of use of cocaine but also about the adverse events and social harm associated with cocaine use. The present findings serve as useful information for practitioners and healthcare professionals dealing with cocaine users.

Multifocal leukoencephalopathy associated with intensive use of cocaine and the adulterant levamisole in a 29-year old patient

Levamisole is a common adulterant of cocaine and has been associated with reversible leukoencephalopathy in cocaine users. We report a case of two episodes with severe neurological symptoms and multifocal white matter lesions with brainstem and cerebellar involvement in a 29-year-old man after sporadic cocaine consumption. A urinalysis was positive for levamisole. Neurological deficits as well as MRI presentation improved after cessation of levamisole exposure and two courses of intravenous high-dose glucocorticoid therapy. Early diagnosis of levamisole-induced multifocal leukoencephalopathy and treatment with corticosteroids without delay is essential for a good recovery from neurological symptoms. Although cocaine is one of the most prevalent abused illicit drugs, cocaine- and levamisole-induced multifocal leukoencephalopathy is underdiagnosed as this disorder is not often described in the literature and anamnesis of drug abuse is not admitted by the patient. Therefore, an additional screening for cocaine and levamisole in clinical practice is useful in similar cases to support the diagnosis.

Double Suicide Due to the Ingestion of Levamisole-Adulterated Cocaine: Case Report and Review of the Literature

Suicide is a major public health issue and the risk of attempting and committing suicide increases with age. We present the case of an elderly couple who decided to commit suicide together by self-poisoning using levamisole-adulterated cocaine. The choice of committing a double suicide, the method selected (self-poisoning), the drug self-administered (cocaine), and the route of administration (ingestion) are events rarely encountered in the forensic pathology practice, especially not in combination. In this article, we will review the literature regarding the frequency and features of these methods of suicide. An overview of the effects and mechanism of action of levamisole is also provided, highlighting the importance of including this substance and its metabolites in the routine toxicological analyses for cocaine deaths.

Cocaine Induced Biliary Tree Obstruction in a Middle-Aged Male

A sixty-two-year-old male with a history of extensive crack cocaine use and cholecystectomy presented to the emergency department with abdominal pain, nausea, vomiting, and urobilia. The physical exam revealed moderate epigastric tenderness without scleral icterus or jaundice. The patient's total bilirubin was elevated at 5.2, and his direct bilirubin was 3.7. A computed tomography angiogram (CTA) of the abdomen and pelvis subsequently showed a 3.1 x 2.8 cm mass compressing porta hepatis. A magnetic resonance cholangiopancreatography (MRCP) showed a 4.9 x 3.0 cm mass at the porta hepatis with corresponding biliary duct obstruction at that level. An endoscopic retrograde cholangiopancreatography (ERCP) was performed with stent placement and brush biopsy, which showed predominantly benign ductal epithelium with rare, atypical cells and stenosis of the proximal common bile duct suggestive of cholangiocarcinoma. Cytology was performed on the ductal fluid and was also negative. The carbohydrate antigen (CA) 19-9 level at that time was 94.3. We discussed the possibility of performing surgery as an inpatient, but the patient had various psychosocial issues, which prompted a psychiatric evaluation. He subsequently had an internal-external biliary drain placed. The patient was discharged with plans to obtain an endoscopic ultrasound as an outpatient. He was admitted and discharged several times over the span of six months for various issues. He received an endoscopic ultrasound (EUS) at a surrounding hospital. The results were inconclusive, and a repeat EUS was recommended. On the last admission to the hospital for abdominal pain, a CT scan showed no biliary tree obstruction, which was further confirmed with an MRCP. The internal-external biliary drain was removed without recurrence of hyperbilirubinemia. We suspect that the patient's initial symptoms and radiographic findings of a biliary tree mass may have been induced by extrinsic compression secondary to lymphadenopathy caused by an adulterant used in the cutting process of abused cocaine. This is a rare occurrence that has not been described in the literature. There are associations of cocaine use to pulmonary hilar lymphadenopathy, but not biliary lymphadenopathy. We strongly suspect that this patient's obstructive jaundice and extrinsic biliary tree obstruction were caused by underlying cocaine use.

Cocaine and Levamisole Induced Vasculitis

Levamisole adulterated cocaine is a rare cause of anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis. It is increasingly diagnosed because of raised awareness; however, it is still underdiagnosed in part because of its rarity and patients not reporting cocaine use. Here we report a case of levamisole-induced vasculitis. We present a 48-year-old non-Hispanic white male with a past medical history significant for Crohn’s Disease and pneumonia who presented with acute bilateral ear pain and rash. His urinary drug screen was positive, which prompted suspicion of contamination and potential levamisole adulterated cocaine-associated vasculitis. A punch biopsy showed evidence of leukocytoclastic vasculitis and multiple fibrin thrombi further supporting contamination with levamisole. We believe this case highlights the importance of using patient history in guiding diagnostic testing in the setting of acute vasculitis. Once the history of illicit substance use was confirmed, our differential diagnosis and considerations for treatment significantly changed. 

Levamisole, a cocaine cutting agent, induces acute and subchronic systemic alterations in Wistar rats

The use of the anthelmintic levamisole as a cocaine adulterant has been increasing worldwide. Complications caused by this association include systemic vasculitis, agranulocytosis, neutropenia, tissue necrosis, pulmonary hemorrhage, and renal injury. Data about toxicity of levamisole are scarce, therefore the aim of this study was to evaluate the acute and subchronic toxic effects of levamisole in rats. Male Wistar rats received saline or levamisole by intraperitoneal route at the doses of 12, 24 and 36 mg/kg in the acute toxicity test; and at 3, 6 and 12 mg/kg in the subchronic toxicity test. Toxicity was evaluated using behavioral, cognitive, renal, hematological, biochemical and histopathological parameters. Acute administration of levamisole caused behavioral and histopathological alterations. Subchronic administration caused behavioral, cognitive and hematological alterations (p < 0.0001 and p < 0.05, respectively), impairment of liver and kidney functions (p < 0.05), and changes of antioxidant defenses (p ≤ 0.0001). Both administrations produced toxic effects of clinical relevance, which make levamisole a dangerous cutting agent. Furthermore, the knowledge of these effects can contribute to the correct diagnosis and treatment of cocaine dependents with unusual systemic alterations.