A new class of antiparasitic drugs.

Cyanotriazole compounds "poison" topoisomerase II of pathogenic trypanosomatids.

Efficacy of fipronil/(S)-methoprene/eprinomectin/praziquantel (Broadline®) against Thelazia callipaeda in naturally infected cats.

BACKGROUND: The present clinical field trial was conducted to assess the efficacy of a broad-spectrum parasiticide spot-on formulation containing eprinomectin (Broadline®) against Thelazia callipaeda eyeworm in naturally infected cats. METHODS: Fifteen privately owned cats harboring at least one live adult T. callipaeda were included in the study. Cats were randomly allocated to an untreated control group of seven cats or to a Broadline®-treated group of eight cats. Cats were treated on Day 0; ocular examinations were performed at inclusion and on Days 7 and 14; eyeworms were recovered and counted on Day 14. The primary efficacy assessment was based on group comparison of number of T. callipaeda on Day 14. RESULTS: Seven days after treatment, six of eight treated cats were negative for eyeworm infection per visual examination, and on Day 14 no eyeworms were found in the treated cats while the seven untreated cats were still infected (geometric mean: 1.97). All cats had inflammatory ocular signs at inclusion; on Day 14, five of eight treated cats had recovered while all untreated control cats were still symptomatic. All collected parasites were confirmed to be T. callipaeda by morphology and molecular characterization. CONCLUSIONS: A single treatment with Broadline® provided 100% efficacy against feline thelaziosis and improved related ocular inflammation signs.

[Purpura due to Strongyloides stercoralis in an immunocompetent patient]. / Púrpura por Strongyloides stercoralis en un paciente inmunocompetente.

Infection with Strongyloides stercoralis is a common parasitic infection in tropical and subtropical regions, including the Peruvian Amazon. The clinical manifestations are varied in patients with immunocompromised disease, and the systemic spread of the disease is frequent, compromising different organs and systems. Cutaneous manifestations are infrequent, being described in patients with some degree of immunosuppression. We present the case of an immunocompetent patient who developed a reactive purpura due to chronic Strongyloides stercoralis infection. Thus, skin involvement is possible in immunocompetent patients with systemic exacerbation due to this parasite.

Púrpura por Strongyloides stercoralis en un paciente inmunocompetente / Purpura due to Strongyloides stercoralis in an immunocompetent patient

Resumen La infección por Strongyloides stercoralis es una parasitosis frecuente en las regiones tropicales y subtropicales, incluyendo la Amazonía peruana. En pacientes con inmunocompromiso, las manifestaciones clínicas son variadas y es frecuente la diseminación sistémica de la enfermedad, con compromiso de diversos órganos. Las manifestaciones cutáneas son infrecuentes y se describen en pacientes con algún grado de inmunosupresión. Se presenta el caso de un paciente inmunocompetente que desarrolló una púrpura reactiva por una infección por Strongyloides stercoralis crónica. Ante ello, es posible el compromiso cutáneo en pacientes inmunocompetentes con reagudización sistémica por este parásito.

Infection with Strongyloides stercoralis is a common parasitic infection in tropical and subtropical regions, including the Peruvian Amazon. The clinical manifestations are varied in patients with immunocompromised disease, and the systemic spread of the disease is frequent, compromising different organs and systems. Cutaneous manifestations are infrequent, being described in patients with some degree of immunosuppression. We present the case of an immunocompetent patient who developed a reactive purpura due to chronic Strongyloides stercoralis infection. Thus, skin involvement is possible in immunocompetent patients with systemic exacerbation due to this parasite.

Treatment options for demodex blepharitis: patient choice and efficacy.

BACKGROUND: Demodex mites are microscopic parasites that live around hair follicles or sebaceous glands and may cause chronic blepharitis. The aim of this outcome analysis was to assess the efficacy and patient preferences with regard to the currently recommended treatment options. METHODS: All patients with microscopic evidence for Demodex blepharitis were informed about the currently published treatments and instructed about daily lid hygiene. Additional topical treatment options included tea tree oil (TTO) 5%, a cleansing foam containing 0.02% TTO (Naviblef®), and metronidazole 2% ointment. Systemic treatment options included oral ivermectin 6 mg on day 1 and 14 and metronidazole 500 mg twice daily for 10 days. All patients were reviewed after 2 months for symptoms and for a mite count on 10 epilated lashes. RESULTS: Ninety-four of 96 patients with Demodex blepharitis opted for an additional treatment. The mean mite count after 2 months of treatment were 13.3 with 5% TTO (n=6), 12.0 with 0.02% TTO (n=38), 9.4 with metronidazole ointment (n=5), 12.8 with ivermectin (n=27) and 22.0 with oral metronidazole (n=5). CONCLUSION: While there are several published treatment options available, none of these options seem to be clearly effective in Demodex blepharitis.

An ethnopharmacological assessment of the use of plants against parasitic diseases in humans and animals.

ETHNOPHARMACOLOGICAL RELEVANCE: Ethnobotanical surveys are detecting an increasing frequency of exotic plant species in pharmacopeias, which has led researchers to investigate the role of such species in traditional medical systems. According to the diversification hypothesis, exotic species are included to complete pharmacopeias, i.e., to treat diseases for which no native species are known, thus broadening the scope of the plant repertoire. MATERIALS AND METHODS: The present study was conducted at two rural communities in northeastern Brazil aiming at a survey of the plants known or used by the population to treat endo- and ectoparasitic diseases in humans and animals. In addition, plant extracts exhibiting acaricide activity were assessed using the engorged female immersion and larval packet tests (LPT). RESULTS: The results of the present study showed a tendency for native species to be used against ectoparasites and exhibit a broader scope of use compared to exotic species. In turn, exotic species were predominantly indicated to treat diseases caused by endoparasites, although there was an overlap of native and exotic species relative to some therapeutic purpose, e.g., ticks. Only two of the plant species tested exhibited acaricide activity (Nicotiana glauca Graham and Croton blanchetianus Baill.), and in both cases, the activity was weak. CONCLUSION: The ethnobotanical data do not fully support the suggested hypothesis. Overall, the wide versatility of exotic species was not exclusively used to treat parasitic diseases in humans and animals. In addition, the selection of acaricide plants based on the ethnopharmacological study generated uninteresting results.

Assay and physicochemical characterization of the antiparasitic albendazole

The aim of this study was to characterize three batches of albendazole by pharmacopeial and complementary analytical techniques in order to establish more detailed specifications for the development of pharmaceutical forms. The ABZ01, ABZ02, and ABZ03 batches had melting points of 208 ºC, 208 ºC, and 209 ºC, respectively. X-ray diffraction revealed that all three batches showed crystalline behavior and the absence of polymorphism. Scanning electron microscopy showed that all the samples were crystals of different sizes with a strong tendency to aggregate. The samples were insoluble in water (5.07, 4.27, and 4.52 mg mL-1, respectively) and very slightly soluble in 0.1 M HCl (55.10, 56.90, and 61.70 mg mL-1, respectively) and additionally showed purities within the range specified by the Brazilian Pharmacopoeia 5th edition (F. Bras. V; 98% to 102%). The pharmacopeial assay method was not reproducible and some changes were necessary. The method was validated and showed to be selective, specific, linear, robust, precise, and accurate. From this characterization, we concluded that pharmacopeial techniques alone are not able to detect subtle differences in active pharmaceutical ingredients; therefore, the use of other complementary techniques is required to ensure strict quality control in the pharmaceutical industry.

O objetivo do trabalho foi caracterizar três lotes de albendazol com técnicas analíticas farmacopéicas e complementares a fim de estabelecer especificações mais detalhadas para o desenvolvimento de formas farmacêuticas. Os lotes ABZ01, ABZ02 e ABZ03 apresentaram fusão em 208 ºC, 208 ºC e 209 ºC. Foi possível evidenciar, por difração de raios X, que os três lotes apresentaram comportamento cristalino e ausência de polimorfismo. Através da microscopia eletrônica de varredura verificou-se que todas as amostras apresentaram cristais com diferentes tamanhos e forte tendência de agregação. As amostras foram insolúveis em água (5,07; 4,27 e 4,52 µg mL-1) e muito pouco solúveis em HCl 0,1M (55,10; 56,90 e 61,70 µg mL-1) e, ainda, apresentaram pureza dentro da faixa especificada pela F.Bras.V (98% a 102%). O método farmacopéico de doseamento não foi reprodutível, e algumas mudanças foram necessárias. O método foi validado e demonstrou ser seletivo, específico, linear, robusto, preciso e exato. A partir dessa caracterização, pode-se concluir que apenas técnicas farmacopéicas não são capazes de detectar diferenças sutis entre os ingredientes farmacêuticos ativos, necessitando, portanto, de uso de outras técnicas complementares para garantir um rígido controle de qualidade na indústria farmacêutica.

Identification of a host cell target for the thiazolide class of broad-spectrum anti-parasitic drugs.

The thiazolide nitazoxanide (NTZ) and some derivatives exhibit considerable in vitro activities against a broad range of parasites, including the apicomplexans Neospora caninum and Toxoplasma gondii tachyzoites. In order to identify potential molecular targets for this compound in both parasites, RM4847 was coupled to epoxy-agarose and affinity chromatography was performed. A protein of approximately 35 kDa was eluted upon RM4847-affinity-chromatography from extracts of N. caninum-infected human foreskin fibroblasts (HFF) and non-infected HFF, but no protein was eluted when affinity chromatography was performed with T. gondii or N. caninum tachyzoite extracts. Mass spectrometry analysis identified the 35 kDa protein as human quinone reductase NQO1 (P15559; QR). Within 8h after infection of HFF with N. caninum tachyzoites, QR transcript expression levels were notably increased, but no such increase was observed upon infection with T. gondii tachyzoites. Treatment of non-infected HFF with RM4847 did also lead to an increase of QR transcript levels. The enzymatic activity of 6-histidine-tagged recombinant QR (recQR) was assayed using menadione as a substrate. The thiazolides NTZ, tizoxanide and RM4847 inhibited recQR activity on menadione in a concentration-dependent manner. Moreover, a small residual reducing activity was observed when these thiazolides were offered as substrates.

[Antiparasitic drugs. Review of the useful drugs in the treatment of classic and emergent parasitic diseases]. / Antiparasitarios. Revisión de los fármacos útiles en el tratamiento de parasitosis clásicas y emergentes.

INTRODUCTION: In the 10 last years, the increase of international travels and immigration from low income countries to Spain was related with an increased of prevalence of parasitic diseases. SOURCE: Critical review of the literature. STRUCTURE: Firstly, several general considerations were made on the antiparasitic drugs revised in this paper. Chemical structures and mechanisms of action of the main drugs with antiparasitic effect were considered in the second part of the review. Further, antiparasitic spectrum of selected drugs, main pharmacokinetical characteristics, usual posology, possible side effects and contraindications were detailed. Finally, some practical aspects, such as interactions and the methods for practical obtention of these drugs are indicated. This information is relevant because in Spain many anti-parasitic drugs may be obtained using non conventional methods. CONCLUSION: In Spain, the increase of parasitic diseases necessitates an update on antiparasitics drugs for their treatment.

Assessment of chronic toxicity and carcinogenicity in an accelerated cancer bioassay in rats of Nifurtimox, an antitrypanosomiasis drug.

The chronic toxicity and carcinogenicity of Nifurtimox (NFX), a 5-nitrofuran derivative used in the treatment of American trypanosomiasis, were studied in male and female Wistar rats in an accelerated cancer bioassay (ACB). The ACB is a mechanistic initiation/promotion chronic toxicity and carcinogenicity bioassay designed to assess potential carcinogenic activity of a test substance in critical organs and tissues of rodents in which human carcinogens are active. The organs studied were liver, lungs, urinary bladder (UB), mammary gland (MG), bone marrow, spleen, kidneys, colon, stomach and any grossly observed lesions. NFX is a genotoxin which has been reported previously to exert a variable degree of carcinogenic activity in rat liver, kidney, UB and MG. The present study was undertaken to assess whether NFX has initiating activity in these four named target sites. In the initiation phase, groups of 20 Wistar rats were given NFX daily in the diet at 0.2% for the first 12 weeks of the study to assess initiating activity, followed by promoters (PROs) for four organs for an additional 24 weeks. NFX was compared to the following known initiators (INs) for each of these four tissues: diethylnitrosamine (DEN) for liver and kidney, N-butyl-N(4-hydroxybutyl)nitrosamine (BBN) for UB and 7,12-dimethylbenz(a)anthracene (DMBA) for MG. PROs included phenobarbital (PB) for liver and kidney, nitrilotriacetic acid (NTA) for UB, and diethylstilbestrol (DES) for MG. NFX was also administered continuously without PROs for 40 weeks. At the end of dosing (40 weeks) and at the end of recovery (52 weeks), animals were sacrificed and subjected to complete gross and histopathological examinations, along with evaluations of body weight gain over time and terminal body weights. Mortality was highest with DEN+PB (group 6) (40%), followed by BBN+NTA (group 7) (15%) and NFX+DES (group 5) and DMBA+DES (group 8) (10% each). The same groups also showed significant reductions in body weight gain over time and terminal body weights at sacrifice. In these groups, the expected preneoplastic, neoplastic and metastatic neoplastic lesions were produced, demonstrating the sensitivity of the model. In groups given NFX+PROs (groups 3-5), either no neoplasms occurred (group 4) or only single neoplasms (groups 3 and 5). In contrast, the PROs all elicited tumors in groups given INs (groups 6-8). Also, NFX given alone for 40 weeks did not produce any chronic toxicity, preneoplastic or neoplastic lesions. Thus, in this study, NFX did not demonstrate chronic toxicity or carcinogenicity. Moreover, in four target sites, i.e., liver, kidney, UB and MG, it exhibited no neoplastic initiating activity manifested by PROs for these four target sites.

Pediculicide drug products for over-the-counter human use; amendment of final monograph. Final rule.

The Food and Drug Administration (FDA) is issuing a final rule amending the final monograph (FM) for over-the-counter (OTC) pediculicide drug products to revise labeling for the statement of identity, warnings, directions, and other required statements. Pediculicide drug products are used for the treatment of head, pubic (crab), and body lice. FDA is issuing this final rule as part of its ongoing review of OTC drug products after considering public comment on its proposed regulation and all relevant data and information that have come to the agency's attention.

Tratamiento de las enteroparasitosis / Intestinal parasites treatment

La parasitosis intestinal es un grave problema de salud mundial que afecta al 50% de los habitantes de América Latina en especial a los países con pobres recursos económicos. En este trabajo describimos las principales drogas utilizadas para el tratamiento de las infecciones parasitarias más comunes en nuestro país, así como su práctico y fácil manejo, basado en nuestra experiencia y la de destacados profesores nacionales y del exterior.

Intestinal parasitosis is a serious health problem wich affects 50% of the Latin American population, in special on countries with poor economic resources. In this work we present the description of the principal available drugs which are used in the treatment of the parasitic infections in our country, as well as, their practical and easy management as a result of our experience and those of other autors.