Disulfiram neuropathy: two cases of distal axonopathy

Use of Neuromuscular Ultrasound in the Diagnosis of Disulfiram Polyneuropathy

ABSTRACT

We present the case of a 37-year-old woman with alcohol use disorder, who developed leg cramping, bilateral foot drop, and hand weakness 3 months after starting disulfiram. This was accompanied by an 18-pound involuntary weight loss. Electrophysiologic findings showed a motor predominant axonal neuropathy. Neuromuscular ultrasound showed normal to small cross-sectional area of all nerves studied. This case is discussed, and the ultrasound findings are compared with another reported case.

Repositioned Drugs for COVID-19-the Impact on Multiple Organs

This review summarizes published findings of the beneficial and harmful effects on the heart, lungs, immune system, kidney, liver, and central nervous system of 47 drugs that have been proposed to treat COVID-19. Many of the repurposed drugs were chosen for their benefits to the pulmonary system, as well as immunosuppressive and anti-inflammatory effects. However, these drugs have mixed effects on the heart, liver, kidney, and central nervous system. Drug treatments are critical in the fight against COVID-19, along with vaccines and public health protocols. Drug treatments are particularly needed as variants of the SARS-Cov-2 virus emerge with some mutations that could diminish the efficacy of the vaccines. Patients with comorbidities are more likely to require hospitalization and greater interventions. The combination of treating severe COVID-19 symptoms in the presence of comorbidities underscores the importance of understanding the effects of potential COVID-19 treatments on other organs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s42399-021-00874-8.

Comparative effects of Mancozeb and Disulfiram-induced striated muscle myopathies in Long-Evans rats

Dithiocarbamates (DTCs) like mancozeb (MZ) and disulfiram (DS) are used throughout agriculture and medicine and have been implicated in neurotoxicity. Little research has been studied on the reported myopathies caused by these compounds. Their pathogenesis and mechanism of muscle toxicity has not been fully studied. The aim of this study is to investigate if DTCs alter striated muscle tissues in vivo. Long-Evans rats were treated with either MZ or DS followed by analysis of muscle biomarkers and metal levels. DS resulted in increases in serum lactate dehydrogenase (LDH), cardiac troponin, and myoglobin levels. Creatine kinase-MB serum levels decreased. Mancozeb only showed an increase in serum LDH. Both MZ and DS-treatment resulted in altered metal levels in the myocardium but not skeletal muscle. Ultrastructural alterations included damaged mitochondria and myofibril splitting. The presence of multivesicular bodies, and alterations of the intercalated disc were also seen.

Evaluation of the accumulation of disulfiram and its copper complex in A549 cells using mass spectrometry

The famous alcohol-aversion drug disulfiram (DSF) is a promising candidate for repurposing in cancer therapy, as indicated by many ongoing and completed clinical trials. Existing researches focus on demonstrating that the anti-cancer activity of DSF is enhanced by copper ions, or solving the problem that DSF is easily decomposed in the body to lose its activity. However, the metabolic kinetics of its ultimate anti-cancer metabolite DDC-Cu (bis-diethyldithiocarbamate-copper) in cells and how it exerts anti-cancer mechanisms remain unclear. In this work, mass spectrometric evaluation of the intracellular and extracellular accumulation of DSF and its copper complex DDC-Cu was performed. Combined with cytotoxicity assay, staining analysis and flow cytometry, we found that DDC-Cu could easily pass through the cell membrane of A549 cells, and accumulate intracellularly for a long time. This process can lead to cellular morphological changes, an increase in ROS content, cell cycle arrest in the G0/G1 phase and apoptosis. Besides, molecular cancer-relevant targets of DDC-Cu in cancer cells were further discussed. This work investigated the cytotoxic mechanism of DDC-Cu, which has important clinical significance for its application in cancer therapy.

A Comparative Review of Chemotherapy-Induced Peripheral Neuropathy in In Vivo and In Vitro Models

Chemotherapy-induced peripheral neuropathy (CIPN) is an adverse effect caused by several classes of widely used anticancer therapeutics. Chemotherapy-induced peripheral neuropathy frequently leads to dose reduction or discontinuation of chemotherapy regimens, and CIPN symptoms can persist long after completion of chemotherapy and severely diminish the quality of life of patients. Differences in the clinical presentation of CIPN by widely diverse classifications of anticancer agents have spawned multiple mechanistic hypotheses that seek to explain the pathogenesis of CIPN. Despite its clinical relevance, common occurrence, and extensive investigation, the pathophysiology of CIPN remains unclear. Furthermore, there is no unequivocal gold standard for the prevention and treatment of CIPN. Herein, we review in vivo and in vitro models of CIPN with a focus on histopathological changes and morphological features aimed at understanding the pathophysiology of CIPN and identify gaps requiring deeper exploration. An elucidation of the underlying mechanisms of CIPN is imperative to identify potential targets and approaches for prevention and treatment.

Cell cycle specific radiosensitisation by the disulfiram and copper complex

The disulfiram and copper complex (DSF:Cu) has emerged as a potent radiosensitising anti-cancer agent. The ability of copper to stabilise DSF in a planar conformation and to inhibit DNA replication enzymes stimulated our investigation of the effect of DSF:Cu on cell cycle regulation. Flow cytometry and immunoblotting were used to assess the effect of DSF:Cu on cell cycle progression of the neuroblastoma cell line SK-N-BE(2c) and the glioma cell line UVW. Treatment with 0.1 and 0.3 μM DSF:Cu inhibited DNA synthesis in SK-N-BE(2c) and UVW cells, respectively. The increased potency of ionising radiation treatment induced by DSF:Cu and/or gemcitabine was determined by clonogenic assay. Treatment with 0.3 μM DSF:Cu resulted in greater radiation kill, exemplified by dose enhancement factor values of 2.64 and 2.84 in SK-N-BE(2c) and UVW cells, respectively. Although DSF:Cu failed to sensitise S phase cells to irradiation, we observed that DSF:Cu radiosensitisation was potentiated by the S phase-specific cytotoxic drug gemcitabine. The efficacy of the combination treatment consisting of DSF:Cu, gemcitabine and ionising radiation was schedule-dependent. Together, these results describe cell cycle specific radiosensitisation by DSF:Cu. The well-established toxicity profiles of DSF and gemcitabine should facilitate their evaluation as a combination treatment in patients undergoing radiotherapy.

Sensory-motor axonal polyneuropathy involving cranial nerves: An uncommon manifestation of disulfiram toxicity

Disulfiram (tetraethylthiuram disulfide) has been used for the treatment of alcohol dependence. An axonal sensory-motor polyneuropathy with involvement of cranial pairs due to disulfiram is exceedingly rare. The authors report a unique case of an extremely severe axonal polyneuropathy involving cranial nerves that developed within weeks after a regular dosage of 500mg/day disulfiram. To the authors best knowledge, such a severe and rapidly-progressive course has never been described with disulfiram dosages of only 500mg/day.

Disulfiram neuropathy: two case reports

Background

Neuropathy is a rare adverse side effect of disulfiram therapy and is under-recognized. There have been few case reports documenting this side effect.

Case presentation

Two cases of disulfiram peripheral neuropathy are discussed. The first case is that of a 25-year-old Caucasian woman who was exposed to disulfiram therapy for a total of 8 months and developed pain and stiffness that prevented her from walking. The second case is that of a 46-year-old Caucasian woman who developed sudden-onset numbness in her lower extremities with progression to pain. Her symptoms improved over the course of 2 months after cessation of disulfiram therapy. In both cases, symptoms improved after cessation of disulfiram therapy.

Conclusions

Disulfiram neuropathy occurs in persons with a history of chronic alcohol use. It is under-recognized and often attributed to alcoholic neuropathy given its comorbidity with alcoholic neuropathy. A greater understanding of this side effect may reduce neurologic complications related to disulfiram neuropathy and aid in early withdrawal of this offending agent.

Alcohol use disorders and current pharmacological therapies: the role of GABA(A) receptors

Alcohol use disorders (AUD) are defined as alcohol abuse and alcohol dependence, which create large problems both for society and for the drinkers themselves. To date, no therapeutic can effectively solve these problems. Understanding the underlying mechanisms leading to AUD is critically important for developing effective and safe pharmacological therapies. Benzodiazepines (BZs) are used to reduce the symptoms of alcohol withdrawal syndrome. However, frequent use of BZs causes cross-tolerance, dependence, and cross-addiction to alcohol. The FDA-approved naltrexone and acamprosate have shown mixed results in clinical trials. Naltrexone is effective to treat alcohol dependence (decreased length and frequency of drinking bouts), but its severe side effects, including withdrawal symptoms, are difficult to overcome. Acamprosate showed efficacy for treating alcohol dependence in European trials, but two large US trials have failed to confirm the efficacy. Another FDA-approved medication, disulfiram, does not diminish craving, and it causes a peripheral neuropathy. Kudzu is the only natural medication mentioned by the National Institute on Alcohol Abuse and Alcoholism, but its mechanisms of action are not yet established. It has been recently shown that dihydromyricetin, a flavonoid purified from Hovenia, has unique effects on GABAA receptors and blocks ethanol intoxication and withdrawal in alcoholic animal models. In this article, we review the role of GABAA receptors in the treatment of AUD and currently available and potentially novel pharmacological agents.

Targeting aldehyde dehydrogenase 2: new therapeutic opportunities

A family of detoxifying enzymes called aldehyde dehydrogenases (ALDHs) has been a subject of recent interest, as its role in detoxifying aldehydes that accumulate through metabolism and to which we are exposed from the environment has been elucidated. Although the human genome has 19 ALDH genes, one ALDH emerges as a particularly important enzyme in a variety of human pathologies. This ALDH, ALDH2, is located in the mitochondrial matrix with much known about its role in ethanol metabolism. Less known is a new body of research to be discussed in this review, suggesting that ALDH2 dysfunction may contribute to a variety of human diseases including cardiovascular diseases, diabetes, neurodegenerative diseases, stroke, and cancer. Recent studies suggest that ALDH2 dysfunction is also associated with Fanconi anemia, pain, osteoporosis, and the process of aging. Furthermore, an ALDH2 inactivating mutation (termed ALDH2*2) is the most common single point mutation in humans, and epidemiological studies suggest a correlation between this inactivating mutation and increased propensity for common human pathologies. These data together with studies in animal models and the use of new pharmacological tools that activate ALDH2 depict a new picture related to ALDH2 as a critical health-promoting enzyme.

Tau hyperphosphorylation and axonal damage induced by N,N-diethyldithiocarbamate (DEDTC) treatment along late postnatal development is followed by a rescue during adulthood

Axonal degeneration has been described as the pathological hallmark of peripheral neuropathies induced by DEDTC. In addition, axonal damage has also been observed in the brain of mice treated daily with DEDTC along postnatal development, though with this experimental model there was observed to be axonal recovery after treatment, during the adulthood. To focus on this axonal dynamic activity, damage-recovery, a key axonal protein, the microtubule associated protein tau, was analyzed in this DEDTC model. Tau is a phosphoprotein and its dynamic site-specific phosphorylation is essential for its proper function; in fact, high levels are correlated with cell dysfunction. Furthermore, the levels of tau phosphorylation are associated with dynamic microtubules during periods of high plasticity. Thus, phosphorylated tau at two sites of phosphorylation, Ser(199) and Ser(396), were evaluated during the second week of postnatal development and throughout adulthood. The results obtained by Western blot made it evident that the levels of p-tau Ser(199) and p-tau Ser(396) were higher in treated mice than in controls. Interestingly, by immunohistochemistry there was shown to be an increase in p-tau-immunolabeling in neuronal soma together with axonal tract alterations in treated animals with respect to controls, and the analyses of GSK3 beta and cdk5 revealed an increase in its activity in DEDTC-treated animals. Nevertheless, in the adult a general decline in p-tau was observed together with a rescue of axonal tract. All these data support the idea that the axonal damage induced by DEDTC treatment along postnatal development is followed by an axonal rescue during adulthood.