Evaluation of drug resistance to albendazole and levamisole against lung worms in goat flocks based on fecal larvae count reduction test

The over-use of anti-parasitic compounds as a method of control has led to insufficient effectiveness and widespread drug resistance worldwide. The aim of this study was to investigate the efficacy of albendazole and levamisole as anti-parasitic agents in a lung worm control program in goat flocks. During 2021 and 2022, a total of 110 goats (age of four months and above) were randomly selected from 11 herds in the north-western region of Iran including Saanen breed (both sexes of the same age). The results indicated that 3.60, 50.80 and 41.90% were respectively infected with Dictyocaulus filaria, Muellerius capillaris and Proto-strongylus rufescens, and generally all the lung parasites in goats of this region were resistant to albendazole and levamisole. Due to clinical importance of D. filaria in goats, the molecular analysis of two samples was also done. Sequencing results showed that the identified parasites were 100% similar to the reference sequences registered in the GenBank®. The results of this research showed low level of these anthelmintics efficacy against Dictyocaulus and Muellerius. Generally, the lung parasites in goats of this region are resistant to albendazole and levamisole. The P. rufescens showed high resistance to these drugs. Totally, it can be concluded that the level of drug resistance varies in different parts of the world; but, the frequencies of drug resistance in different parts of the world are not the same, requiring more studies.

Antineutrophil cytoplasmic antibody in children with nephrotic syndrome treated with levamisole: a cross-sectional cohort study

BACKGROUND

Levamisole is a commonly used steroid-sparing agent (SSA), but the reported incidence of antineutrophil cytoplasmic antibody (ANCA) positivity has been concerning.

METHODS

Observational cross-sectional study wherein children aged 2 to 18 years with frequently relapsing/steroid dependent nephrotic syndrome (FRNS/SDNS) on levamisole for ≥ 12 months were tested for ANCA.

RESULTS

A total of 210 children (33% female), median age of 7.3 (IQR: 5.6-9.6) years, and a median duration of levamisole exposure of 21 (IQR: 15-30) months were tested. ANCA was positive in 18% (n = 37): 89% (n = 33) perinuclear ANCA (pANCA), 3% (n = 1) cytoplasmic ANCA (cANCA), and 8% (n = 3) both. Of ANCA-positive children, none had reduced eGFR or abnormal urinalysis. The majority of these children were asymptomatic (81%, n = 30). Rash was more common among ANCA-positive children [6/37 (16%) vs. 3/173 (2%), p = 0.0001]. On multivariate analysis, higher age (OR = 1.02, [95th CI: 1.01 to 1.03], p = 0.007) and longer duration of levamisole exposure (OR = 1.05, [95th CI: 1.02 to 1.08], p = 0.0007) were associated with ANCA positivity. Levamisole was stopped in ANCA-positive children with the resolution of any clinical manifestations if present. Repeat ANCA testing was performed in 54% (20/37), and all were ANCA negative by 18 months.

CONCLUSIONS

Children with FRNS/SDNS on longer duration of levamisole were associated with increasing prevalence of ANCA positivity, but most of these children were clinically asymptomatic. Prospective studies are required to determine the chronology of ANCA positivity and its clinical implication.

The proof is in the poo-ding: Benefits of the longitudinal molecular surveillance of drug resistance demonstrated in a New South Wales cattle herd

Our understanding of anthelmintic resistance in the gastrointestinal nematodes of Australian cattle relies exclusively on small-scale phenotypic reports utilising traditional faecal egg count reduction tests. This approach is not readily scalable to establish the national prevalence of resistance, nor is it conducive of routine longitudinal surveillance for the emergence of resistance in its early stages. This study introduces the benefits of applying mixed amplicon metabarcoding longitudinally for timely and cost-efficient molecular surveillance of multiple anthelmintic resistance mutations, as they emerge on farms. Using opportunistically collected faecal samples from a cattle herd in central west New South Wales (2019-2023), we detected the early emergence of Haemonchus spp. levamisole-resistant S168T shortly after levamisole introduction, while benzimidazole-resistant allele frequencies remained constant. Additionally, we observed the possible spill-over of resistant Haemonchus contortus from sheep, along with variations in faecal burdens and species diversity influenced by climate stochasticity and host immunity. This study emphasises the power of molecular diagnostics for farm-level anthelmintic resistance management, providing essential evidence to support its integration into routine surveillance programmes.

Imaging of Drug-Related Vasculopathy

Illicit and recreational drugs, such as cocaine, heroin, amphetamines, and marijuana, can result in drug-related vasculitis or vasculopathy. Similarly, the use of certain antithyroid, oncologic, and immunosuppressive medications for therapeutic purposes can lead to vasculopathy. This in turn may result in significant complications in the central nervous system, including intracranial hemorrhage and stroke. Cocaine abuse can also lead to midline destructive lesions of the sinonasal complex. MR imaging, Vessel Wall imaging, and CT/CTA are valuable imaging tools for the evaluation of patients with suspected drug-induced vasculopathy or vasculitis. This article reviews the pathomechanism, clinical presentation, and imaging findings of vasculopathy related to drug abuse and prescribed medications.

Real-time single-base specific detection of the Haemonchus contortus S168T variant associated with levamisole resistance using loop-primer endonuclease cleavage loop-mediated isothermal amplification

Haemonchus contortus is a parasitic haematophagous nematode that primarily affects small ruminants and causes significant economic loss to the global livestock industry. Treatment of haemonchosis typically relies on broad-spectrum anthelmintics, resistance to which is an important cause of treatment failure. Resistance to levamisole remains less widespread than to other major anthelmintic classes, prompting the need for more effective and accurate surveillance to maintain its efficacy. Loop-primer endonuclease cleavage loop-mediated isothermal amplification (LEC-LAMP) is a recently developed diagnostic method that facilitates multiplex target detection with single nucleotide polymorphism (SNP) specificity and portable onsite testing. In this study, we designed a new LEC-LAMP assay and applied it to detect the levamisole resistance marker S168T in H. contortus. We explored multiplexing probes for both the resistant S168T and the susceptible S168 alleles in a single-tube assay. We then included a generic probe to detect the acr-8 gene in the multiplex assay, which could facilitate the quantification of both resistance markers and overall genetic material from H. contortus in a single step. Our results showed promising application of these technologies, demonstrating a proof-of-concept assay which is amenable to detection of resistance alleles within the parasite population, with the potential for multiplex detection, and point-of-care application enabled by lateral flow end-point detection. However, further optimisation and validation is necessary.

Monitoring levamisole in food and the environment with high selectivity using an electrochemical chiral sensor comprising an MOF and molecularly imprinted polymer

We used an enhanced recognition strategy to fabricate a novel levamisole-detecting chiral electrochemical sensor featuring a metal-organic framework (MOF) combined with a molecularly imprinted polymer (MIP). We first synthesised a Cu/Zn-[benzene-1,3,5-tricarboxylic acid] (Cu/Zn-BTC) MOF as the molecular immobilisation and signal-amplifying unit, and then prepared the MIP (molecular recognition unit) using levamisole as the template on a glassy carbon electrode modified with Cu/Zn-BTC. We obtained a composite chiral sensor with enhanced recognition capability for levamisole after template removal. Using the templated sites as the switch and K3[Fe(CN)6]/K4[Fe(CN)6] as a probe, we established a new method for detecting levamisole in meat products and water bodies. The linear detection range and detection limit of our chiral sensor are 5 to 6000 × 10-11 mol/L and 1.65 × 10-12 mol/L, respectively. Moreover, the sensor exhibited 93.8-109.0% recovery in the detection of levamisole in chicken and other real samples.

The potential immunomodulatory effect of levamisole in humans and farm animals

This study conducted a literature review to investigate the immunomodulatory effect of levamisole in both humans and farm animals. The following procedure was followed for database searching: PubMed, Google Scholar, Web of Science, and Cochrane Library. All research works were updated to September 2022. The terms used in the literature search were included: ("levamisole" OR "immunity" OR "immune system") AND ("adjuvant" OR "fish" OR "poultry" OR "farm animal" OR "cattle" OR "sheep"). The current review enlightens the extensive potential of levamisole as an adjuvant immunotherapeutic agent and explains its divergent applications beyond its antiparasitic use as an adjuvant, dietary supplement, immunostimulant, antiviral, and anti-cancer drug in humans and farm animals. In the articles examined, various mechanisms have been proposed for levamisole immunoprotective effects, but hormonal alteration and stress hormone reduction are indicated as the main mechanisms in various animal species.

Simultaneous analysis of the of levamisole with triclabendazole in pharmaceuticals through developing TLC and HPLC-PDA chromatographic techniques and their greenness assessment using GAPI and AGREE methods

Two simple and rapid chromatographic methods were developed and validated for the analysis of levamisole and triclabendazole simultaneously in pure and pharmaceutical products. The first method is thin-layer chromatography (TLC) with densitometry, and the second method is high-performance liquid chromatography with PDA detection (HPLC-PDA). A Hypersil BDS C18 column with dimensions of 4.6 × 150 mm and a particle size of 5 µm was used in the HPLC-PDA method. An isocratic condition was used to carry out the separation, and the mobile phase was made up of acetonitrile and a 0.03 M potassium dihydrogen phosphate buffer in double-distilled water. The ratio of the mobile phase preparation was 70:30 (v/v), and the flow rate was 1 mL/min. A wavelength of 215 nm was employed for analyte detection. Precoated silica gel 60 F254 aluminium plates were used for the TLC method's separation. Mobile phase was made of ethyl acetate, hexane, methanol, and ammonia (69:15:15:1) for the separation. The detection wavelength selected was 215 nm. According to the International Council for Harmonization (ICH) guidelines, the proposed methods were validated and it was found that the two chromatographic methods are accurate, precise, and linear for both compounds in the range of 3.75-37.5 and 6-60 mg/L for the HPLC method for levamisole and triclabendazole, respectively and in the range of 2-14 µg/spot for the TLC method. The developed methods greenness profile was assessed using AGREE and ComplexGAPI tools.

Efficacy in US cattle of a novel fixed-dose combination injectable (0.2 mg/kg doramectin + 6.0 mg/kg levamisole hydrochloride) against naturally acquired gastrointestinal nematode infections

Reports of macrocyclic lactone (ML) loss of efficacy suggest ML resistance in gastrointestinal nematodes (GINs) is a growing problem in the US cattle industry. Empirical and modeling data support combining an ML and second anthelmintic from a different drug class to help ML resistance development while effectively treating existing resistant parasite populations. Here, we present a novel fixed-dose combination injectable (FDCI) solution for cattle that delivers 0.2 mg of doramectin and 6.0 mg of levamisole hydrochloride (HCl) per kg of body weight. Field studies were conducted at six sites across the Midwest United States to investigate the efficacy of a single administration of the FDCI in treating common cattle GINs. Cattle (n = 425) with GIN infections confirmed by fecal egg count (FEC) on Day -10( ± 2) were randomly allocated to the control (saline) or treatment (FDCI) group. On Day 0, pre-treatment fecal samples were collected, and cattle were administered a single subcutaneous injection of saline (n = 106) or FDCI (n = 319). Post-treatment fecal samples were collected on Day 14. Fecal egg count reduction tests (FECRTs) were conducted using Day 0 and Day 14 FECs. Efficacy was evaluated using Day 14 FECs (FDCI-treated versus saline-treated). Within treatment, samples collected on Days 0 and 14 with ≥ 20 eggs per gram (EPG) were cultured for nematode larvae recovery and identification. Day -10 FECs for enrolled animals were similar between treatment groups. Coprocultures from cattle with FEC ≥ 20 EPG (n = 68 saline; n = 211, FDCI) on Day 0 showed the presence of Cooperia punctata, Ostertagia spp., Haemonchus spp., C. oncophora, Oesophagostomum spp. and Trichostrongylus spp. Day 14 FECs for FDCI-treated cattle were significantly reduced (0-3 EPG) compared to saline-treated cattle (0-1252 EPG) (p ≤ 0.0042). At all study sites, the efficacy of the new FDCI was ≥ 99.4% and the FECR was 0.99 or 1.00. Day 14 coprocultures from control cattle showed infections of common GIN genera, confirming the efficacy of the FDCI against GINs in the field. A single administration of the doramectin + levamisole HCl combination injectable effectively treats common and economically important cattle GINs.

Efficacy of a fixed-dose combination injectable (0.2 mg/kg doramectin + 6.0 mg/kg levamisole hydrochloride) in New Zealand cattle against naturally acquired gastrointestinal nematode populations with demonstrated resistance to doramectin

Intensive farming practices and heavy reliance on anthelmintics have contributed significantly to the problem of macrocyclic lactone (ML) resistance in New Zealand. Farmers now have few options for effectively controlling cattle gastrointestinal nematodes (GINs) and regularly experience sub-optimal efficacy against economically important species. We present a novel fixed-dose combination injectable (FDCI) that simultaneously delivers 0.2 mg/kg doramectin and 6 mg/kg levamisole hydrochloride (HCl) to target a broad spectrum of cattle GINs in a single dose, providing an additional solution to endoparasite control in an environment of anthelmintic resistance. A dose confirmation study was conducted using naturally acquired infections of GINs in beef cattle in New Zealand. Cattle with GIN infections confirmed by fecal egg count (FEC) were randomly allocated (n = 12 per group) to the control (saline-treated), FDCI-treated or doramectin-treated group. On Day 0, cattle were weighed and administered a single subcutaneous injection of saline or endectocide. Rectal fecal samples were collected from each animal on Day 7 for individual duplicate fecal egg count (FEC) analysis, and coprocultures were conducted on pooled fecal samples within each treatment group. All animals were euthanized and necropsied for worm recovery on Days 14 through 16. Treatment efficacy was calculated based on reduction in FECs and worm burdens. All enrolled cattle were positive for GINs based on Day -5 FECs, with geometric mean (GM) FECs ranging from 337 to 521 eggs per gram (EPG). All saline-treated cattle remained positive for GIN infections for the study duration (Day 7 GM FEC = 427 EPG). Necropsy and worm recoveries revealed the presence of doramectin-resistant Cooperia oncophora, C. surnabada and Trichostrongylus longispicularis, as evidenced by ≤ 72.3 % efficacy of doramectin against these species. The new FDCI was ≥ 99.8 % effective against all GIN species, including ML-resistant C. oncophora, C. surnabada and T. longispicularis, providing broad-spectrum efficacy and eliminating economically important cattle GINs, including ML-resistant populations.

Comparative growth performance of backgrounded beef heifers treated with an injectable fixed-dose combination (0.2 mg/kg doramectin + 6.0 mg/kg levamisole hydrochloride) or single-active (0.2 mg/kg ivermectin) endectocide

Gastrointestinal nematodes (GINs) can negatively impact all production classes of cattle, particularly growing cattle. A global decline in efficacy of broad-spectrum single-active anthelmintics requires alternative GIN control methods without the aid of novel drug classes. Here, we present a new fixed-dose combination injectable (FDCI) endectocide for cattle that combines doramectin (5 mg/ml) and levamisole hydrochloride (150 mg/ml). A 56-day comparative performance confinement backgrounding trial was conducted in stocker beef heifers (n = 1548) with confirmed GIN infections to (1) compare the Day 14 post-treatment effectiveness of the new FDCI endectocide to pen mates treated with the injectable single-active endectocide ivermectin, as evidenced by fecal egg counts (FECs) conducted for a randomly selected subset (10%) of both treatment groups, and (2) determine if the greater GIN control by the FDCI evidenced in the subsample improved growth performance in all FDCI-treated heifers. Heifers were procured in four cohorts, with a 10-week timeframe between enrollment of the first and last cohort. Treatment groups were comingled within dirt-floor pens (n = 31; 7-8 per cohort) and offered a standard backgrounding diet ad libitum for the study duration. Heifers with enrollment FEC ≥ 30 eggs per gram (EPG) were randomly allocated to receive the FDCI (n = 773) or ivermectin (n = 775) on Day 0. Day 0 FECs conducted on 10% of enrolled heifers (FDCI, n = 78; ivermectin, n = 79) were not different between treatment groups (p = 0.491). Day 14 FECs for the same heifers were reduced compared to Day 0 within each treatment group. Heifers given the FDCI had lower Day 14 AM FECs and higher FEC reduction test (FECRT) result (0.07 EPG; 0.999) than ivermectin-treated heifers (21.58 EPG; FECRT = 0.850). Mean body weight (BW) was not different between treatment groups on Day 0 (p = 0.2762) and Day 14 (p = 0.2010) but was significantly greater (p = 0.0007) for FDCI-treated heifers compared to ivermectin-treated heifers on Day 56. Compared to ivermectin-treated heifers, overall average daily gain from all evaluation periods (Day 0-14, Day 14-56, and Day 0-56) was greater (p ≤ 0.0052) in FDCI-treated heifers, and FDCI-treated heifers had 4.223 kg greater total weight gain over the 56-day study. The FDCI (0.2 mg/kg doramectin + 6.0 mg/kg levamisole hydrochloride) was highly effective in reducing GIN infections and thus promoted improved growth performance in beef heifers over a 56-day backgrounding period.

Levamisole suppresses activation and proliferation of human T cells by the induction of a p53-dependent DNA damage response

Levamisole (LMS) is a small molecule used in the treatment of idiopathic nephrotic syndrome (INS). The pathogenesis of INS remains unknown, but evidence points toward an immunological basis of the disease. Recently, LMS has been shown to increase the relapse-free survival in INS patients. While LMS has been hypothesized to exert an immunomodulatory effect, its mechanism of action remains unknown. Here, we show that LMS decreased activation and proliferation of human T cells. T-cell activation-associated cytokines such as IL-2, TNF-α, and IFN-γ were reduced upon LMS treatment, whereas IL-4 and IL-13 were increased. Gene expression profiling confirmed that the suppressive effects of LMS as genes involved in cell cycle progression were downregulated. Furthermore, genes associated with p53 activation were upregulated by LMS. In agreement, LMS treatment resulted in p53 phosphorylation and increased expression of the p53 target gene FAS. Accordingly, LMS sensitized activated T cells for Fas-mediated apoptosis. LMS treatment resulted in a mid-S phase cell cycle arrest accompanied by γH2AX-foci formation and phosphorylation of CHK1. Our findings indicate that LMS acts as an immunosuppressive drug that directly affects the activation and proliferation of human T cells by induction of DNA damage and the activation of a p53-dependent DNA damage response.

Reproductive and margin of safety of a fixed-dose combination injectable endectocide (0.2 mg/kg doramectin; 6.0 mg/kg levamisole hydrochloride) in cattle

We present a fixed-dose combination injectable (FDCI) solution for cattle formulated for a single subcutaneous administration at a dose rate of 1 ml/25 kg of body weight to deliver a dose of 0.2 mg/kg of doramectin and 6.0 mg/kg of levamisole hydrochloride (5.1 mg/kg base equivalent). This drug product is marketed in the United States under the tradename Valcor® and in Australia and New Zealand under the tradename Dectomax V®. Both levamisole and doramectin have histories of safe and effective use in ruminants, with safety margins of 3X and 25X, respectively. Three studies were conducted to demonstrate the safety of the new FDCI: margin of safety (Study 1), and reproductive safety in sexually nulliparous beef heifers (Studies 2 and 3). In Study 1, 3-month-old sexually intact male and female calves were given either saline (control) or 1X, 2X, or 3X FDCI on Days 0, 14, and 28. General health, clinical, and neurological observations were made throughout the study, and clinical and pathology evaluations were made at study end. Studies 2 and 3 demonstrated the reproductive safety of the FDCI on sexually nulliparous beef heifers using estrus synchronization and timed artificial insemination. Treatments of either saline (control) or 3X FDCI were administered to coincide with either folliculogenesis, implantation, organogenesis, early gestation, or late gestation. Reproductive safety was demonstrated by evaluating rates of conception, calving, abortion, and stillbirth, dystocia scores, and calf health. In all studies, the FDCI at 1X, 2X, or 3X dosages was well tolerated. In the margin of safety study, 3X calves showed increased incidence of salivation for up to 8 h post-dosing compared to other groups. Injection sites were palpable post-dosing in all three FDCI groups but resolved by Day 28 in all but one animal each in 2X and 3X. In the reproductive safety studies, the FDCI had no effect on conception, pregnancy, fetal development, or postnatal viability. Injection site swelling was increased in frequency and duration compared to controls. The studies demonstrate the safety of the new FDCI in cattle from 3 months of age and in reproducing heifers during all reproductive stages from folliculogenesis through gestation and up to a month post-partum.

Efficacy of a fixed-dose combination injectable (0.2 mg/kg doramectin + 6.0 mg/kg levamisole hydrochloride) in Australian cattle against naturally acquired gastrointestinal nematode infections

Australian producers have long used macrocyclic lactones (MLs) to successfully control cattle gastrointestinal nematodes (GINs) and consequently improve production parameters. However, the trajectory of ML resistance development in cattle GINs is following that of small ruminant nematode populations, highlighting a need for novel treatment options to provide efficacy in the current environment and interrupt the long-term establishment of ML-resistant GIN populations in Australian cattle. Here, we describe three field studies conducted in Australia to evaluate the efficacy of a single administration of a novel fixed-dose combination injectable (FDCI) endectocide against naturally acquired infections of cattle GINs. The FDCI is administered subcutaneously to deliver 0.2 mg/kg doramectin and 6 mg/kg levamisole hydrochloride (HCl). Study sites consisted of three farms in New South Wales (n = 2) and Victoria (n = 1). At each site, cattle were randomly allocated into one of three treatment groups: (1) untreated control (saline), (2) FDCI (0.2 mg/kg doramectin, 6 mg/kg levamisole HCl) or (3) positive control (0.2 mg/kg ivermectin). All treatments were administered on Day 0. Fecal samples were collected prior to treatment on Days -1 (Study 3) or 0 (Studies 1 and 2) and again on Day 14 (post-treatment) to evaluate efficacy via fecal egg count (FEC) and for coproculture. Adequacy of infection was confirmed at all three study sites, with Day 14 geometric mean (GM) FECs for saline-treated cattle ranging from 32.5 eggs per gram (EPG) to 623.7 EPG. FECs for FDCI-treated cattle were significantly reduced compared to saline-treated cattle (p ≤ 0.0001) on Day 14, with GM-based efficacy ≥ 99.7% at all three study sites. In contrast, ivermectin was 97.4% effective against cattle GINs in Study 1 but was only 47.2% and 39.8% effective at study site 2 and 3, respectively. Genus-specific efficacies suggest the presence of ivermectin-resistant Cooperia spp. (Study 1), Haemonchus spp. (Study 2) and Ostertagia spp. (Study 3) populations in the naturally infected cattle used in these studies. The post-treatment FEC and genus-specific efficacy estimations indicate the doramectin + levamisole HCl FDCI was highly efficacious against cattle GINs even in the face of ivermectin LOE at study sites 2 and 3. The efficacy of the new FDCI against both ML-susceptible and ML-resistant economically important cattle GINs in Australia affirms it is a valuable treatment option for producers operating in an environment of ML loss of efficacy.

Dose confirmation of a novel fixed dose combination injectable (0.2 mg/kg doramectin + 6.0 mg/kg levamisole hydrochloride) against naturally acquired gastrointestinal nematodes in US cattle

Macrocyclic lactone (ML) resistance in cattle gastrointestinal nematodes (GINs) is an increasing problem. Concurrent combination anthelmintic therapy incorporating an existing ML with a second drug class has been proposed to control cattle GINs while slowing the development of ML resistance. Two dose confirmation studies were conducted to investigate the efficacy of a new fixed-dose combination injectable (FDCI) anthelmintic against common cattle GINs known to negatively impact production. The FDCI is formulated with 5 mg/ml doramectin and 150 mg/ml levamisole hydrochloride (HCl). Cattle enrolled in the two studies were sourced from either the Southern (Study 1, n = 30) or Midwest (Study 2, n = 36) United States. Animals with GIN infections confirmed by fecal egg count (FEC) were randomly allocated to one of three treatment groups. On Day 0, cattle with positive FECs on Day -5( ± 2) were weighed and administered a single subcutaneous injection of either saline (0.9% sodium chloride) at 0.04 ml/kg, 10 mg/ml doramectin at 0.02 ml/kg (to provide 0.2 mg/kg doramectin) or the FDCI at 0.04 ml/kg (to provide 0.2 mg/kg doramectin and 6.0 mg/kg levamisole HCl). On Day 14, fecal samples were collected, animals were euthanized, and worms were collected from the intestinal tract of each animal. Treatment efficacy was calculated using worm burdens and the fecal egg count reduction test (FECRT). Pre-treatment (Day -5, Study 1; Day -3, Study 2) mean FECs were 999.4-1136.2 eggs per gram (EPG) in Study 1 and 137.1-226.6 EPG in Study 2. The FDCI was active against cattle GIN populations in both studies, with FECRT ≥ 99.98% in both studies. Compared to saline-treated cattle, FDCI-treated cattle had significantly fewer adult and immature worms of all identified species on Day 14. In Study 1, Day 14 efficacy of the FDCI was 96.9% for Cooperia spp. (C. oncophora (99.7%) and C. punctata (95.9%)), 99.1% for Nematodirus helvetianus, and 99.8% for Ostertagia spp. In Study 2, the FDCI provided 100% efficacy against all adult GIN species identified, including all GINs identified in Study 1 and Trichostrongylus axei. The FDCI also provided 95.5% efficacy against immature Ostertagia spp. and 100% efficacy against immature Cooperia spp. (Study 2). Doramectin was effective against all adult cattle GINs (except N. helvetianus) in Study 2 but was only effective against adult Ostertagia spp. in Study 1. Additionally, doramectin was only effective against immature Cooperia spp. (and not immature Ostertagia spp.) in Study 2. A single administration of the doramectin + levamisole HCl FDCI provides a new and effective approach to the treatment and control of common cattle GINs, including those exhibiting decreased susceptibility to doramectin alone.

The pipeline for drugs for control and elimination of neglected tropical diseases: 2. Oral anti-infective drugs and drug combinations for off-label use

In its 'Road map for neglected tropical diseases 2021-2030', the World Health Organization outlined its targets for control and elimination of neglected tropical diseases (NTDs) and research needed to achieve them. For many NTDs, this includes research for new treatment options for case management and/or preventive chemotherapy. Our review of small-molecule anti-infective drugs recently approved by a stringent regulatory authority (SRA) or in at least Phase 2 clinical development for regulatory approval showed that this pipeline cannot deliver all new treatments needed. WHO guidelines and country policies show that drugs may be recommended for control and elimination for NTDs for which they are not SRA approved (i.e. for 'off-label' use) if efficacy and safety data for the relevant NTD are considered sufficient by WHO and country authorities. Here, we are providing an overview of clinical research in the past 10 years evaluating the anti-infective efficacy of oral small-molecule drugs for NTD(s) for which they are neither SRA approved, nor included in current WHO strategies nor, considering the research sponsors, likely to be registered with a SRA for that NTD, if found to be effective and safe. No such research has been done for yaws, guinea worm, Trypanosoma brucei gambiense human African trypanosomiasis (HAT), rabies, trachoma, visceral leishmaniasis, mycetoma, T. b. rhodesiense HAT, echinococcosis, taeniasis/cysticercosis or scabies. Oral drugs evaluated include sparfloxacin and acedapsone for leprosy; rifampicin, rifapentin and moxifloxacin for onchocerciasis; imatinib and levamisole for loiasis; itraconazole, fluconazole, ketoconazole, posaconazole, ravuconazole and disulfiram for Chagas disease, doxycycline and rifampicin for lymphatic filariasis; arterolane, piperaquine, artesunate, artemether, lumefantrine and mefloquine for schistosomiasis; ivermectin, tribendimidine, pyrantel, oxantel and nitazoxanide for soil-transmitted helminths including strongyloidiasis; chloroquine, ivermectin, balapiravir, ribavirin, celgosivir, UV-4B, ivermectin and doxycycline for dengue; streptomycin, amoxicillin, clavulanate for Buruli ulcer; fluconazole and isavuconazonium for mycoses; clarithromycin and dapsone for cutaneous leishmaniasis; and tribendimidine, albendazole, mebendazole and nitazoxanide for foodborne trematodiasis. Additional paths to identification of new treatment options are needed. One promising path is exploitation of the worldwide experience with 'off-label' treatment of diseases with insufficient treatment options as pursued by the 'CURE ID' initiative.

[Cocaine-induced vasculitis and mimics of vasculitis]

Cocaine is a psychotropic tropane alkaloid and stimulant drug. Nasal insufflation of cocaine powder is a common route of administration. In Germany, cocaine is frequently adulterated with levamisole, an anthelminthic drug with immunomodulatory effects. Both substances are linked to various autoimmune conditions. Cocaine-induced midline destructive lesions cause a progressive destruction of osteocartilaginous structures within the upper respiratory tract and can mimic localized granulomatosis with polyangiitis. In addition, systemic vasculitis due to cocaine and levamisole has been reported. Differentiation of these conditions from primary vasculitis can be challenging because antineutrophil cytoplasmic antibodies (ANCA) are commonly detected. Early diagnosis of these conditions is crucial as clinical improvement is closely related to drug cessation.

Effectiveness of oral levamisole as an adjuvant to hepatitis B vaccination in healthcare workers non-responsive to previous vaccination: A randomized controlled trial

Background

Healthcare workers are at risk for HBV infection through percutaneous or mucosal contact with infected blood, body secretions, or blood products or via sharps injury. Hepatitis B vaccination, despite immunogenicity, may not induce a proper immune response in 5-10% of the general adult population. Increased immune response in healthcare providers that do not respond properly to conventional hepatitis B vaccination is an important health challenge. Therefore, the aim of the present study was to evaluate the effectiveness of hepatitis B vaccination plus oral levamisole as adjuvant in healthcare providers non-responsive to routine vaccination.

Materials and methods

The healthcare workers that were non-responsive to previous hepatitis B vaccination were enrolled in a double-blind randomized placebo-controlled clinical trial. The participants were then randomized to two groups including hepatitis B vaccination (as a three-dose series on a 0, 1, and 2-month schedule in the deltoid muscle) plus levamisole (levamisole group) and hepatitis B vaccination plus placebo (placebo group) at a 1:1 ratio. The outcome measure was the HBs antibody titer one month after receiving each dose as well as the seroprotection ratio. The side effects were also evaluated in all participants.

Results

In total, 22 subjects finished the trial (11 individual in per group). The median antibody titer one month after receiving the first and third doses increased more in the levamisole group compared to the placebo group but the difference was not significant (p ​= ​0.34, p ​= ​0.66, respectively).The seroprotection ratio after three doses was similarly high in both groups (90.9% in per group). Furthermore, the seroprotection ratio and median antibody titer had no significant correlation with age, sex, BMI, and history of smoking in intervention and control groups (p>0.05). No serious side effects were noted in both groups.

Conclusions

Re-vaccination can boost the immune response in healthcare professionals that were non-responsive to previous vaccination although the mean antibody titer was higher in the levamisole group.

Chronic levamisole exposure in male rats alters sexual behavior and induces apoptosis in the testis

Levamisole is an anti-helminthic drug developed and introduced in veterinary medicine, and it has been used more frequently after the inclusion of its usage in human medicine regarding disorders with immunomodulatory properties. In recent years, it has started to attract attention since it has beneficial effects on the treatment of COVID-19 due to its immunomodulatory properties. To investigate the effects of levamisole on sexual behavior and the reproductive system in male rats, two groups were formed the vehicle (n = 10) and levamisole (n = 10) groups. The vehicle group was given purified water whereas the levamisole group was administered with levamisole (2 mg/kg) by oral gavage daily for 4 weeks. Levamisole treatment significantly increased the mount latency (ML, P < 0.001) as well as the intromission latency (IL, P < 0.01). It also significantly prolonged postejaculatory interval (PEI, P < 0.01), decreased copulatory rate (CR, P < 0.05), and sexual activity index (SAI, P < 0.05). It significantly decreased serum monoamine oxidase A (MAO-A) levels (P < 0.05). Additionally, levamisole induced disorganizations of germinal epithelial cells of seminiferous tubules, congestion, edema in the interstitial area, and metaphase arrest in some spermatocytes (P < 0.001), and it significantly increased the immunohistochemical expressions of apoptotic Bax and cytochrome c, which is crucial proapoptotic protein, in the testis (P < 0.001). Also, levamisole significantly upregulated the mRNA levels of the apoptosis-related key regulatory genes, including Bax (Bcl-2-associated X protein, P = 0.05) and Bax/Bcl-2 ratio (P < 0.01) in testis. The current research is the first to show that levamisole may decrease sexual performance, potency, sexual motivation, and libido and induce apoptosis in the testis.

Functional validation of the truncated UNC-63 acetylcholine receptor subunit in levamisole resistance

Levamisole is a broad-spectrum anthelmintic which permanently activates cholinergic receptors from nematodes, inducing a spastic paralysis of the worms. Whereas this molecule is widely used to control parasitic nematodes impacting livestock, its efficacy is compromised by the emergence of drug-resistant parasites. In that respect, there is an urgent need to identify and validate molecular markers associated with resistance. Previous transcriptomic analyses revealed truncated cholinergic receptor subunits as potential levamisole resistance markers in the trichostrongylid nematodes Haemonchus contortus, Telodorsagia circumcincta and Trichostrongylus colubriformis. In the present study we used the Xenopus oocyte, as well as the free-living model nematode Caenorhabditis elegans, as heterologous expression systems to functionally investigate truncated isoforms of the levamisole-sensitive acetylcholine receptor (L-AChR) UNC-63 subunit. In the Xenopus oocyte, we report that truncated UNC-63 from C. elegans has a strong dominant negative effect on the expression of the recombinant C. elegans L-AChRs. In addition, we show that when expressed in C. elegans muscle cells, truncated UNC-63 induces a drastic reduction in levamisole susceptibility in transgenic worms, thus providing the first known functional validation for this molecular marker in vivo.

Novel insights on the therapeutic effect of levamisole on the chronic toxoplasmosis in mice model

Latent toxoplasmosis mostly reactivates which could result in acute encephalitis. Chronic toxoplasmosis treatments are severely constrained by Toxoplasma cyst resistance. Novel therapeutic approaches are therefore becoming more essential. In this study, the effects of levamisole (LEVA) and spiramycin on the early and late stages of experimental toxoplasmosis are investigated.

MATERIALS AND METHODS

Seventy-five Me49 Toxoplasma gondii infected Swiss albino mice were divided into five groups; (GI): noninfected control group; (GII): infected untreated control group; (GIII): infected- LEVA treated group; (GIV): infected and received combination of spiramycin and LEVA and (GV): infected-spiramycin treated group. The impact was assessed through brain cyst count by Quantitative Real-Time Polymerase Chain Reaction (PCR), interferon gamma (IFN-γ) assay, histopathological study, and total blood counts.

RESULTS

The progression of chronic toxoplasmosis could only be partially controlled by using either levamisole or spiramycin as a separate drug. The combined spiramycin and levamisole treatment significantly decreased the burden of Toxoplasma brain cyst, increased IFN-γ level, total blood parameters and improved the histopathological features especially at the late stage of infection.

IN CONCLUSION

Levamisole effectively modulated Toxoplasma-induced immune responses, resulting in chronic toxoplasmosis remission. Further clinical trials will be needed to study the effect of these combination in HIV/AIDS (human immunodeficiency virus) patients with toxoplasmosis.

Molecular Screening of Bioactive Compounds of Garlic for Therapeutic Effects against COVID-19

An outbreak of pneumonia occurred on December 2019 in Wuhan, China, which caused a serious public health emergency by spreading around the globe. Globally, natural products are being focused on more than synthetic ones. So, keeping that in view, the current study was conducted to discover potential antiviral compounds from Allium sativum. Twenty-five phytocompounds of this plant were selected from the literature and databases including 3-(Allylsulphinyl)-L-alanine, Allicin, Diallyl sulfide, Diallyl disulfide, Diallyl trisulfide, Glutathione, L-Cysteine, S-allyl-mercapto-glutathione, Quercetin, Myricetin, Thiocysteine, Gamma-glutamyl-Lcysteine, Gamma-glutamylallyl-cysteine, Fructan, Lauricacid, Linoleicacid, Allixin, Ajoene, Diazinon Kaempferol, Levamisole, Caffeicacid, Ethyl linoleate, Scutellarein, and S-allylcysteine methyl-ester. Virtual screening of these selected ligands was carried out against drug target 3CL protease by CB-dock. Pharmacokinetic and pharmacodynamic properties defined the final destiny of compounds as drug or non-drug molecules. The best five compounds screened were Allicin, Diallyl Sulfide, Diallyl Disulfide, Diallyl Trisulfide, Ajoene, and Levamisole, which showed themselves as hit compounds. Further refining by screening filters represented Levamisole as a lead compound. All the interaction visualization analysis studies were performed using the PyMol molecular visualization tool and LigPlot+. Conclusively, Levamisole was screened as a likely antiviral compound which might be a drug candidate to treat SARS-CoV-2 in the future. Nevertheless, further research needs to be carried out to study their potential medicinal use.

Cutaneous and Mucosal Conditions Associated With Cocaine Use

Cocaine and some of its main adulterants, such as levamisole, can cause multiple cutaneous and mucosal manifestations, including ischemic complications, neutrophilic dermatoses, midline destructive lesions, and vasculitis associated with antineutrophil cytoplasmic antibodies (ANCAs). Striking systemic symptoms are generally not seen. In all these conditions, positive test results may be observed for antinuclear antibodies, antiphospholipid antibodies, and various ANCAs, sometimes with characteristic staining patterns. Histology typically shows vascular changes, such as leukocytoclastic vasculitis, necrotizing vasculitis, and thrombi. We review the clinical, serologic, and histologic features of cutaneous and mucosal conditions associated with the use of cocaine and also look at pathophysiologic mechanisms, differential diagnoses, and treatments.

[Translated article] Cutaneous and Mucosal Conditions Associated With Cocaine Use

Cocaine and some of its main adulterants, such as levamisole, can cause multiple cutaneous and mucosal manifestations, including ischemic complications, neutrophilic dermatoses, midline destructive lesions, and vasculitis associated with antineutrophil cytoplasmic antibodies (ANCAs). Striking systemic symptoms are generally not seen. In all these conditions, positive test results may be observed for antinuclear antibodies, antiphospholipid antibodies, and various ANCAs, sometimes with characteristic staining patterns. Histology typically shows vascular changes, such as leukocytoclastic vasculitis, necrotizing vasculitis, and thrombi. We review the clinical, serologic, and histologic features of cutaneous and mucosal conditions associated with the use of cocaine and also look at pathophysiologic mechanisms, differential diagnoses, and treatments.

Anthelmintic resistance in sheep in the semiarid region of Minas Gerais, Brazil

Anthelmintic efficacy was evaluated among sheep that had become naturally infected with gastrointestinal nematodes in 17 flocks located in the semiarid region of Minas Gerais, Brazil. Feces were collected individually from 1021 hairy sheep to determine the number of eggs per gram of feces (EPG) and for coprocultures to identify nematode genera the nematodes. Only the animals that presented EPG counts greater than or equal to 200 were included in the study (totaling 381 sheep). The animals were divided into three treatment groups: albendazole, ivermectin and levamisole. Fourteen days after the administration of anthelmintics, fecal samples were taken from all animals. In each flock, the pre-treatment and post-treatment arithmetic mean EPG were used to calculate the efficacy (FECR) for each of the treatment groups and the lower 95% confidence limit. Data were analyzed with the "eggCounts 2.3" package in RStudio, using a Bayesian model for paired design. The anthelmintics were classified as being efficacious (when the FECR was both equal to or above 95% and the lower 95% confidence limit was equal to or above 90%) or as encountering anthelmintic resistance (when the FECR was below 95% and the lower 95% confidence limit was below 90%) or inconclusive (when none of the other criteria were fulfilled). Albendazole and ivermectin were not effective in any of the flocks. Levamisole was effective against gastrointestinal nematodes in 25% of the flocks studied. Haemonchus, Trichostrongylus and Oesophagostomum genera were identified in this study in a semiarid region of Minas Gerais, Brazil. The genus Haemonchus was the most prevalent, followed by Trichostrongylus and Oesophagostomum. After anthelmintic treatment, the most prevalent genus was Haemonchus, followed by Trichostrongylus; the genus Oesophagostomum was not detected. The highest percentage of Haemonchus larvae was observed after treatment with ivermectin, followed by albendazole and levamisole. This study revealed the existence of gastrointestinal nematodes in sheep that present multiple resistance to all three main classes of anthelmintic drugs.

Levamisole-associated multifocal inflammatory encephalopathy: clinical and MRI characteristics, and diagnostic algorithm

Levamisole-associated multifocal inflammatory encephalopathy (LAMIE) is a devastating adverse effect of levamisole (LEV) treatment. In Russia, people often use LEV without a doctor's prescription for anthelmintic prophylaxis. LAMIE often misdiagnosed as the first episode of MS or acute disseminated encephalomyelitis (ADEM). The aim of our study was to describe clinical, laboratory and morphological characteristics of LAMIE, magnetic resonance imaging (MRI) patterns and create an algorithm for the differential diagnosis. This study was a prospective observational study with retrospective analysis of cases. It was performed at two hospitals with ambulatory service for MS. We included 43 patients with LAMIE with follow-up was from 1 year to 5 years. Age was 19-68 y.o. with female predominance. The most typical manifestations of LAMIE were cerebellar, pyramidal and cognitive symptoms, and majority of patients had biphasic course of the disease. Three main types of MRI patterns were described: ADEM-like, MS-like, atypical demyelination. About 40% of patients had CSF specific oligoclonal bands synthesis, but only 20 % of them converted to MS during the period from 1 month until 2 years. The CSF albumin levels and immunoglobulin G index were elevated in LAMIE patients compared to reference values. We described results of brain biopsy in two cases. Therefore LAMIE should be considered in patients with demyelinating or inflammatory conditions with biphasic onset of the disease and variable MRI presentation.

Levamisole-induced and COVID-19-induced retiform purpura: two overlapping, emerging clinical syndromes

Levamisole exposure in cocaine users is a well-recognized cause of retiform purpura, a distinctive net-like maculopapular patch. Prolonged exposure to levamisole can lead to a serious systemic syndrome known as levamisole-induced vasculitis, most commonly involving the kidneys and lungs. More recently, retiform purpura has been observed in patients with the novel coronavirus disease of 2019 (COVID-19). Due to their overlapping dermatologic and systemic manifestations, levamisole-induced and COVID-19-induced retiform purpura may mimic one another in clinical presentation. The possibility that patients may present with one or both syndromes creates a diagnostic challenge. This review of levamisole-induced and COVID-19-induced retiform purpura highlights their corresponding and distinctive features. Additionally, we propose a unique staging system for levamisole-induced retiform purpura that may be valid for future classification of COVID-19-induced retiform purpura.

Allele specific PCR for a major marker of levamisole resistance in Haemonchus contortus

Haemonchus contortus is a haematophagous parasitic nematode that infects small ruminants and causes significant animal health concerns and economic losses within the livestock industry on a global scale. Treatment primarily depends on broad-spectrum anthelmintics, however, resistance is established or rapidly emerging against all major drug classes. Levamisole (LEV) remains an important treatment option for parasite control, as resistance to LEV is less prevalent than to members of other major classes of anthelmintics. LEV is an acetylcholine receptor (AChR) agonist that, when bound, results in paralysis of the worm. Numerous studies implicated the AChR sub-unit, ACR-8, in LEV sensitivity and in particular, the presence of a truncated acr-8 transcript or a deletion in the acr-8 locus in some resistant isolates. Recently, a single non-synonymous SNP in acr-8 conferring a serine-to-threonine substitution (S168T) was identified that was strongly associated with LEV resistance. Here, we investigate the role of genetic variation at the acr-8 locus in a controlled genetic cross between the LEV susceptible MHco3(ISE) and LEV resistant MHco18(UGA2004) isolates of H. contortus. Using single worm PCR assays, we found that the presence of S168T was strongly associated with LEV resistance in the parental isolates and F3 progeny of the genetic cross surviving LEV treatment. We developed and optimised an allele-specific PCR assay for the detection of S168T and validated the assay using laboratory isolates and field samples that were phenotyped for LEV resistance. In the LEV-resistant field population, a high proportion (>75%) of L₃ encoded the S168T variant, whereas the variant was absent in the susceptible isolates studied. These data further support the potential role of acr-8 S168T in LEV resistance, with the allele-specific PCR providing an important step towards establishing a sensitive molecular diagnostic test for LEV resistance.

"Clinical Efficacy of Mycophenolate Mofetil versus Levamisole Therapy in Frequently Relapsing and Steroid Dependent Childhood Nephrotic Syndrome" - A retrospective comparative analysis

BACKGROUND

Children with Frequently relapsing (FR) or Steroid dependent (SD) Nephrotic Syndrome (NS) often develop side effects of corticosteroids. Various steroid-sparing agents are in practice, but only a few studies exist so far which have compared the safety and efficacy of these two commonly used agents.

METHODS

We did a retrospective medical records review of children with FRNS or SDNS who had Levamisole or MMF as a steroid-sparing agent with a minimum follow-up period of 12 months. The aim was to compare the course of our patients on MMF and Levamisole. Our primary objective was to determine the number of children in sustained remission and those with the infrequently relapsing course on Levamisole and MMF and, the median time to relapse in months in the two groups. The secondary objective was to compare time to first relapse and number of relapses in FRNS and SDNS group children on MMF and Levamisole.

RESULTS

A total of 88 children (34% female) with diagnosis FR/SDNS (44 each) were included in the study. Thirty-nine patients took Levamisole, while forty-nine received MMF therapy. The median age of presentation at the relapsing course was 4.2 years. The proportion of children with sustained remission or infrequent relapsing (IFR) course on MMF was 73.6%, compared to 48.71% on Levamisole (p-value 0.015). Also, the median time to first relapse was 12 months (24, 1.5) and 4.5 months (24, 1) on respective medications.

CONCLUSIONS

Clinical outcome was superior in the MMF group than Levamisole, especially in SDNS patients, and also MMF was more efficacious in maintaining sustained remission. This article is protected by copyright. All rights reserved.

Worm control practices on free-range egg farms in Australia and anthelmintic efficacy against nematodes in naturally infected layer chickens

This study investigated worm control practices by free-range egg farmers and the efficacy of the commercial anthelmintics levamisole (LEV), piperazine (PIP), flubendazole (FLBZ) and fenbendazole (FBZ) against gastrointestinal nematodes on two free-range layer farms in Australia. An online survey comprising 36 questions was designed and implemented using SurveyMonkey. The survey contained questions about participant demographics, farm and flock characteristics, perceived intestinal worm importance, infection monitoring, deworming and other worm control practices. A link for the survey was emailed to free range egg producers from their industry body in December 2019. The anthelmintic efficacy trial was conducted in a total of 229 layers naturally infected with Ascaridia galli, Hetarakis gallinarum, Capillaria spp. and/or tape worms. Chickens received a single oral dose of LEV (28 mg/kg), PIP (100 mg/kg), FBZ (10 mg/kg) or LEV-PIP co-administered at their full individual doses, and FLBZ (Flubenol®), 30 ppm or 60 ppm) in the feed over 7 days. Anthelmintic efficacies were estimated by both worm count reduction (WCR %) and excreta egg count reduction (EECR %) tests 10 days after start of treatment. The survey with a response rate of 16/203, revealed that worm infection was of moderate concern to the producers and the majority (68%) felt that the current anthelmintics work effectively. The level of understanding of worms, monitoring and control practices did not reveal any major deficiencies of concern. The most commonly used anthelmintic was LEV (73%) followed by PIP (45%). Based on a standard cut-off value (≥90%), LEV, LEV-PIP, and FBZ attained the desired efficacy but PIP exhibited reduced efficacy against immature A. galli (61-85%), all stages of H. gallinarum (42-77%) and Capillaria spp. (25-44%). FLBZ was highly effective against all stages of roundworms and tapeworm infections. Even though there was some association between the efficacies estimated by WCR % and EECR % the latter was poorly associated in the natural infection model and hence does not provide a reasonable alternative for assessing anthelmintic efficacy when immature stages of the lifecycle are included. These results show no evidence of loss of susceptibility to the tested anthelmintics on these farms supporting the perception of producers that participated in the survey that current treatments work effectively. The reduced efficacy of PIP against some species and immature stages is related to its spectrum of activity rather than providing evidence of emerging resistance.

Molecular docking, molecular dynamics simulation, and ADMET analysis of levamisole derivatives against the SARS-CoV-2 main protease (MPro)

Introduction: The new species of coronaviruses (CoVs), SARS-CoV-2, was reported as responsible for an outbreak of respiratory disease. Scientists and researchers are endeavoring to develop new approaches for the effective treatment against of the COVID-19 disease. There are no finally targeted antiviral agents able to inhibit the SARS-CoV-2 at present. Therefore, it is of interest to investigate the potential uses of levamisole derivatives, which are reported to be antiviral agents targeting the influenza virus.

Methods: In the present study, 12 selected levamisole derivatives containing imidazo[2,1-b]thiazole were subjected to molecular docking in order to explore the binding mechanisms between these derivatives and the SARS-CoV-2 M^pro (PDB: 7BQY). The levamisole derivatives were evaluated for in silico ADMET properties for wet-lab applicability. Further, the stability of the best-docked complex was checked using molecular dynamics (MD) simulation at 20 ns.

Results: Levamisole derivatives and especially molecule N°6 showed more promising docking results, presenting favorable binding interactions as well as better docking energy compared to chloroquine and mefloquine. The results of ADMET prediction and MD simulation support the potential of the molecule N°6 to be further developed as a novel inhibitor able to stop the newly emerged SARS-CoV-2.

Conclusion: This research provided an effective first line in the rapid discovery of drug leads against the novel CoV (SARS-CoV-2).

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.

Therapeutic efficacy of triclabendazole in comparison to combination of triclabendazole and levamisole in sheep naturally infected with Fasciola sp

Fascioliasis is an important parasitic disease which affects productivity of ruminants, and imposes significant economic losses. Benzimidazoles are effective in the treatment of fascioliasis; however, there are several reports on benzimidazoles resistant flukes. Combinational therapy is an approach to delay the emergence of resistant flukes. The present study aimed to compare the efficacy of triclabendazole (TBZ) and combination of triclabendazole and levamisole (TBZ + LVM) in the treatment of sheep naturally infected with Fasciola sp. For this purpose, 40 ewes infected with Fasciola sp. in three groups received TBZ, and TBZ + LVM, or remained untreated as CON. Fecal egg count (FEC), fecal egg count reduction (FECR), liver enzymes activity, albumin, globulin, and total protein levels were measured on day 0, 7, 14, and 28 post treatments. Obtained results showed that treatment with TBZ and TBZ + LVM resulted in significant reduction in FEC (P < 0.05), and FECR reached to values of higher than 90% on 28 day post treatment. The FEC for TBZ + LMV on day 7 and 14 were 12.25 ± 3.82 and 3.08 ± 1.03, respectively which was significantly lower in comparison to TBZ and CON (P < 0.05). Efficacy of TBZ + LMV was higher than TBZ on day 7 and 14 post treatment; however, no significant difference was observed on 28 day. The liver enzyme activities on days 7 and 14 were lower in the TBZ + LVM sheep in comparison to the TBZ and CON. Treatment with TBZ or TBZ + LVM resulted in an increase in albumin and a decrease in globulin. Over all, the present study clarified the importance of combinational therapy, and demonstrated that combination of TBZ + LVM resulted in higher efficacy and earlier improvement of liver conditions in sheep naturally infected with Fasciola sp.

Levamisole causes a transient increase in plasma creatinine levels but does not affect kidney function based on cystatin C

BACKGROUND

In pediatric patients treated with levamisole to prevent relapses of idiopathic nephrotic syndrome (INS), a transient and non-progressive rise in creatinine levels has been observed. It has been suggested that levamisole affects tubular secretion of creatinine. However, other potential mechanisms - nephrotoxicity and interference with the analytical assay for creatinine - have never been thoroughly investigated.

METHODS

In three steroid-sensitive nephrotic syndrome (SSNS) patients with elevated plasma creatinine levels, treated with levamisole 2.5 mg/kg every other day, serum cystatin C was determined. The glomerular filtration rate (GFR) was estimated using the full age spectrum for creatinine and the full age spectrum for cystatin C equations. Interference of levamisole with the enzymatic creatinine assay was tested using spare human plasma of different creatinine concentrations spiked with levamisole (4, 20, and 100 µM).

RESULTS

Three patients who received levamisole with elevated plasma creatinine levels had normal serum cystatin C levels and corresponding estimated GFR. There was no assay interference.

CONCLUSION

Levamisole increases plasma creatinine levels, which is most probably due to impaired tubular secretion of creatinine since there was no assay interference and patients had normal eGFR based on serum cystatin C. However, interference of metabolites of levamisole could not be excluded. To monitor GFR, cystatin C in addition to creatinine should be used and be measured before and during levamisole use.

Anthelmintic efficacy evaluation against different developmental stages of Ascaridia galli following individual or group administration in artificially trickle-infected chickens

The efficacy of commercially available anthelmintics against mature and immature stages (including ovicidal effects) of two Australian field isolates of Ascaridia galli was evaluated in two separate experiments. The anthelmintics tested were levamisole (LEV), piperazine (PIP) and flubendazole (FBZ) plus LEV-PIP. A total of 192 artificially trickle-infected young cockerels (96 birds per isolate) were randomized into sixteen experimental groups of 12 cockerels each (7 treatments and 1 untreated control per isolate). Chickens received label-recommended doses of LEV (28 mg/kg), PIP (100 mg/kg) or LEV-PIP co-administered at their full individual doses as a single oral dose or in group drinking water at recommended concentrations of 0.8 mg/ml or 2.5 mg/ml over eight hours for 1 and 2 days respectively and FLBZ (30 ppm) in the feed over 7 days. Anthelmintic efficacies were assessed by worm count reduction (WCR%) and excreta egg count reduction (EECR%) estimated by two methods. Ten days post treatment, all untreated control birds harboured mixed worm population of 10.1 and 12.3/bird for each isolate respectively which was significantly higher (P < 0.0001) than counts in all treatment groups. Luminal or histotrophic larvae comprised 50-57 % of the total worm count. For LEV, PIP and LEV-PIP, individual oral administration provided a somewhat higher efficacy than group medication in drinking water. EECR% values were inconsistent with WCR% and found to be only an indicator of efficacy against adult worms. All developmental stages of the two A. galli isolates were highly susceptible to FLBZ (100 %) followed by LEV-PIP (92.4-100 %) and LEV (87.7-100 %). PIP exhibited good efficacy against adult worms (92-97 %) but reduced efficacy against luminal (79-84 %) and histotrophic (61-72 %) larvae. Embryonation capacity of eggs recovered from worms expelled after treatment with LEV (47-54 %), PIP (44-54 %) or LEV-PIP (45-48 %) did not differ from those from untreated birds (50-51 %) whereas eggs from FLBZ treated worms had a significantly lower (P < 0.05) capacity to embryonate (≤ 2 %). Put together, our results demonstrate no evidence of resistance of the test A. galli isolates to the tested anthelmintics but a significant advantage of FLBZ, followed by LEV-PIP and LEV over PIP in the control of A. galli, specifically with regard to immature stages. A. galli worms expelled after treatment with LEV, PIP or their combination, but not FLBZ contain viable eggs. This has epidemiological implications and may also provide an option for isolating eggs from mature worms for A. galli propagation experiments without having to sacrifice birds.

DMSO Delays Alzheimer Disease Causing Aβ-induced Paralysis in C. elegans Through Modulation of Glutamate/Acetylcholine Neurotransmission

Background:

Alzheimer’s disease (AD), a prevalent neurodegenerative disease with progressive dementia and neurotransmission (NT)-dysfunction-related complications in older adults, is known to be caused by abnormal Amyloid-β (Aβ) peptide and associated amyloid plaques in the brain. Drugs to cure AD are not in sight. Two major excitatory neurotransmitters, glutamate (Glu) and acetylcholine (ACh), and their signaling systems are implicated in AD.

Objective:

To determine the effect of various NT-altering compounds including fenobam, quisqualic acid, and dimethyl sulfoxide (DMSO) in the protection against Aβ toxicity. Further, to identify the potential mechanism through which the protection happens.

Methods:

The well-known C. elegans AD model, CL4176, in which human Aβ expression is turned on upon a temperature shift to 25 °C that leads to paralysis, was screened for protection/delay in paralysis because of Αβ toxicity. While screening the compounds, dimethyl sulfoxide (DMSO), a universal solvent used to solubilize compounds, was identified to provide protection. Aldicarb and levamisole assays were performed to identify the contribution of ACh neurotransmission in Αβ toxicity protection by DMSO.

Results:

One percent and two percent DMSO delayed paralysis by 48% and 90%, respectively. DMSO was dominant over one of the Glu-NT pathway-related compounds, Fenobam-Group I mGluR antagonist. But DMSO provided only 30% to 50% protection against Quisqualic acid, the Glu-agonist. DMSO (2%) delayed ACh-NT, both presynaptic acetylcholine esterase inhibitor (AchEi)-aldicarb and postsynaptic-iAChR-agonst-levamisole induced paralysis, by ∼70% in CL4176. DMSO seems to be altering Ca²⁺ ion permeability essential for NT as EthyleneDiamine Tetra-Acetic acid (EDTA) and DMSO provided similar aldicarb resistance either combined or alone in wildtype worms. But postsynaptic Ca²⁺ depletion by EDTA could reverse DMSO-induced levamisole hypersensitivity. Surprisingly, the absence of FOrkhead boXO (FOXO) transcription factor homolog, daf-16 (loss-of-function mutant), a critical transcription factor in the reduced IIS-mediated longevity in C. elegans, abolished DMSO-mediated Ald^R.

Conclusion:

DMSO and Fenobam protect against Aβ toxicity through modulation of NT.

Qualitative LC/Q-TOF Analysis of Umbilical Cord Tissue via Data-Dependent Acquisition as an Indicator of In Utero Exposure to Toxic Adulterating Substances

Toxic adulterants are drug or chemical agents used to add bulk volume to traditional drugs of abuse such as cocaine, and heroin. These cutting agents include levamisole, metamizole, noxiptillin, phenacetin, and xylazine as well as common legal drugs such as acetaminophen, caffeine, diphenhydramine, lidocaine, quinine, quetiapine, and tramadol. Because they possess pharmacological activity they result in exposure of the user, but also in the case of pregnant women, the developing fetus, to potential drug toxicity. We describe the development, validation, and implementation of a rapid (48 second sample-to-sample) test based on a qualitative data-dependent liquid chromatography-quadrupole time of flight mass spectrometry (LC/Q-TOF) method for the analysis of toxic adulterating substances in umbilical cord tissue (UCT) samples. The method provides a means of studying potential in utero exposure to these agents. Library spectra comparison at 3 different collision energies was used in conjunction with retention time and accurate mass to identify these substances in UCT. Analytically based reporting limits were established to determine positivity rates of adulterants in UCT utilizing a standard addition approach. The method was applied to authentic cocaine and opioid positive UCT's to screen for toxic adulterants. There were a total of 82 potential adulterant positives found in a 30-sample cohort of authentic UCT samples, with an average of 2.7 substances per case. Lidocaine was the predominant finding followed by caffeine, and diphenhydramine all of which could result from non-illicit drug exposure, however, there were positives for levamisole, phenacetin, noxiptillin, and xylazine none of which are approved in the United States for human therapeutic use. This initial set of data established a preliminary positivity rate of potentially toxic adulterants in UCT samples positive for cocaine or opioid use.

The effects of levamisole and albendazole on spermatological parameters, testosterone levels, and sperm DNA damage in Saanen bucks

This study aimed to investigate the effect of levamisole and albendazole on spermatological parameters, testosterone levels, and sperm DNA damage in Saanen bucks. For this purpose, twenty-four Saanen bucks were divided into three groups as control, levamisole, and albendazole administration group. The control group received only water (20 ml, oral), the levamisole group received 7.5 mg/kg of levamisole (2 oral tablets once daily for 2 days) + water (20 ml, oral), and the albendazole group received 7.5 mg/kg of albendazole (1 oral tablet) + water (20 ml, oral). Semen and blood samples were collected from all animals, both before drug application (day 0) and within a 2-day interval after drug application between day 1 (day of the treatment) and day 11. Spermatological parameters were evaluated immediately after collection. Testosterone levels were also measured from the blood samples with ELISA. Sperm DNA damage was determined with comet assay. The present research showed that especially albendazole administration decreased spermatological parameters and levamisole administration decreased testosterone levels. Significant sperm DNA damage was seen after both albendazole and levamisole administration. As a result, albendazole and levamisole administration should be used carefully on Saanen bucks, especially during the breeding season.

Vitamin B6 deficiency with normal plasma levels of pyridoxal 5'-phosphate in perinatal hypophosphatasia

Pyridoxal 5'-phosphate (PLP), the principal circulating form of vitamin B6 (B6), is elevated in the plasma of individuals with hypophosphatasia (HPP). HPP is the inborn-error-of-metabolism caused by loss-of-function mutation(s) of ALPL, the gene that encodes the "tissue-nonspecific" isoenzyme of alkaline phosphatase (TNSALP). PLP accumulates extracellularly in HPP because it is a natural substrate of this cell-surface phosphomonoester phosphohydrolase. Even individuals mildly affected by HPP manifest this biochemical hallmark, which is used for diagnosis. Herein, an exclusively breast-fed newborn boy with life-threatening perinatal HPP had uniquely normal instead of markedly elevated plasma PLP levels before beginning asfotase alfa (AA) TNSALP-replacement therapy. These abnormal PLP levels were explained by B6 deficiency, confirmed by his low plasma level of 4-pyridoxic acid (PA), the B6 degradation product. His mother, a presumed carrier of one of his two ALPL missense mutations, had serum ALP activity of 50 U/L (Nl 40-130) while her plasma PLP level was 9 μg/L (Nl 5-50) and PA was 3 μg/L (Nl 3-30). Her dietary history and breast milk pyridoxal (PL) level indicated she too was B6 deficient. With B6 supplementation using a breast milk fortifier, the patient's plasma PA level corrected, while his PLP level remained in the normal range but now in keeping with AA treatment. Our experience reveals that elevated levels of PLP in the circulation in HPP require some degree of B6 sufficiency, and that anticipated increases in HPP can be negated by hypovitaminosis B6.

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.

Adverse reactions with levamisole vary according to its indications and misuse: a systematic pharmacovigilance study

AIM

Levamisole was initially prescribed for the treatment of intestinal worms. Because of immunomodulatory properties, levamisole has been used in inflammatory pathologies and in cancers in association with 5-fluorouracil. Levamisole is misused as a cocaine adulterant. Post-marketing reports have implicated levamisole in the occurrence of adverse drug reactions (ADRs) and its use is now limited in Europe and North America. In contrast, all other parts of the World continue to use single-dose as an anthelmintic. The aim of this study was to identify ADRs reported after levamisole exposure in VigiBase, the WHO's pharmacovigilance database, and analyze their frequency compared to other drugs and according to levamisole type of use.

METHODS

All levamisole-related ADRs were extracted from VigiBase®. Disproportionality analyses were conducted to investigate psychiatric, hepatobiliary, renal, vascular, nervous, blood, skin, cardiac, musculoskeletal and general ADRs associated with levamisole and other drugs exposure. In secondary analyses, we compared the frequency of ADRs between levamisole and mebendazole and between levamisole type of use.

RESULTS

Among the 1763 levamisole-related ADRs identified, psychiatric disorders (Reporting Odds-Ratio with 95% confidence intervals: 1.4 [1.2-2.6]), hepatobiliary disorders (2.4 [1.9-4.3]), vasculitis (6.5 [4.1-10.6]), encephalopathy (22.5 [17.4-39.9]), neuropathy (4.3 [2.9-7.1]), hematological disorders, mild rashes and musculoskeletal disorders were more frequently reported with levamisole than with other drug. The majority of levamisole-related ADRs occurred when the drug was administrated for a non-anti-infectious indication.

CONCLUSION

The great majority of the levamisole-related ADRs concerned its immunomodulatory indication and multiple doses regimen. Our results suggest that single-dose treatments for anthelmintic action have a good safety profile.

Comparison of electrophysiological and motility assays to study anthelmintic effects in Caenorhabditis elegans

Currently, only a few chemical drug classes are available to control the global burden of nematode infections in humans and animals. Most of these drugs exert their anthelmintic activity by interacting with proteins such as ion channels, and the nematode neuromuscular system remains a promising target for novel intervention strategies. Many commonly-used phenotypic readouts such as motility provide only indirect insight into neuromuscular function and the site(s) of action of chemical compounds. Electrophysiological recordings provide more specific information but are typically technically challenging and lack high throughput for drug discovery. Because drug discovery relies strongly on the evaluation and ranking of drug candidates, including closely related chemical derivatives, precise assays and assay combinations are needed for capturing and distinguishing subtle drug effects.

Past studies show that nematode motility and pharyngeal pumping (feeding) are inhibited by most anthelmintic drugs. Here we compare two microfluidic devices (“chips”) that record electrophysiological signals from the nematode pharynx (electropharyngeograms; EPGs) ─ the ScreenChip™ and the 8-channel EPG platform ─ to evaluate their respective utility for anthelmintic research. We additionally compared EPG data with whole-worm motility measurements obtained with the wMicroTracker instrument. As references, we used three macrocyclic lactones (ivermectin, moxidectin, and milbemycin oxime), and levamisole, which act on different ion channels. Drug potencies (IC₅₀ and IC₉₅ values) from concentration-response curves, and the time-course of drug effects, were compared across platforms and across drugs. Drug effects on pump timing and EPG waveforms were also investigated. These experiments confirmed drug-class specific effects of the tested anthelmintics and illustrated the relative strengths and limitations of the different assays for anthelmintic research.

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Anthelmintic drugs inhibit pharyngeal pumping and motility in C. elegans.

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Two electrophysiological assays and one motility assay were compared.

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Macrocyclic lactones and levamisole have drug-class-specific effects.

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A combination of assays most fully reveals anthelmintic effects.

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Strengths and limitations of the three assays were identified.

Pharmacokinetics and pharmacodynamics of single and multiple-dose levamisole in belugas (Huso huso): Main focus on immunity responses

The pharmacokinetics of levamisole were determined in the belugas after single intravascular (IV), and single and multiple-dose oral by feed administrations. Also, the effect of levamisole (LVM) on the stress and immune responses of belugas were assessed. One hundred-fourteen healthy belugas in 4 different groups received single LVM administration at the doses of 50 and 100 mg/kg via IV and oral routes. A separate group of 24 belugas were administered oral LVM at the dose of 100 mg/kg for 5 days. Blood samples were collected at different time points after administrations to measure plasma concentrations of LVM by a validated high-performance liquid chromatography (HPLC) assay. For immunological evaluations, a total of 126 belugas received 50 and 100 mg/kg LVM via medicated feed for 5 days or served as the control without any medication; blood samples were recovered on day 0, 1, 3, 5, 7, 10, and 14 to measure hemolytic activity of the complement system (HAC₅₀), serum lysozyme activity, serum antibacterial activity, glucose, cortisol, total protein, albumin and C3 contents. In the single-dose administration, quantified LVM concentrations were dose-dependent and the oral bioavailability was in the range of 43.2-49.6%. In the multiple-dose administration, the peak plasma concentration at the steady state was 45.2 mg/ml, and accumulation ratio was calculated as 3.6. In the immunological study, LVM especially at the dose of 100 mg/kg increased HAC₅₀, lysozyme and antibacterial activity in the sera of treated fish. No significant effect of LVM on glucose and albumin content was observed, but cortisol levels decreased and C₃ content was increased, more significantly by LVM at the dose of 100 mg/kg. Our results indicate that LVM is well absorbed after oral administration and reached to concentrations that can affect stress indicators and improve immune responses in belugas.

Levamisole and ANCA positivity in childhood nephrotic syndrome

BACKGROUND

This study aimed to determine the prevalence of ANCA positivity in children managed with levamisole as a steroid-sparing agent for nephrotic syndrome (NS).

METHODS

Medical records of children with steroid-sensitive NS managed with levamisole therapy at Sydney Children's Hospital between 1/1/2000 and 31/12/2018 were retrospectively reviewed. Main outcome measure was side effects of levamisole therapy including ANCA positivity.

RESULTS

Seventy-one children, median age 3 years and 1 month (IQR 29-68 months) at first presentation, were subsequently managed with levamisole. 60.6% were male and 65% Caucasian. 47.9% had frequently relapsing (FR)NS and 52.1% steroid-dependent (SD)NS. Overall, there was a median reduction in relapses from 3 (IQR 1-5) to 0.4 relapses (IQR 0-1) per year after levamisole was commenced. Levamisole was successful in preventing relapse in 19 (29%) patients and was used for median 24 (22 to 25) months. Levamisole was discontinued due to relapse in 25 patients (38%) after median 12 (5-28) months. Side effects occurred in 28 patients (42.4%); the most common side effect was ANCA positivity in 12 patients. In eleven of these patients, levamisole was discontinued; in one patient, low-level titres were documented and spontaneously resolved without cessation of levamisole. Two patients developed ANCA-associated vasculitis.

CONCLUSION

ANCA positivity is a common side effect of levamisole and was seen in 18.2% of our patients. Monitoring is required to determine side effects including ANCA positivity and treatment modified accordingly.

Design, optimization and evaluation of a microemulsion-based hydrogel with high malleability for enhanced transdermal delivery of levamisole

The objective of the present study was to prepare and evaluate a microemulsion-based hydrogel with high malleability as a transdermal delivery carrier for levamisole (LMS). A pseudo-ternary phase diagram and D-optimal mixture design were utilized to screen and optimize the microemulsion, and the formulation comprised 7.5% Maisine^TM35-1, 33% S_mix and 59.5% water. The microemulsion was physically stable with an average size of 19.3 ± 0.1 nm and zeta potential of -3.84 ± 0.05 mV. Moreover, a highly malleable alginate-boronic acid (alginate-BA) gel was prepared and could come into close contact with highly curved skin. The optimized microemulsion was loaded into alginate-BA gel and subjected to ex vivo and in vivo investigation. The microemulsion-based gel had desirable characterization, good stability and negligible skin irritation. The results of ex vivo permeation study showed that LMS achieved a significantly higher cumulative amount from the LMS-loaded microemulsion-based gel than that from the LMS-gel. The pharmacokinetic study showed a twofold increase in relative bioavailability compared to the commercial liniment. These results provide insight into the capability of the developed malleable microemulsion-based gel to enhance the transdermal permeation and bioavailability of LMS.

contortus

The nematode Haemonchus contortus is one of the most prevalent and pathogenic parasites in small ruminants. Although usually controlled using anthelmintics, the development of drug resistance by the parasite has become a major issue in livestock production. While the molecular detection of benzimidazole resistance in H. contortus is well developed, the molecular tools and protocols are far less advanced for the detection of levamisole resistance. The hco-acr-8 gene encodes a critical acetylcholine susceptible subunit that confers levamisole-sensitivity to the receptor. Here, we report the development of a droplet digital PCR assay as a molecular tool to detect a 63 bp deletion in the hco-acr-8 that has been previously associated with levamisole resistance. Sanger sequencing of single adult H. contortus yielded 56 high-quality consensus sequences surrounding the region containing the deletion. Based on the sequencing data, new primers and probes were designed and validated with a novel droplet digital PCR assay for the quantification of the deletion containing “resistant” allele in genomic DNA samples. Single adult worms from six phenotypically described isolates (n = 60) and from two Swedish sheep farms (n = 30) where levamisole was effective were tested. Even though a significant difference in genotype frequencies between the resistant and susceptible reference isolates was found (p = 0.01), the homozygous “resistant” genotype was observed to be abundantly present in both the susceptible isolates as well as in some Swedish H. contortus samples. Furthermore, field larval culture samples, collected pre- (n = 7) and post- (n = 6) levamisole treatment on seven Swedish sheep farms where levamisole was fully efficacious according to Fecal Egg Count Reduction Test results, were tested to evaluate the frequency of the “resistant” allele in each. Frequencies of the deletion ranged from 35 to 80% in the pre-treatment samples, whereas no amplifiable H. contortus genomic DNA was detected in the post-treatment samples. Together, these data reveal relatively high frequencies of the 63 bp deletion in the hco-acr-8 both on individual H. contortus and field larval culture scales, and cast doubt on the utility of the deletion in the hco-acr-8 as a molecular marker for levamisole resistance detection on sheep farms.

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Acr8b – levamisole resistance marker investigated in single worms and larval cultures.

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Individuals homozygous for acr8b found more commonly, even in susceptible isolates.

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Levamisole treatment efficacy was unaffected by increased acr8b frequencies in larvae.

Efficacy and safety of Levamisole treatment in clinical presentations of non-hospitalized patients with COVID-19: a double-blind, randomized, controlled trial

BACKGROUND

Levamisole has shown clinical benefits in the management of COVID-19 via its immunomodulatory effect. However, the exact role of Levamisole effect in clinical status of COVID-19 patients is unknown. We aimed to evaluate the efficacy of Levamisole on clinical status of patients with COVID-19 during their course of the disease.

METHODS

This prospective, double-blind, randomized controlled clinical trial was performed in adult patients with mild to moderate COVID-19 (room-air oxygen saturation > 94%) from late April 2020 to mid-August 2020. Patients were randomly assigned to receive a 3-day course of Levamisole or placebo in combination with routine standard of care.

RESULTS

With 25 patients in each arm, 50 patients with COVID-19 were enrolled in the study. Most of the study participants were men (60%). On days 3 and 14, patients in Levamisole group had significantly better cough status distribution when compared to the placebo group (P-value = 0.034 and 0.005, respectively). Moreover, there was significant differences between the two groups in dyspnea at follow-up intervals of 7 (P-value = 0.015) and 14 (P-value = 0.010) days after receiving the interventions. However, no significant difference in fever status was observed on days 1, 3, 7, and 14 in both groups (P-value > 0.05).

CONCLUSION

The results of the current study suggest that Levamisole may improve most of clinical status of patients with COVID-19. The patients receiving Levamisole had significantly better chance of clinical status including cough and dyspnea on day 14 when compared to the placebo. However, the effect-size of this finding has uncertain clinical importance.

TRIAL REGISTRATION

The trial was registered as IRCT20190810044500N7 (19/09/2020).

Series of three cases and literature review

Pyoderma gangrenosum associated to the use of cocaine/levamisole is a rare condition associated to their consumption. Cocaine use is frequent in Colombia, and the substance is contaminated with levamisole, an anthelmintic that increases the psychotropic effects and enhances its side effects. We present three clinical cases of patients with ulcerated lesions, in which the diagnosis was pyoderma gangrenosum secondary to the use of cocaine contaminated with levamisole. This called the attention of the health staff to investigate the abuse of substances in gangrenous pyoderma and also evidence that the interruption of consumption was the basis of management.

Anthelmintic efficacy of fenbendazole and levamisole in native fowl in northern Iran

BACKGROUND

With the increasing number of free-range domestic chickens, helminth parasites have potentially become more of a threat to commercial flocks in recent years, and routine poultry deworming is needed to improve the efficiency of chicken production. The present study deals with a field trial to study the efficacy of two generally used anthelmintics, fenbendazole and levamisole, against gastrointestinal nematodes of domestic chickens in northern Iran.

METHODS

Of 45 domestic chicken flocks involved in the study, 20 flocks were selected to participate in fecal egg count reduction testing based on flock size from April 2017 to September 2018. The infected chickens were randomly divided into three equal groups of 30 each. Ninety chickens in the infected groups received one of the following treatments (d 0 of treatment): Group 1: 5 mg kg^-1 body weight (BW) fenbendazole for 3 consecutive days; Group 2: 16 mg kg^-1 BW levamisole; Group 3 control: placebo, water + DMSO (dimethylsulfoxide). The efficacy of the treatments was evaluated by comparing fecal egg counts in the treated and control groups.

RESULTS

Examination of three flocks of chickens from the control group showed that 95.0% of the animals were infected with gastrointestinal nematodes with an average geometric value of 361 eggs per gram of feces. Fenbendazole at a dose of 5 mg kg^-1 BW for 3 days showed an efficacy of 83.7% (P ≥ 0.05), and levamisole at a dose of 16 mg kg^-1 BW showed 71.8% efficacy (P ≥ 0.05) with geometric mean eggs in a gram of feces of 100 and 199.6, respectively. In general, fenbendazole and levamisole treatment led to significantly lower activity. The result of this study revealed that fenbendazole was a better and more effective dewormer than levamisole on the three Iranian domestic chicken flocks, but the difference was not significant. Capillaria spp. were the most generally resistant nematodes followed by Trichostrongylus spp. and Amidostomum anseris.

CONCLUSION

Our results indicated that fenbendazole and levamisole effectively reduced the number of nemathodes in three Iranian domestic chicken flocks. Given the results of our study, resistance can be expected in the parasitic helminths of poultry. Additional larger scale studies are required to determine the prevalence of anthelmintic resistance in the poultry industry.

Combined moxidectin-levamisole treatment against multidrug-resistant gastrointestinal nematodes: A four-year efficacy monitoring in lambs

Nematicide combinations may be a valid strategy to achieve effective nematode control in the presence of drug resistance. The goal of the current trial was to evaluate the pharmaco-parasitological performance of the moxidectin (MOX) and levamisole (LEV) combination after four years of continuous use in lambs naturally parasitized with multi-resistant gastrointestinal nematodes. At the beginning of the trial, 40 lambs were divided into four groups (n = 10), which were untreated (control) or subcutaneously treated with MOX (0.2 mg/kg), LEV (8 mg/kg) or with the combination MOX + LEV (administered separately at 0.2 and 8 mg/kg, respectively). Blood samples were collected at different times post-treatment and LEV and MOX plasma concentrations were measured by HPLC. The clinical efficacy of the continuous use of MOX + LEV combination was assessed with the controlled efficacy test (CET), performed at the beginning and end of the study, and with the faecal egg count reduction (FECR) test, performed over the four-year study period. No significant adverse pharmacokinetic changes were observed either for MOX or LEV after their co-administration to infected lambs. The CET (first year) showed efficacies of 84.3 % (Haemonchus contortus), 100 % (Teladorsagia circumcincta and Trichostrongylus axei), and 97.4 % (T. colubriformis). After the repetitive use of the combined treatment for four years, those efficacies remained high (100 %) and only decreased to 58 % against T. colubriformis. The evaluation of the FECR over the study period showed fluctuations in the performance of the combined administration. The initial FECR (2014) was 99 % (MOX), 85 % (LEV) and 100 % (MOX + LEV). The co-administration of MOX + LEV during the four-year experimental period resulted in a significantly higher anthelmintic effect (87 %) than that of MOX (42 %) or LEV (69 %) given alone. The combined use of MOX + LEV to control resistant gastrointestinal nematodes appears to be a valid strategy under specific management conditions. A high initial therapeutic response to the combination would be a relevant feature for the success of this tool.