A confirmed case of agranulocytosis after use of cocaine contaminated with levamisole

Effect of a Single and Triple Dose of Levamisole on Hematological Parameters in Controlled Inflammation Model

This study aimed to evaluate the impact of single and triple administration of levamisole on the dynamics of hematological parameters during experimental pleuritis. The experiment was performed on female Buffalo rats. Rats were randomly assigned to two equal groups that received 1 and 3 doses of levamisole every 2, 24 and 48 h, respectively. Following the experiment, blood samples for the measurement of hematological parameters were collected. The study group receiving three doses of levamisole observed a significant reduction of red blood cell count at 48 h post administration and an increase in mean corpuscular volume compared to the control inflammation group. The administration of a single dose of levamisole results in a significant increase in hematocrit at 72 h, an increase in white blood cell count at 24 h and 72 h, and an increase in neutrophil count at 72 h compared to the control inflammation group. Administration of a single and triple dose of levamisole showed statistically significant modification of some hematological parameters and thus modulates the inflammatory process. In the lungs, this results in a reduction in leukocyte infiltrations around the bronchi and blood vessels.

Distinct inflammatory profiles in HIV-infected individuals under antiretroviral therapy using cannabis, cocaine or cannabis plus cocaine

OBJECTIVES

To evaluate the effects of cannabis and/or cocaine use on inflammatory, oxidative stress status and circulating monocyte subsets in HIV-infected individuals under antiretroviral therapy.

DESIGN

Soluble CD14 (sCD14), intestinal fatty acid-binding protein (IFABP), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-8, IL-10, C-reactive protein (CRP) and oxidative stress markers were examined. The monocyte subsets and their activation and cytokine production by peripheral blood mononuclear cells (PBMCs) of HIV-1 infected individuals upon lipopolysaccharide (LPS)-stimulation were also investigated.

METHODS

sCD14, IFABP, TNF-α, IL-6, IL-8 and IL-10 levels were evaluated using ELISA, CRP by turbidimetry; lipid peroxidation (TBARS) spectrofluometrically and total thiol levels by using 5-5'-dithio-bis (2-nitrobenzoic acid) reagent. Monocyte subsets and activation were assessed by flow cytometry.

RESULTS

All HIV-infected drug user groups showed higher sCD14 levels compared with HIV+ nondrug users. IFABP was increased in HIV+ drug-users in relation to healthy individuals. Cannabis use lowered the percentages of inflammatory, nonclassical, activated-classic and activated-inflammatory monocytes. Cocaine users showed increased plasmatic TNF-α and TBARS levels, decreased thiols content and lower activated-classic and inflammatory-monocyte percentages. Cannabis-plus-cocaine use increased CRP, IL-8 and IL-6/IL-10 ratio, but decreased thiol content, and inflammatory and activated-classic monocyte percentages. PBMCs of cannabis and cannabis-plus-cocaine users showed low-potential cytokine production either spontaneously or under LPS-stimulation.

CONCLUSION

In HIV infection, the use of cannabis induces predominantly an anti-inflammatory profile. The use of cocaine and cannabis-plus-cocaine showed a mixed pro-inflammatory and anti-inflammatory profile, with predominance of inflammatory status. Further studies are required to better understand the action of these drugs in HIV infection.

Adulterants in crack cocaine in Brazil

Abstract Introduction Brazil is the world’s biggest consumer of crack cocaine, and dependence is a major public health issue. This is the first study to investigate the prevalence of potentially harmful adulterants present in hair samples from Brazilian patients with crack cocaine dependence. Method We evaluated adulterants in hair samples extracted by convenience from 100 patients admitted at the 48 hour-observation unit of Centro de Referência de Álcool, Tabaco e Outras Drogas (CRATOD), Brazil’s largest center for addiction treatment. A cross-sectional analysis was performed with the data obtained. Results Adulterants were found in 97% of the analyzed hair samples. The most prevalent adulterant was lidocaine (92%), followed by phenacetin (69%) and levamisole (31%). Conclusion Adulterants were widely prevalent in hair samples from crack users treated at CRATOD: at least one adulterant was present in virtually all the hair samples collected. This points to a need to monitor adverse effects in the clinical setting in order to provide this high-risk group of patients with prompt and effective care related to the acute and chronic complications associated with these adulterants.

DARK Classics in Chemical Neuroscience: Aminorex Analogues

Aminorex (5-phenyl-4,5-dihydro-1,3-oxazol-2-amine) and 4-methylaminorex (4-methyl-5-phenyl-4,5-dihydro-1,3-oxazol-2-amine) are psychostimulants that have long been listed in Schedules IV and I of the UN Convention on Psychotropic Substances of 1971. However, a range of psychoactive analogues exist that are not internationally controlled and therefore often classified as new psychoactive substances (NPS). Aminorex analogues encompass failed pharmaceuticals that reemerged as drugs of abuse, and newly synthesized substances that were solely designed for recreational use by clandestine chemists. NPS, sometimes also referred to as "designer drugs" in alignment with a phenomenon arising in the early 1980s, serve as alternatives to controlled drugs. Aminorex and its derivatives interact with monoaminergic neurotransmission by interfering with the function of monoamine transporters. Hence, these compounds share pharmacological and neurochemical similarities with amphetamines and cocaine. The consumption of aminorex, 4-methylaminorex and 4,4'-dimethylaminorex (4-methyl-5-(4-methylphenyl)-4,5-dihydro-1,3-oxazol-2-amine) has been associated with adverse events including death, bestowing an inglorious fame on aminorex-derived drugs. In this Review, a historical background is presented, as well as an account of the pharmacodynamic and pharmacokinetic properties of aminorex and various analogues. Light is shed on their misuse as drug adulterants of well-established drugs on the market. This Review not only provides a detailed overview of an abused substance-class, but also emphasizes the darkest aspect of the NPS market, i.e., deleterious side effects that arise from the ingestion of certain NPS, as knowledge of the pharmacology, the potency, or the identity of the active ingredients remains obscure to NPS users.

Recurrent Levamisole-Induced Agranulocytosis Complicated by Bowel Ischemia in a Cocaine User

BACKGROUND Levamisole is a common adulterant of cocaine and up to 69% of seized cocaine in United States contains levamisole. It is a synthetic imidazothiazole derivative which was previously used as an immunomodulating agent for treatment of various connective tissue disorders and colorectal carcinoma. However, it was withdrawn later from the market due to significant toxicity associated with it. CASE REPORT We present the case of a 59-year-old male patient with a history of active cocaine use who presented to the hospital with febrile neutropenia and agranulocytosis. He underwent extensive work-up for neutropenia and was suspected to have it secondary to levamisole-adulterated cocaine. He was treated with antibiotics and granulocyte-stimulating factor. His white cell count improved and he was discharged home. He continued to use cocaine after discharge from the hospital. He returned to the hospital 3 weeks later with recurrent neutropenia and agranulocytosis complicated by septic shock and bowel necrosis which required prolonged antibiotics and a bowel resection. CONCLUSIONS Levamisole-induced agranulocytosis should be considered in patients who present with neutropenia and a history of cocaine use. Physicians should have high clinical suspicion and consider it a potential etiology of agranulocytosis when other causes have been excluded.

Analysis of illicit drugs seized in the Province of Florence from 2006 to 2016

Comprehension of illicit drug market's features at local level is useful to plan and to correctly set-up specific informative and contrast activities. In this paper we report trends, purities and consumption estimations of illicit substances available on the Florentine territory from 2006 to 2016. These data were obtained by the analysis of 10,451 samples seized by the Law Enforcement Agencies in case of personal use offence. Analytical procedures consisted in targeted and untargeted analyses by gas chromatography-flame ionization detector, gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry. The most detected substances were: cannabis (78.0%; resin: 51.7%; herb: 26.3%), cocaine (10.4%), opiates (6.6%; heroin: 6.5%; morphine: 0.1%), ketamine (1.4%), amphetamines (1.3%; 3,4-methylenedioxymethamphetamine - MDMA -: 0.7%; methamphetamine: 0.6%; amphetamine: <0.1%) and methadone (1.3%). Cocaine, heroin and methamphetamine purities were higher than their mean values estimated for the Italian and European market, while THC content in cannabis seizures was unexpectedly below the European mean values. Starting from 2015, a total of 5 new psychoactive substances (NPS) were detected in seized material, mainly composed of white powders (pentedrone, 3-methylmethcathinone, 4-fluoroamphetamine, methoxethamine and AB-FUBINACA). Most of the seizures (75.5%) were from young male adults (14-34 years old). These data contribute to highlight new trends in the illicit drug market in the Tuscany area, but also to verify the persistence of old habits of drug consumption, confirming the need for more effective counteraction and prevention plans, especially among young people, where the diffusion of the legal highs is worrisome, also in consideration of the young age and the unconsciousness of the possible health effects.

Vanishing vasculitis: a case of acute necrotic skin findings without pathologic features of vasculitis from adulterated cocaine

While the usage of illicit drugs in itself carries significant health risks and associated toxicities, drugs that are adulterated to give them volume, alter their psychogenic properties, and make them cheaper to produce are to be considered even more dangerous. Cocaine is one of them, and it is now most commonly being adulterated with levamisole. We report a case of a 37-year-old female with the chief complaint of painful skin lesions and wounds on both of her upper and lower extremities for three weeks duration. She was tested positive for cocaine and had classical purpuric, ecchymotic, and necrotic patches on both ears, which are pathognomonic. She also had multiple wounds in extremities. The cocaine–levamisole related syndrome comprises a set of immunological abnormalities, out of which, ANCA positivity is the most important one. Our patient was ANCA positive. Regarding pathological findings in cocaine adulterated with levamisole syndrome, this can range from the classic finding of leukocytoclastic vasculitis of small vessels to occlusive vascular disease without true vasculitis. Our case’s biopsy showed no vasculitis, and this is why it is important to highlight that cocaine can also cause a pseudo-vasculitic picture. The other possibility that we entertained was that of pyoderma gangrenosum as the skin finding in levamisole-contaminated cocaine, and the lesion was consistent in appearance. Recently, there have been a few case reports of pyoderma gangrenosum from adulterated cocaine with levamisole, where skin findings were consistent with pyoderma gangrenosum; however, serological findings rather favored levamisole vasculopathy or vasculitis. Therefore, we should familiarize ourselves with the multitude of pathological and skin findings that adulterated cocaine can cause and, finally, make ourselves aware that the classical pathological finding of vasculitis in such cases is not always seen.

Cocaine adulteration

Cocaine is a naturally occurring and illicitly used psychostimulant drug. Cocaine acts at monoaminergic neurotransmitter transporters to block uptake of the monoamines, dopamine, serotonin and norepinephrine. The resulting increase of monoamines in the extracellular space underlies the positively reinforcing effects that cocaine users seek. In turn, this increase in monoamines underlies the development of addiction, and can also result in a number of severe side effects. Currently, cocaine is one of the most common illicit drugs available on the European market. However, cocaine is increasingly sold in impure forms. This trend is driven by cocaine dealers seeking to increase their profit margin by mixing ("cutting") cocaine with numerous other compounds ("adulterants"). Importantly, these undeclared compounds put cocaine consumers at risk, because consumers are not aware of the additional potential threats to their health. This review describes adulterants that have been identified in cocaine sold on the street market. Their typical pharmacological profile and possible reasons why these compounds can be used as cutting agents will be discussed. Since a subset of these adulterants has been found to exert effects similar to cocaine itself, we will discuss levamisole, the most frequently used cocaine cutting agent today, and its metabolite aminorex.

Levamisole-Contaminated Cocaine Use in HIV-Infected and Uninfected Unstably Housed Women

A growing number of case reports cite serious health complications linked to the cocaine adulterant, levamisole and women are disproportionately affected; however, the clinical effects are not well established. Between April and October of 2010, we conducted a cross-sectional study among 222 homeless and unstably housed women (116 human immunodeficiency virus [HIV]-infected and 106 HIV-uninfected). Immune markers and behavioral factors were compared in separate models by cocaine and levamisole exposure. Overall, 63% of participants were toxicology positive for cocaine/benzoylecgonine, 85% of whom also tested positive for levamisole. Differences in immune markers did not reach levels of significance among HIV-uninfected persons. Compared to HIV-infected persons who were negative for both cocaine and levamisole, the adjusted odds of low white blood cell count were significantly higher among HIV-infected persons positive for both (p = 0.03), but not for those positive for cocaine only. Neutrophil count and HIV viral load did not differ by cocaine and levamisole status among HIV-infected persons. In a separate model, the adjusted odds of testing positive for levamisole were higher among African American women compared to Caucasian and Asian women (p = 0.02). In the context of high levamisole prevalence, results suggest that decreased immune function as a result of levamisole exposure occurs mainly in individuals who are already immune compromised (e.g., HIV-positive), and race/ethnicity appears to be an important factor in understanding levamisole exposure among cocaine-using women. While larger and geographically diverse studies are needed to elucidate these initial findings, results suggest that levamisole may be one mechanism of immune dysfunction in HIV-infected cocaine-using women.

Is Levamisole-Induced Vasculitis a Relegated Diagnostic Possibility? A Case Report and Review of Literature

Patient: Female, 38

Final Diagnosis: Levamisole induced vasculitis

Symptoms: Skin and joint

Medication: —

Clinical Procedure: None

Specialty: Toxicology

Wide-range screening of psychoactive substances by FIA-HRMS: identification strategies

Recreational drugs (illicit drugs, human and veterinary medicines, legal highs, etc.) often contain lacing agents and adulterants which are not related to the main active ingredient. Serious side effects and even the death of the consumer have been related to the consumption of mixtures of psychoactive substances and/or adulterants, so it is important to know the actual composition of recreational drugs. In this work, a method based on flow injection analysis (FIA) coupled with high-resolution mass spectrometry (HRMS) is proposed for the fast identification of psychoactive substances in recreational drugs and legal highs. The FIA and HRMS working conditions were optimized in order to detect a wide range of psychoactive compounds. As most of the psychoactive substances are acid-base compounds, methanol-0.1 % aqueous formic acid (1:1 v/v) as a carrier solvent and electrospray in both positive ion mode and negative ion mode were used. Two data acquisition modes, full scan at high mass resolution (HRMS) and data-dependent tandem mass spectrometry (ddMS/HRMS) with a quadrupole-Orbitrap mass analyzer were used, resulting in sufficient selectivity for identification of the components of the samples. A custom-made database containing over 450 substances, including psychoactive compounds and common adulterants, was built to perform a high-throughput target and suspect screening. Moreover, online accurate mass databases and mass fragmenter software were used to identify unknowns. Some examples, selected among the analyzed samples of recreational drugs and legal highs using the FIA-HRMS(ddMS/HRMS) method developed, are discussed to illustrate the screening strategy used in this study. The results showed that many of the analyzed samples were adulterated, and in some cases the sample composition did not match that of the supposed marketed substance.

Levamisole enhances the rewarding and locomotor-activating effects of cocaine in rats

BACKGROUND

The Drug Enforcement Agency estimates that 80% of cocaine seized in the United States contains the veterinary pharmaceutical levamisole (LVM). One problem with LVM is that it is producing life-threatening neutropenia in an alarming number of cocaine abusers. The neuropharmacological profile of LVM is also suggestive of an agent with modest reinforcing and stimulant effects that could enhance cocaine's addictive effects.

METHODS

We tested the hypothesis that LVM (ip) enhances the rewarding and locomotor stimulant effects of cocaine (ip) using rat conditioned place preference (CPP) and locomotor assays. Effects of LVM by itself were also tested.

RESULTS

LVM (0-10 mg/kg) produced CPP at 1mg/kg (P<0.05) and locomotor activation at 5mg/kg (P < 0.05). For CPP combination experiments, a statistically inactive dose of LVM (0.1 mg/kg) was administered with a low dose of cocaine (2.5 mg/kg). Neither agent produced CPP compared to saline (P > 0.05); however, the combination of LVM and cocaine produced enhanced CPP compared to saline or either drug by itself (P < 0.01). For locomotor experiments, the same inactive dose of LVM (0.1mg/kg, ip) was administered with low (10 mg/kg) and high doses (30 mg/kg) of cocaine. LVM (0.1 mg/kg) enhanced locomotor activation produced by 10mg/kg of cocaine (P < 0.05) but not by 30 mg/kg (P>0.05).

CONCLUSIONS

LVM can enhance rewarding and locomotor-activating effects of low doses of cocaine in rats while possessing modest activity of its own.

Levamisole-contaminated cocaine: an emergent cause of vasculitis and skin necrosis

The prevalence of cocaine adulterated with levamisole-induced vasculitis is increasing and physicians should be aware of this unique entity. There have been many reports of cutaneous vasculitis syndrome caused by cocaine which is contaminated with levamisole. Levamisole was used as an antihelminth drug and later was rescinded from use in humans due to adverse effects. Through this paper, we will report a 39-year-old crack cocaine user who presented with purpuric rash and skin necrosis of his ear lobes. Levamisole-induced vasculitis syndrome was suspected. A urine toxicology screen was positive for cocaine, opiates, and marijuana. Blood work revealed positive titres of ANA and p-ANCA, as well as anti-cardiolipin antibody. Biopsy taken from the left ear showed focal acute inflammation, chronic inflammation with thrombus formation, and extravasated blood cells. Treatment was primarily supportive with wound care.

Levamisole and cocaine synergism: a prevalent adulterant enhances cocaine's action in vivo

Levamisole is estimated by the Drug Enforcement Agency (DEA) to be present in about 80% of cocaine seized in the United States and linked to debilitating, and sometimes fatal, immunologic effects in cocaine abusers. One explanation for the addition of levamisole to cocaine is that it increases the amount of product and enhances profits. An alternative possibility, and one investigated here, is that levamisole alters cocaine's action in vivo. We specifically investigated effects of levamisole on cocaine's stereotypical and place-conditioning effects in an established invertebrate (planarian) assay. Acute exposure to levamisole or cocaine produced concentration-dependent increases in stereotyped movements. For combined administration of the two agents, isobolographic analysis revealed that the observed stereotypical response was enhanced relative to the predicted effect, indicating synergism for the interaction. In conditioned place preference (CPP) experiments, cocaine produced a significant preference shift; in contrast, levamisole was ineffective at all concentrations tested. For combination experiments, a submaximal concentration of cocaine produced CPP that was enhanced by inactive concentrations of levamisole, indicating synergism. The present results provide the first experimental evidence that levamisole enhances cocaine's action in vivo. Most important is the identification of synergism for the levamisole/cocaine interaction, which now requires further study in mammals.

Aminorex, a metabolite of the cocaine adulterant levamisole, exerts amphetamine like actions at monoamine transporters

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We quantified adulterants in street drugs sold as cocaine.

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We analyzed effects of the most common adulterant levamisole, on neurotransmitter transporters.

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Differences in the selectivity of levamisole can be explained by homology modelling and docking.

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Aminorex, a metabolite of levamisole, modulates neurotransmitter transporters directly.

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Depending on the transporter, aminorex acts as a blocker or as a releaser.

Psychostimulants such as amphetamine and cocaine are illicitly used drugs that act on neurotransmitter transporters for dopamine, serotonin or norepinephrine. These drugs can by themselves already cause severe neurotoxicity. However, an additional health threat arises from adulterant substances which are added to the illicit compound without declaration. One of the most frequently added adulterants in street drugs sold as cocaine is the anthelmintic drug levamisole. We tested the effects of levamisole on neurotransmitter transporters heterologously expressed in HEK293 cells. Levamisole was 100 and 300-fold less potent than cocaine in blocking norepinephrine and dopamine uptake, and had only very low affinity for the serotonin transporter. In addition, levamisole did not trigger any appreciable substrate efflux. Because levamisole and cocaine are frequently co-administered, we searched for possible allosteric effects; at 30 μM, a concentration at which levamisole displayed already mild effects on norepinephrine transport it did not enhance the inhibitory action of cocaine. Levamisole is metabolized to aminorex, a formerly marketed anorectic drug, which is classified as an amphetamine-like substance. We examined the uptake-inhibitory and efflux-eliciting properties of aminorex and found it to exert strong effects on all three neurotransmitter transporters in a manner similar to amphetamine. We therefore conclude that while the adulterant levamisole itself has only moderate effects on neurotransmitter transporters, its metabolite aminorex may exert distinct psychostimulant effects by itself. Given that the half-time of levamisole and aminorex exceeds that of cocaine, it may be safe to conclude that after the cocaine effect “fades out” the levamisole/aminorex effect “kicks in”.

Levamisole toxicity mimicking autoimmune disease

BACKGROUND

Levamisole is present as a contaminant or additive in most cocaine sold in the United States. Cases of agranulocytosis attributed to levamisole-tainted cocaine have been widely described. A vasculopathic reaction to levamisole has also been reported; however, diagnostic features such as antineutrophil cytoplasmic antibody (ANCA) and additional autoimmune marker positivity are not well recognized. As such, many patients are given a misdiagnosis, prompting aggressive and often unnecessary treatment.

OBJECTIVE

We hope to educate practitioners about the clinical and laboratory features of levamisole-induced vasculopathy to ensure accurate diagnosis and management.

METHODS

This was a case series.

RESULTS

Six patients were admitted with purpuric lesions and vasculitic changes on biopsy specimen; 5 of them were given the diagnosis of and treated for autoimmune conditions before their true diagnosis was revealed. All patients had ANCA positivity, and 4 had additional abnormalities in autoimmune markers. All patients reported recent cocaine abuse, and were ultimately given the diagnosis of levamisole-induced vasculopathy.

LIMITATIONS

This observational study is limited by sample size.

CONCLUSIONS

Patients presenting with purpuric lesions with ANCA positivity should be assessed for cocaine exposure. It is important to recognize that levamisole may not only induce ANCA positivity but also other autoimmune marker abnormalities. Patients can often be treated with less aggressive therapeutic strategies than what is used for primary ANCA-associated vasculitides.

Controlling chaos: the perceptions of long-term crack cocaine users in vancouver, british columbia, Canada

People who smoke crack cocaine are described as chaotic and more likely to engage in risky sex, polysubstance use and contract infectious diseases. However, little is known about how individuals perceive smoking crack as compared to other forms of cocaine use, especially injection. We explored the lived experience of people who smoke crack cocaine. Six gender-specific focus groups (n = 31) of individuals who currently smoke crack in Vancouver, Canada, were conducted using a semi-structured interview guide. Focus groups were transcribed and analyzed by constant comparative methodology. We applied Rhodes' risk environment to the phenomenological understanding that individuals have regarding how crack has affected their lives. Subjects reported that smoking rather than injecting cocaine allows them to begin “controlling chaos” in their lives. Controlling chaos was self-defined using nontraditional measures such as the ability to maintain day-to-day commitments and housing stability. The phenomenological lens of smoking crack instead of injecting cocaine “to control chaos” contributes a novel perspective to our understanding of the crack-smoking population. This study examines narratives which add to prior reports of the association of crack smoking and increased chaos and suggests that, for some, inhaled crack may represent efforts towards self-directed harm reduction.

Levamisole-induced vasculitis

Levamisole-contaminated cocaine is an increasingly reported cause of a syndrome characterized by vasculitic skin lesions and immunologic abnormalities. With approximately 70% of cocaine in the United States now contaminated with levamisole, the incidence of this syndrome is likely to increase. We report two cases of this syndrome and review its clinical presentation, course, and prognosis.

p-ANCA-Associated Vasculitis Caused by Levamisole-Adulterated Cocaine: A Case Report

A rare case of a patient with an unusual skin rash after using cocaine is presented. A clinical diagnosis of levamisole-induced vasculitis was made based on initial presentation of purpuric skin lesions involving the ears and positive cocaine on urine toxicology screening. The diagnosis was confirmed after laboratory findings of neutropenia, positive serum levamisole, and a histopathologic test of the skin lesions. The pathophysiology of this condition is discussed. Treatment with methylprednisolone and prednisone led to the resolution of the neutropenia and complete recovery of the skin lesions. With the growing use of levamisole-tainted cocaine, clinicians should be aware of the symptoms of vasculitis and neutropenia induced by this combination of drugs to avoid unnecessary tests and delayed diagnosis.

Cutaneous vasculopathy associated with levamisole-adulterated cocaine

We report a case of cutaneous vasculopathy associated with the use of levamisole-adulterated cocaine. This recently described clinical entity is characterized by a purpuric rash with a predilection for the ears, leukopenia, and anti-neutrophilic cytoplasmic antibody (ANCA) positivity. It is estimated that more than 70% of the current United States cocaine supply is contaminated with levamisole. Levamisole is a widely available, inexpensive, white powder used as a "cutting agent" in cocaine to expand volume and increase profits. It may also increase the euphoric and stimulatory effects of cocaine by increasing brain dopamine levels and producing amphetamine-like metabolites. Our patient exhibited a characteristic rash with involvement of the ears, leukopenia, and cocaine metabolites were detected in serum and urine. The presence of levamisole was confirmed in the urine utilizing gas chromatography-mass spectrometry. ANCA positivity was also present. Punch biopsy of the skin demonstrated vascular thrombosis and necrosis without true vasculitis. We review the literature for reported cases of cocaine-levamisole cutaneous vasculopathy syndrome, highlight the salient immunologic abnormalities, and contrast the features of this entity with idiopathic systemic vasculitis.

The head, neck, and systemic manifestations of levamisole-adulterated cocaine use

Systemic complications of levamisole-adulterated cocaine (LAC) use have recently been described. The objective of this review is to increase awareness of these manifestations among oral and maxillofacial surgeons. LAC exposure through inhalation, nasal insufflation, or injection can induce cutaneous vasculopathy and hematologic abnormalities such as neutropenia or agranulocytosis. Unlike other vasculopathies involving the skin, LAC-induced vascular injury frequently manifests with purpuric and necrotic lesions that involve the face and ears. Oral manifestations have also been reported but are not yet well characterized. The aforementioned hematologic manifestations are not uncommon, and patients exposed to LAC are potentially at higher risk for infectious complications. When manifestations of LAC affect the head, neck, and oral cavity, oral and maxillofacial surgeons may be the first providers to encounter the patient. Early recognition of the clinical signs and laboratory abnormalities will better allow for distinguishing LAC-related effects from various clinical mimics, will facilitate appropriate patient management, and may further contribute to the understanding of the biological effects of LAC.

Vasculopathy, hematological, and immune abnormalities associated with levamisole-contaminated cocaine use

OBJECTIVES

To report 4 cases of cocaine-related purpura and to review previously reported cases of levamisole, levamisole-contaminated cocaine, and cocaine-induced vasculopathy.

METHODS

We describe 4 patients suspected of vasculopathy associated with levamisole-tainted cocaine use. A retrospective review of the literature was performed using the PubMed, PubJet, MD consult, and Cochrane review databases.

RESULTS

Four cases (2 females and 2 males), 46 to 55 years of age, presented with cocaine-related purpura, mainly affecting the ears, neutropenia, and autoantibodies. Skin biopsies revealed a mixed pattern of leukocytoclastic vasculitis and microvascular thrombosis in 2 cases, and pure thrombosis in the third case. The mixed vasculopathic pattern in association with neutropenia, both known adverse effects of levamisole, and levamisole positivity in 2 cases point to this compound as the true etiologic agent in our patients. Eleven cases of levamisole-contaminated cocaine-induced vasculopathy have been described in the English literature. Among these, 10 were females. Age range was 22 to 57 years. Urine levamisole positivity was tested and confirmed in 3 of the 11 cases. The clinical characteristics, laboratory features, histology, treatment, and recovery rates were compared for the published cases of levamisole, levamisole-contaminated cocaine, and cocaine-induced vasculopathy.

CONCLUSIONS

Adulterated cocaine abuse is an increasingly recognized phenomenon in North America. Levamisole is among the many contaminants that have been detected in seized cocaine throughout North America and Europe. Recent reports described an association between levamisole-tainted cocaine and purpuric skin rash, neutropenia, and the presence of autoantibodies.

Levamisole-induced occlusive necrotising vasculitis in cocaine abusers: an unusual cause of skin necrosis and neutropenia

We present three cases describing the various skin manifestations of presumed levamisole-contaminated cocaine use. Antibody-mediated vasculitis and neutropenia were consistent findings in these cases and repeat exposure resulted in distinct dermatologic complications. This phenomenon of levamisole-induced vasculitis and neutropenia is being increasingly described and has characteristic wound manifestations that must be recognised and treated early.

Levamisole-induced necrosis of skin, soft tissue, and bone: case report and review of literature

This represents the largest case of skin necrosis related to levamisole, a common cocaine contaminant, requiring closure with skin grafts, and is the only case resulting in nasal amputation, central upper lip excision, extremity bone necrosis, and above knee amputation. The case report is followed by a review of the literature. Unique considerations for the full-thickness necrosis induced by levamisole vasculitis are highlighted, including antibody level monitoring, need for multiple excisions, timing of skin grafting, and potential for soft tissue and bone necrosis as well. A 54-year-old man presented to an outside facility with fever, generalized weakness, and agranulocytosis, with a history of cocaine use 3 weeks before. After admission, he developed generalized violaceous lesions and an elevated p-antineutrophilic cytoplasmic antibody and was diagnosed with disseminated vasculitis and agranulocytosis secondary to levamisole-contaminated cocaine exposure. On transfer to the authors' facility, 52% TBSA was involved with violaceous, nonblanching lesions, which progressed to full-thickness necrosis. Local wound care continued until necrotic areas fully demarcated and progressive necrosis stabilized, and skin grafting for closure was not performed until antibody levels normalized. Current treatment of levamisole-induced skin rash or necrosis focuses on discontinuation of levamisole. As demonstrated by this case, extensive necrosis secondary to levamisole-induced vasculitis can be successfully treated with multiple excisions until necrosis stabilizes, and then, split-thickness autografts may be applied. In areas with poor vascular supply or areas with poor functional prognosis, amputation may ultimately be required.

Levamisole in cocaine: unexpected news from an old acquaintance

Levamisole is a pharmaceutical with anthelminthic and immunomodulatory properties that was previously used in both animals and humans to treat inflammatory conditions and cancer. Levamisole has been identified as a cocaine adulterant in the United States since 2003. By 2009, the United States Drug Enforcement Administration (DEA) estimated that 69% of the cocaine seized contained levamisole. The first case reports of complications related to levamisole in cocaine users were published in 2009. The objectives of this article are to review the literature regarding the full spectrum of possible complications related to levamisole use for medical purposes, to review the current scope of levamisole-induced complications in cocaine users and to discuss the pharmacological properties that might explain the motivation behind the large-scale adulteration of cocaine with levamisole. Literature review revealed that significant complications were quickly reported when levamisole was used in inflammatory conditions. By 1976, several cases of leukopenia and agranulocytosis were reported. Recurrence with re-exposure was well described and agranulocytosis spontaneously reversed upon discontinuation of therapy. Vasculitis secondary to levamisole treatment was first reported in 1978 and mostly manifests as leukocytoclastic vasculitis, cutaneous necrotising vasculitis and thrombotic vasculopathy without vasculitis. These findings typically, but not invariably, involve the ear lobes. Discontinuation of levamisole therapy was again a critical part of the treatment. Various neurological side effects were described with levamisole therapy, the most concerning complication being multifocal inflammatory leukoencephalopathy (MIL). Literature review identified 203 unique cases of complications in cocaine users that can be attributed to levamisole adulteration. The two principal complications reported are haematological (140 cases of neutropenia) and dermatological (84 cases). Even though these complications can occur in isolation, many cases displayed both simultaneously. No formal case of leukoencephalopathy in the setting of cocaine use has been reported so far. A striking phenomenon is the apparent high level of recurrence (27.1%) of symptoms in cocaine users after re-exposure to cocaine that is presumably adulterated. The importance of accurately identifying levamisole-induced complications is therefore critical for symptomatic patients as discontinuation of exposure is fundamental and as a correct diagnosis prevents unnecessary and potentially dangerous use of other treatment modalities like powerful immunosuppressive therapy. Literature review suggests that levamisole might have the advantages of enhancing noradrenergic neurotransmission by inhibiting reuptake, by inhibiting MAO and/or COMT, by acting on ganglionic nicotinic receptors and by being partially metabolized into an amphetamine-like compound. It could also increase endogenous opioids and increase dopamine concentration in the cerebral reward pathway. These potential effects make levamisole an interesting choice as a cocaine adulterant. It seems unlikely that levamisole use as a cocaine adulterant will soon reach an end. More information is needed about the diagnosis and treatment of levamisole-induced complications, and the efforts of the medical and public health community is needed to face this challenging problem.

Immune-mediated agranulocytosis caused by the cocaine adulterant levamisole: a case for reactive metabolite(s) involvement

The United States Public Health Service Administration is alerting medical professionals that a substantial percentage of cocaine imported into the United States is adulterated with levamisole, a veterinary pharmaceutical that can cause blood cell disorders such as severe neutropenia and agranulocytosis. Levamisole was previously approved in combination with fluorouracil for the treatment of colon cancer; however, the drug was withdrawn from the U.S. market in 2000 because of the frequent occurrence of agranulocytosis. The detection of autoantibodies such as antithrombin (lupus anticoagulant) and an increased risk of agranulocytosis in patients carrying the human leukocyte antigen B27 genotype suggest that toxicity is immune-mediated. In this perspective, we provide an historical account of the levamisole/cocaine story as it first surfaced in 2008, including a succinct review of levamisole pharmacology, pharmacokinetics, and preclinical/clinical evidence for levamisole-induced agranulocytosis. Based on the available information on levamisole metabolism in humans, we propose that reactive metabolite formation is the rate-limiting step in the etiology of agranulocytosis associated with levamisole, in a manner similar to other drugs (e.g., propylthiouracil, methimazole, captopril, etc.) associated with blood dyscrasias. Finally, considering the toxicity associated with levamisole, we propose that the 2,3,5,6-tetrahydroimidazo[2,1-b]thiazole scaffold found in levamisole be categorized as a new structural alert, which is to be avoided in drug design.

Agranulocytosis and other consequences due to use of illicit cocaine contaminated with levamisole

PURPOSE OF REVIEW

Most of the illicit cocaine consumed in the United States and elsewhere is contaminated with levamisole, a veterinary medication. Agranulocytosis caused by levamisole exposure through cocaine abuse was first described in 2009. Since then, levamisole has also been shown and is known to cause vascular and neurologic complications. In this review, we provide an overview of the medical consequences of exposure to levamisole from adulterated cocaine.

RECENT FINDINGS

Within the past year, several new case series have deepened our understanding of the levamisole-agranulocytosis vasculopathy syndrome. The common nature of this exposure has been delineated, cocaine contaminated with levamisole. Significant controversy surrounds the role of granulocyte colony stimulating factor (GCSF) in levamisole-associated agranulocytosis.

SUMMARY

More than three fourths of cocaine users in the United States are exposed to levamisole; a significant minority of these individuals will develop autoimmune-mediated neutropenia, cutaneous vascular complications, and/or leukoencephalopathy. Levamisole exposure should be considered in the differential diagnosis of patients who present with these conditions in the setting of cocaine abuse. Neutropenia appears to resolve rapidly with cessation of exposure, so that GCSF therapy and a work-up for other causes may not be needed in all patients.

Levamisole exposure and hematologic indices in cocaine users

OBJECTIVES

Levamisole is an antihelminthic agent found in nearly 70% of seized U.S. cocaine. Sporadic case literature describes a life-threatening agranulocytosis associated with levamisole exposure secondary to cocaine use. The authors compared the distribution of hematologic indices in a population of cocaine users with and without a confirmed exposure to levamisole.

METHODS

The records of all patients in the Lifespan hospital system who underwent comprehensive toxicologic testing between September 2009 and December 2009 (n = 799) were reviewed. Of these, 95 patients were eligible for inclusion (cocaine-positive with a simultaneous complete blood count). Patients were grouped into levamisole-positive (n = 47) and -negative (n = 48) groups. The primary outcome measures were total white blood cell count (WBC), absolute neutrophil count (ANC), and absolute lymphocyte count (ALC); secondary outcome measures included percent neutrophils, lymphocytes, eosinophils, monocytes, and basophils, as well as identified co-ingestants.

RESULTS

Both groups had a similar makeup of age, sex, and race. The total WBC count, ANC, and ALC were not significantly different between the two groups. There was no significant difference in relative proportion of neutrophils, eosinophils, basophils, or monocytes between the groups. There was one neutropenic patient in the levamisole-positive group, while three patients were neutropenic in the negative group. Additionally, a literature review of case reports describing levamisole-induced agranulocytosis (n = 33) was conducted. In 52% of these cases, patients presented with an oropharyngeal chief complaint; in an additional 27%, patients presented with soft tissue infections or purpura.

CONCLUSIONS

The overall incidence of neutropenia was 4.2% in all cocaine users and 2.1% in the levamisole-positive group. A striking number of the reported patients with levamisole-associated neutropenia have presented to care with oropharyngeal complaints, vasculitis, or fever. A clinical algorithm for identifying levamisole toxicity in the emergency department setting is provided. Further research is necessary to determine the circumstances required for levamisole-associated neutropenia.

Contaminated cocaine and antineutrophil cytoplasmic antibody-associated disease

BACKGROUND AND OBJECTIVES

Approximately 70% of illicit cocaine consumed in the United States is contaminated with levamisole. Most commonly used as a veterinary antihelminthic agent, levamisole is a known immunomodulating agent. Prolonged use in humans has been associated with cutaneous vasculitis and agranulocytosis. We describe the development of a systemic autoimmune disease associated with antineutrophil cytoplasmic antibodies (ANCA) in cocaine users. This complication appears to be linked to combined cocaine and levamisole exposure.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Cases were identified between March 2009 and November 2010 at Massachusetts General Hospital's ANCA laboratory. Cocaine exposure was identified from patient history in all cases. Medical records were reviewed for clinical presentation and for laboratory and diagnostic evaluation.

RESULTS

Thirty cases of ANCA positivity associated with cocaine ingestion were identified. All had antimyeloperoxidase antibodies and 50% also had antiproteinase 3 antibodies. Complete clinical and laboratory data were available for 18 patients. Arthralgia (83%) and skin lesions (61%) were the most frequent complaints at presentation. Seventy-two percent of patients reported constitutional symptoms, including fever, night sweats, weight loss, or malaise. Four patients had biopsy-proven vasculitis. Two cases of acute kidney injury and three cases of pulmonary hemorrhage occurred. From the entire cohort of 30, two cases were identified during the first 3 months of our study period and nine cases presented during the last 3 months.

CONCLUSIONS

We describe an association between the ingestion of levamisole-contaminated cocaine and ANCA-associated systemic autoimmune disease. Our data suggest that this is a potentially life-threatening complication of cocaine use.

Aminorex poisoning in cocaine abusers

Levamisole is found in more than 80% of illicit cocaine seized within United States borders. Percentages are somewhat lower in Europe. In 2009, controlled in vivo studies demonstrated that horses metabolize levamisole to aminorex. Earlier this year our laboratory demonstrated that the same conversion occurs in man. Levamisole itself causes aplastic anemia and numerous reports have begun to appear in the literature, but the conversion of levamisole to aminorex is of much more concern. Aminorex ingestion was responsible for a five-year epidemic (1967-1972) of idiopathic pulmonary hypertension (IPH) confined to Switzerland, Austria, and Germany, the only countries where aminorex had been marketed as an anorectic. The incidence of IPH reverted to normal levels as soon as aminorex was withdrawn. In most cases onset of symptoms in IPH began after six to nine months of aminorex use, with average dosage ranges of 10 to 40 mg per day. The outcome was almost uniformly fatal. The conversion rate of levamisole to aminorex has not been established, but given the high daily intake of cocaine by many abusers, it seems likely that many of them will have ingested enough contaminated cocaine to ultimately cause IPH. Until the disease is well established, the symptoms of IHP are vague, and existing drug registries specifically exclude drug abusers, making it difficult to track these cases. This review is intended to draw attention to what may be a slowly emerging new epidemic.

Haematological toxicity of clozapine and some other drugs used in psychiatry

OBJECTIVE

To review recent work on the haematological toxicity of clozapine and some other drugs used in psychiatry concerning especially (i) the mechanism of antipsychotic-induced neutropenia/agranulocytosis, (ii) criteria for clozapine prescribing in benign ethnic neutropenia, (iii) options in the event of worrying falls in white cell count (WCC), including measures to boost WCC with or without continued clozapine administration, (iv) criteria for clozapine rechallenge in the event that treatment was suspended because of a fall in WCC and (v) safety concerns regarding clozapine in children/adolescents.

CONCLUSIONS

There remain several difficult areas, including the criteria for clozapine rechallenge. Experience has emphasised (i) the role of appropriate timing of WCC sample collection to ensure that clozapine is not withdrawn unnecessarily and (ii) the success of agents such as filgrastim in promoting rapid production of granulocytes if the situation so demands. On the other hand, the use of lithium to promote a leucocytosis has taken hold without a clear risk: benefit analysis. Be this as it may, should patients decide that they no longer wish to undergo WCC monitoring after 12 months on clozapine, cessation of monitoring is probably preferable to stopping the drug since overall mortality is decreased in patients treated with clozapine.