Profile, performance, and perception of pharmacist preparedness for the COVID-19 pandemic.

INTRODUCTION: The lack of human resources for disease prevention and control is evident in times of health crisis, such as the COVID-19 pandemic. In public health emergencies, the capacity for adequate assistance and guaranteed access to pharmacological treatment are fundamental and contribute to impact reduction. We aimed to analyze the profile, performance, and characteristics related to the self-perception of preparedness among pharmacists who responded to the COVID-19 pandemic in Brazil. METHOD: A cross-sectional study was conducted in two stages: content validation of a questionnaire and its application to a representative sample of pharmacists in Rio de Janeiro. The snowball technique was used to recruit participants. A logistic regression model was adjusted to determine the effects of the factors on the probability of a pharmacist feeling prepared to act during the pandemic. RESULTS: Six experts approved and validated the questionnaire, and 376 pharmacists were included in the study, 60.6 % of whom were in places specially designated by health authorities to diagnose and treat COVID-19. Professionals participated in various activities related to pandemic demands, including medication management and population guidance. Postgraduate degrees increased the odds of participants feeling prepared to act during the pandemic. Furthermore, pharmacists who worked in reference facilities were more likely to feel ready than those who worked in other places. Professionals who knew treatment guidelines were almost three times more likely to feel prepared than the ones without the knowledge of treatment guidelines. Training or guidance on how to act during the pandemic increased pharmacists' odds of feeling prepared by 2.58 times. CONCLUSION: Pharmacists actuated from diagnosis to treatment and participated in the health activities required during the pandemic. Factors contributing to the self-perception of preparedness were identified. Such factors can be targets for interventions to promote the preparedness of the workforce for future health emergencies.

Consumption of drugs for Alzheimer's disease on the Brazilian private market.

OBJECTIVE: To analyze the consumption of drugs for Alzheimer's disease on the Brazilian private market and its geographical distribution from 2014 to 2020. METHODS: National data from the Brazilian National System of Controlled Product Management were used, regarding sales of donepezil, galantamine, rivastigmine, and memantine from January 2014 to December 2020. Sales data were used as a proxy for drug consumption and expressed as defined daily dose/1,000 inhabitants/year at national, regional, federative unit and microregion levels. RESULTS: Drug consumption went from 5,000 defined daily doses/1,000 inhabitants, in 2014, to more than 16,000/1,000 inhabitants, in 2020, and all federative units showed positive variation. The Brazilian Northeast had the highest cumulative consumption in the period but displayed microregional disparities while the North region had the lowest consumption. Donepezil and memantine were the most consumed drugs, with the highest growth in consumption from 2014 to 2020. CONCLUSION: The consumption of medicines indicated to treat Alzheimer's disease tripled in Brazil between 2014 and 2020, which may relate to the increase in the prevalence of the disease in the country, greater access to health services, and inappropriate use. This challenges managers and healthcare providers due to population aging and the increased prevalence of chronic-degenerative diseases.

Consumption of drugs for Alzheimer's disease on the Brazilian private market / Consumo de medicamentos para doença de Alzheimer no mercado privado brasileiro

ABSTRACT OBJECTIVE To analyze the consumption of drugs for Alzheimer's disease on the Brazilian private market and its geographical distribution from 2014 to 2020. METHODS National data from the Brazilian National System of Controlled Product Management were used, regarding sales of donepezil, galantamine, rivastigmine, and memantine from January 2014 to December 2020. Sales data were used as a proxy for drug consumption and expressed as defined daily dose/1,000 inhabitants/year at national, regional, federative unit and microregion levels. RESULTS Drug consumption went from 5,000 defined daily doses/1,000 inhabitants, in 2014, to more than 16,000/1,000 inhabitants, in 2020, and all federative units showed positive variation. The Brazilian Northeast had the highest cumulative consumption in the period but displayed microregional disparities while the North region had the lowest consumption. Donepezil and memantine were the most consumed drugs, with the highest growth in consumption from 2014 to 2020. CONCLUSION The consumption of medicines indicated to treat Alzheimer's disease tripled in Brazil between 2014 and 2020, which may relate to the increase in the prevalence of the disease in the country, greater access to health services, and inappropriate use. This challenges managers and healthcare providers due to population aging and the increased prevalence of chronic-degenerative diseases.

RESUMO OBJETIVO Analisar o consumo de medicamentos para a doença de Alzheimer no mercado privado brasileiro e sua distribuição geográfica entre os anos de 2014 e 2020. MÉTODOS Foram utilizados dados do Sistema Nacional de Gerenciamento de Produtos Controlados relativos às vendas de donepezila, galantamina, rivastigmina e memantina, entre janeiro de 2014 a dezembro de 2020, em todo o território nacional. Os dados de venda foram utilizados como proxy para o consumo dos medicamentos, avaliado em dose diária definida (DDD)/1.000 habitantes/ano em nível nacional, regional, por unidade federativa e microrregião. RESULTADOS O consumo dos medicamentos passou de 5.000 DDD/1.000 habitantes em 2014 para mais de 16.000 DDD/1.000 habitantes em 2020, e todas as unidades de federação apresentaram variação positiva. A região Nordeste apresentou o maior consumo acumulado no período, porém exibiu disparidades microrregionais. A região Norte apresentou o menor consumo. Os medicamentos mais consumidos foram donepezila e memantina, os quais também apresentaram maior crescimento do consumo no intervalo de tempo entre os anos de 2014 e 2020. CONCLUSÃO O consumo de medicamentos para o tratamento da doença de Alzheimer triplicou no Brasil entre os anos de 2014 e 2020, o que pode estar relacionado ao aumento da prevalência da doença no país e/ou maior acesso a serviços de saúde, assim como estar ligado, também, à utilização inapropriada destes medicamentos. Este é um desafio para gestores e profissionais de saúde num cenário de envelhecimento populacional e aumento da prevalência de doenças crônico-degenerativas.

Use of therapeutic outcomes monitoring method for performing of pharmaceutical care in oncology patients.

This study aimed to implement pharmaceutical care using the therapeutic outcome monitoring (TOM) method for pharmacotherapeutic follow-up of oncological patients. This was a prospective longitudinal study involving patients undergoing oral chemotherapy. The study environment was an outpatient pharmacy at a tertiary-level oncology hospital. Ninety patients who received oral chemotherapy were evaluated, and 27 patients were followed up in accordance with the exclusion criteria and acceptability of participation in the study. The patients were predominantly diagnosed with gynecological tumors, with a mean age of 57.56 ± 13.06. The average consumption of drugs per patient was 4.63 ± 4.85, and more than 55% of patients had undergone oral antineoplastic therapy for more than a year. The main therapeutic groups used were drugs that acted on the gastrointestinal tract and metabolism (34%). All patients had at least one drug-related problem (DRP). In total, 133 DRP were identified. Approximately 33% of patients had DRPs related to antineoplastic therapy; non-adherence, incorrect administration, and the probability of adverse events were among the frequently reported DRPs. We identified 43 negative outcomes associated with medication (NOM), with untreated health problems (47%) and non-quantitative insecurity (30%) being the most frequently reported. 81 pharmaceutical interventions were performed, and 96% were accepted. The main errors avoided with the interventions were untreated health problems, misuse, and interruptions associated with medication administration. The TOM method effectively achieved the desired results of therapy, improving the use of medicines, and thus increasing patient safety.

In Vivo and In Vitro Taste Assessment of Artesunate-Mefloquine, Praziquantel, and Benznidazole Drugs for Neglected Tropical Diseases and Pediatric Patients.

The assessment of drug taste is crucial for pediatric treatments so that formulations can be developed to enhance their effectiveness. In this study, in vivo and in vitro methods were applied to evaluate the taste of tablets of three drugs administered to children without taste-masking excipients to treat tropical diseases, namely artesunate-mefloquine (ASMQ), praziquantel (PZQ), and benznidazole (BNZ). In the first method, a model of rat palatability was adapted with recirculation to ensure sample dispersion, and the data were analyzed using ANOVA (single factor, 95%). The taste assessment results (in vivo) indicated an aversion to the three medicines, denoted by the animals retracting themselves to the bottom of the box after the first contact with the drugs. For the placebo samples, the animals behaved normally, indicating that taste perception was acceptable. The second method was based on the in vitro analysis of capacitance data from a homemade impedimetric electronic tongue. Consistent with the in vivo taste assessment results, the data points obtained with PZQ, ASMQ, and BNZ were far away from those of their placebos in a map built with the multidimensional projection technique referred to as Interactive Document Mapping (IDMAP). A combined analysis of the results with the two methods allowed us to confirm the bitterness of the three drugs, also pointing to electronic tongues as a promising tool to replace in vivo palatability tests.

Investigation of a Microemulsion Containing Clotrimazole and Itraconazole for Transdermal Delivery for the Treatment of Sporotrichosis.

The aim of this study was to develop a microemulsion (ME) formulation containing an association of itraconazole (ITC) and clotrimazole (CLT) as a transdermal delivery system for the treatment of sporotrichosis. Pseudoternary phase diagrams were constructed to optimize the ME formulation. The ME formulation selected contained 1% (w/w) ITC and 1% (w/w) CLT and was composed of 23.07% Tween® 60 (surfactant), 23.07% propylene glycol (cosurfactant/cosolvent), 30.77% benzyl alcohol (oil), and 21.09% water. The ITC/CLT-loaded ME (ITC/CLT-ME) had a droplet size value of 217 ± 0.9 nm, with a polydispersity index of 0.5 ± 0.1. Permeation experiments on pig ear skin were conducted for ITC/CLT-ME, and the results indicated that the drug permeation performance was influenced by CLT, indicating that CLT acts as a promoter enhancer. In the in vitro antifungal activity assay using Sporothrix brasiliensis yeast, the inhibition halo produced by ITC/CLT-ME exhibited a mean diameter of 43.67 ± 2.31 mm. The ITC/CLT-ME formulation did not cause skin irritation in mice. The results suggest that ITC/CLT-ME is a promising tool for the transdermal treatment of sporotrichosis.

Cuidado farmacêutico domiciliar na Estratégia Saúde da Família / Home Pharmaceutical Care in the Family Health Strategy

Resumo Este trabalho desenvolveu e avaliou uma ferramenta para auxiliar no planejamento, execução, registro de dados e avaliação das ações da visita domiciliar farmacêutica na equipe de Estratégia Saúde da Família. A primeira fase consistiu na construção da ferramenta de visita domiciliar farmacêutica, através de grupo focal e análise de discurso. Discutiu-se a visão dos profissionais sobre o papel do farmacêutico e sua prática profissional, em especial na visita domiciliar em unidades de atenção primária à saúde. Na segunda fase, utilizou-se o formulário desenvolvido na etapa anterior durante a visita domiciliar por 32 farmacêuticos, e avaliaram-se adequação, clareza, efetividade/precisão, exequibilidade e sugestões para a ferramenta. Todos os participantes do estudo efetivamente realizam visita domiciliar na Estratégia de Saúde da Família no município do Rio de Janeiro. Segundo avaliação expressiva dos participantes, o instrumento foi considerado adequado, claro, efetivo, preciso e exequível para utilização na prática de visita domiciliar; representando importante auxílio ao profissional na realização do cuidado farmacêutico domiciliar naquele município.

Abstract This work developed and evaluated a tool to assist in the planning, execution, data recording and evaluation of the actions of the pharmaceutical home visit in the Family Health Strategy team. The first phase comprised the construction of the pharmaceutical home visit tool, through a focus group and discourse analysis. The professionals' view on the role of the pharmacist and his professional practice was discussed, especially in home visits in primary health care units. In the second phase, the form developed in the previous step was used during the home visit by 32 pharmacists, and adequacy, clarity, effectiveness / precision, feasibility and suggestions for the tool were evaluated. All study participants effectively perform home visits in the Family Health Strategy in the city of Rio de Janeiro. According to an expressive evaluation of the participants, the instrument was considered adequate, clear, effective, precise and feasible for use in the practice of home visits, and is an important assistance to the professional in performing home pharmaceutical care in that city.

Análise de interações medicamentosas em prescrições pediátricas de um centro de tratamento de queimados / Analysis of drug interactions in pediatric prescriptions in a burn care unit

OBJETIVO: Esse estudo tem por objetivo analisar as interações medicamentosas em prescrições de pacientes pediátricos do Centro de Tratamento de Queimados. MÉTODO: Trata-se de um estudo analítico de orientação retrospectiva, com análise das prescrições quanto à segurança e interações medicamentosas. As interações medicamentosas foram classificadas de acordo com a gravidade da interação. Das interações classificadas como contraindicadas, foi analisado o prontuário para avaliar a ocorrência de relato de alteração clínica devido à interação medicamentosa. RESULTADOS: Das 805 prescrições analisadas, 435 (54,04%) continham pelo menos uma interação medicamentosa, apresentando média de quatro interações por prescrição. Foram encontradas 1828 interações com medicamentos, que corresponderam a 84 combinações entre 43 fármacos. A classificação de gravidade encontrada foi: 96 (5,25%) contraindicadas, 1077 (58,92%) importantes, 452 (24,73%) moderadas e 203 (11,11%) secundárias. As interações contraindicadas estavam presentes em prescrições de cinco pacientes. Em apenas um prontuário foi encontrado relato de evento adverso compatível com a interação medicamentosa encontrada. Com relação à avaliação da prescrição, os itens identificação do paciente, instituição e prescritor estavam presentes em mais de 80%. Observou-se média de 9,5 medicamentos por prescrição. CONCLUSÃO: A maioria das prescrições dos pacientes pediátricos internados no centro de tratamento de queimados apresentaram interações medicamentosas. Isso provavelmente ocorreu devido ao grande número de medicamentos prescritos.

OBJECTIVE: This study aims to analyze the drug interactions in prescriptions of pediatric patients from the Center for the Burn Treatment. METHODS: It is an analytical retrospective study that analyzed prescriptions regarding safety and drug interactions. The drug interactions were classified according to interaction severity. From drug interactions classified as contraindicated, the patients chart was evaluated to assess whether there was clinical change due to drug interaction found. RESULTS: Of the 805 prescriptions analyzed, 435 (54.04%) contained at least one drug interaction, presenting an average of four interactions per prescription. One thousand eight hundred twenty-eight drug interactions were found, which corresponded to 84 combinations between 43 drugs. The severity classification was: 96 (5.25%) contraindicated, 1077 (58.92%) important, 452 (24.73%) moderate and 203 (11.11%) secondary. The contraindicated interactions were present in the prescriptions of five patients. Only one chart was found, an adverse event report compatible with the drug interaction found. Regarding the evaluation of the prescription, the items related to identifying the patient, institution and prescriber were present in more than 80%. It was observed an average of 9.54 drugs per prescription. CONCLUSION: Most of the prescriptions for pediatric patients admitted to the burn treatment center presented drug interactions; this probably occurred due to many prescribed drugs.

Predictors of adverse drug reactions associated with ribavirin in direct-acting antiviral therapies for chronic hepatitis C.

PURPOSE: To identify factors associated with the development of adverse drug reactions (ADR) in ribavirin therapeutic regimens. METHODS: A multicenter, prospective study was conducted in three public health hospitals in Rio de Janeiro between November 2015 and March 2018. Inclusion criteria were defined by patient follow-up at pharmaceutical consultation at the time of drug dispensing as those who used sofosbuvir in combination with simeprevir, daclatasvir, and/or ribavirin. All patients were invited to participate in the study during the first interview. Adverse drug reactions were reported according to the treatment regimen and frequency of occurrence. Statistical analysis was used to compare adverse reactions between treatments and their associated factors. RESULTS: A total of 405 patients were included in the study (mean age 59.6 ± 9.6 years); 61.0% were female, 88.1% were infected with genotype 1, and 65.4% were cirrhotic. The most prescribed treatment was the combination of sofosbuvir, daclatasvir, and ribavirin (55.3%). The majority of patients reported at least one ADR during treatment (83.2%), of which fatigue, anemia, and headache were the most common. Being female (OR = 1.86, [1.08-3.20]) and use of ribavirin (OR: 2.39; 95% CI [1.38-4.13]) were predictors for the development of ADR, which was also associated with development of anemia (OR: 10.28; 95% CI: [5.78-18.30]). Treatment efficacy was 98.1%. CONCLUSIONS: Direct-acting antiviral has been shown to be safe and effective. Therefore, use of ribavirin is questionable due to associated adverse reactions and similar efficacy to other treatments.

Preclinical pharmacokinetic evaluation of praziquantel loaded in poly (methyl methacrylate) nanoparticle using a HPLC-MS/MS.

Praziquantel (PZQ) is the drug recommended by the World Health Organization for treatment of schistosomiasis. However, the treatment of children with PZQ tablets is complicated due to difficulties to adapt the dose and the extremely bitter taste of PZQ. For this reason, poly (methyl methacrylate) nanoparticles loaded with Praziquantel (PZQ-NP) were developed for preparation of a new formulation to be used in the suspension form. For this reason, the main aim of the present study was to evaluate the pharmacokinetic (PK) profile of PZQ-NP, through HPLC-MS/MS assays. Analyses were performed with an Omnisphere C18 column (5.0 µm×4.6 mm×150.0 mm), using a mixture of an aqueous solution containing 0.1 wt% of formic acid and methanol (15:85-v/v) as the mobile phase at a flow rate of 0.800mL/min. Detection was performed with a hybrid linear ion-trap triple quadrupole mass spectrometer with multiple reactions monitoring in positive ion mode via electrospray ionization. The monitored transitions were m/z 313.18>203.10 for PZQ and m/z 285.31>193.00 for the Internal Standard. The method was validated with the quantification limit of 1.00 ng/mL, requiring samples of 25 µL for analyses. Analytic responses were calibrated with known concentration data, leading to correlation coefficients (r) higher than 0.99. Validation performed with rat plasma showed that PZQ was stable for at least 10 months when stored below -70 °C (long-term stability), for at least 17 h when stored at room temperature (RT, 22 °C) (short-term stability), for at least 47 h when stored at room temperature in auto-sampler vials (post-preparative stability) and for at least 8 successive freeze/thaw cycles at -70 °C. For PK assays, Wistar rats, weighing between 200 and 300 g were used. Blood samples were collected from 0 to 24 h after oral administration of single doses of 60 mg/kg of PZQ-NP or raw PZQ (for the control group). PZQ was extracted from plasma by liquid-liquid extraction with terc-butyl methyl ether. The values obtained for maximum concentration (C(max)) and area under curve (AUC) for the PZQ-NP group were about 3 times smaller than the respective values obtained for the control group. However, the time for achieving maximum concentration (T(max)), the elimination constant (Ke) and the half-life time of elimination (T(½ß)) were not statistically different. These results suggest that PZQ absorption is probably the rate-limiting step for obtainment of better PK parameters for PZQ-NP. Thus, further studies are needed to understand both the PZQ-NP absorption mechanisms and the drug diffusion process through the polymer matrix in vivo, in order to improve the PZQ-NP release profile.

Occurrence of sulfated fucose branches in fucosylated chondroitin sulfate are essential for the polysaccharide effect preventing muscle damage induced by toxins and crude venom from Bothrops jararacussu snake.

Snake envenoming is an important public health problem around the world, particularly in tropics. Beyond deaths, morbidity induced by snake venoms, such as myotoxicity, is of pivotal consequence to population. Bothrops jararacussu is the main venomous snake in southeast region of Brazil, and particularly presents strong myotoxic effect. The only available therapy, antibothropic antivenom, poorly affects venom-induced myotoxicity. The aim of this study is to assess the ability of fucosylated chondroitin sulfate (fucCS), a glycosaminoglycan with anticoagulant and antithrombotic properties, and its derivatives to inhibit toxic activities of B. jararacussu crude venom and its isolated toxins, named bothropstoxins (BthTX-I and BthTX-II). The in vitro myotoxic activities induced by crude venom, by BthTX-I alone and by toxins together were abolished by fucCS. Carboxyl reduction (fucCS-CR) kept this ability whereas defucosilation (defucCS) abrogates myoprotection. We observed the same pattern in the response of these polysaccharides in antagonizing the increase in plasma creatine kinase (CK) levels, the reduction of skeletal muscle CK content and the rise of myeloperoxidase (MPO) activity induced by crude venom and isolated toxins. FucCS inhibited edematogenic activity and partially prevented the reduction of total leukocytes in blood when pre-incubated with crude venom. Furthermore, the venom procoagulant effect was completely antagonized by increasing concentrations of fucCS, although this polyanion could stop neither the tail bleeding nor the skin hemorrhage induced by Bothrops jararaca venom. The B. jararacussu phospholipase, hyaluronidase, proteolytic and collagenase activities were inhibited in vitro. The results suggest that fucCS could be able to interact with both toxins, and it is able to inhibit BthTX-II phospholipase activity. Light microscopy of extensor digitorum longus muscle (EDL) muscle showed myoprotection by fucCS, once necrotic areas, edema and inflammatory cells were all decreased as compared to venom injection alone. Altogether, data show that fucCS was able to inhibit myotoxicity and inflammation induced by B. jararacussu venom and its phospholipase toxins, BthTX-I and BthTX-II. Thus, fucosylated chondroitin sulfate is a new polyanion with potential to be used as an adjuvant in the treatment of snakebites in the future.

Adverse reactions to docetaxel: an active survey

The rates of breast cancer mortality remain high in Brazil. Docetaxel is a semi-synthetic taxane used to treat various tumors, particularly tumors of the breast, lung and prostate. In this study ADR that occurred in 45 docetaxel users with breast cancer were surveyed. They were identified by type, causality (Naranjo algorithm and World Health Organization categories) and, if considered probable or defined, rated for severity according to SOBRAFO proposal (2007). A total of 325 ADR were observed: 165 in the first, 137 in the second and 23 in the third cycle. Fifty seven ADR were immediate and the others, late. Fatigue and exhaustion for more than five days, classified as Grade 3 by SOBRAFO (2007), were reported as the primary late RAM. There was no significant difference in the occurrence of immediate and late ADR between cycles (p=1 and p=0.3577, respectively). The presence of a pharmacist gave the patients a better understanding of the occurrence of RAM, especially those that occur outside the hospital, between chemotherapy cycles and are often not reported to the healthcare team, creating institutional demands and reaching the goal to track, observe and correlate the RAM for each user.

As taxas de mortalidade por câncer de mama no Brasil permanecem altas. O docetaxel é um taxano semi-sintético usado para tratar vários tumores, particularmente tumores da mama, pulmão e próstata. Neste estudo, as Reações Adversas (RAM) ocorridas em 45 pacientes com câncer de mama foram monitoradas. Elas foram classificadas pelo tipo e causalidade (Algoritmo de Naranjo e categorias propostas pela Organização Mundial da Saúde) e, se consideradas prováveis ou definidas, foram classificadas também pela severidade, de acordo com a proposta da SOBRAFO (2007). Um total de 325 RAM foram observadas: 165 no primeiro, 137 no segundo e 23 no terceiro ciclo. Cinquenta e sete RAM foram imediatas e as demais tardias. Fadiga e exaustão por mais de 5 dias, classificadas como grau 3 pela SOBRAFO (2007), foram as principais RAM encontradas. Não houve diferença significativa na ocorrência de RAM imediatas ou tardias entre os ciclos (p=1 e p=0,3577, respectivamente). A presença de um farmacêutico proporcionou aos pacientes um melhor entendimento sobre a ocorrência de RAM, especialmente sobre aquelas que ocorrem fora do ambiente hospitalar, entre os ciclos da terapia, não sendo usualmente relatadas aos profissionais de saúde. Isto gerou uma demanda na instituição e permitiu alcançar a meta de acompanhar, observar e correlacionar as RAM de cada paciente.

Neutralization of Apis mellifera bee venom activities by suramin.

In this work we evaluated the ability of suramin, a polysulfonated naphthylurea derivative, to antagonize the cytotoxic and enzymatic effects of the crude venom of Apis mellifera. Suramin was efficient to decrease the lethality in a dose-dependent way. The hemoconcentration caused by lethal dose injection of bee venom was abolished by suramin (30 µg/g). The edematogenic activity of the venom (0.3 µg/g) was antagonized by suramin (10 µg/g) in all treatment protocols. The changes in the vascular permeability caused by A. mellifera (1 µg/g) venom were inhibited by suramin (30 µg/g) in the pre- and posttreatment as well as when the venom was preincubated with suramin. In addition, suramin also inhibited cultured endothelial cell lesion, as well as in vitro myotoxicity, evaluated in mouse extensor digitorum longus muscle, which was inhibited by suramin (10 and 25 µM), decreasing the rate of CK release, showing that suramin protected the sarcolemma against damage induced by components of bee venom (2.5 µg/mL). Moreover, suramin inhibited the in vivo myotoxicity induced by i.m. injection of A. mellifera venom in mice (0.5 µg/g). The analysis of the area under the plasma CK vs. time curve showed that preincubation, pre- and posttreatment with suramin (30 µg/g) inhibited bee venom myotoxic activity in mice by about 89%, 45% and 40%, respectively. Suramin markedly inhibited the PLA2 activity in a concentration-dependent way (1-30 µM). Being suramin a polyanion molecule, the effects observed may be due to the interaction of its charges with the polycation components present in A. mellifera bee venom.

Dexamethasone antagonizes the in vivo myotoxic and inflammatory effects of Bothrops venoms.

In the present work we investigated the toxic activities of two Bothrops snake venoms using in vivo and in vitro experimental protocols in mice and tested the protective effect of dexamethasone (DEXA) in different conditions, comparing it with the polyvalent antivenom. We also expanded the investigations on the antiophidic effect of the Eclipta prostrata (EP) crude extract. The administration of Bothrops jararaca and Bothrops jararacussu snake venoms induced muscle damage demonstrated in vivo by the elevation on plasma creatine kinase (CK) activity in mice and by the decrease in CK content in the extensor digitorum longus (EDL) muscle of these animals, and in vitro by the increase in the rate of CK release from the isolated EDL muscle. We also observed inflammatory response following perimuscular injection of B. jararacussu venom (1.0 mg/kg). Treatment with DEXA (1.0 mg/kg) preserved over 50% of the EDL muscle CK content in vivo when evaluated 24 and 72 h after the injection of B. jararacussu venom in mice, and likewise reduced about 20% of the edema induced by this venom. DEXA reduced in 50% the presence of inflammatory cells and their activity in EDL muscle. The EP extract (50 mg/kg) showed similar ability in preventing the induction of edema and the decrease in muscle CK content, and its association with DEXA showed additive effect. EP reduced over 77% of the plasma CK activity induced by the B. jararacussu venom. In the in vitro experiments, DEXA was not able to change the rate of CK release from EDL muscles exposed to 25 µg/mL of B. jararacussu venom, neither to prevent the fall in the amplitude of the indirectly evoked twitch at the phrenic-diaphragm preparation. EP extract showed otherwise a protective effect on these protocols, reaching up to 100% of protection when concentrations of 50.0 and 100.0 µg/mL were used. Altogether our results show that inflammation is at least in part responsible for the tissue damage induced by Bothrops snake venoms, once the steroidal anti-inflammatory drug dexamethasone was able to decrease the myotoxic effects of these venoms, by reducing the inflammatory response to the venom injection.

Ability of a synthetic coumestan to antagonize Bothrops snake venom activities.

We investigated a synthetic coumestan named LQB93 and similar compounds abilities to antagonize activities of Bothrops jararacussu and Bothrops jararaca crude venoms in different protocols. The antimyotoxic activity was evaluated in vitro by the rate of release of creatine kinase (CK) from isolated mouse extensor digitorum longus muscle (EDL) induced by B. jararacussu (25 g/ml). For in vivo studies, B. jararacussu venom (1.0 mg/kg) was preincubated with LQB93 (0.1-30 mg/kg), during 30 min, for later injection in mouse tight and evaluation of the antimyotoxic and anti-edematogenic effects. LQB93 antagonized in vitro, the increase of CK release from the EDL muscle (IC(50)=0.0291 M). It also showed in vivo, antimyotoxic and anti-edematogenic effects that were dose-dependent with ID50 of 0.17 mg/kg and 0.14 mg/kg, respectively. The hemorrhage induced by B. jararaca (1.0 mg/kg) venom in the mouse skin, was abolished by LQB93 (10.0 mg/kg) preincubated with venom. Like wedelolactone, LQB93 protected rat isolated heart on a Langendorff preparation, from the cardiotoxicity of B. jararacussu venom. LQB93 inhibit the effects of Bothrops venoms like wedelolactone, a natural compound isolated from the plant Eclipta prostrata.

Effect of heparin treatment on the expression and activity of different ion-motive P-type ATPase isoforms from mouse extensor digitorum longus muscle during degeneration and regeneration after Bothrops jararacussu venom injection.

Ca(2+) ions are essential to myonecrosis, a serious complication of snake envenomation, and heparin seems to counteract this effect. We investigated the effect of local injection of Bothrops jararacussu venom in mouse fast-twitch extensor digitorum longus (EDL) muscle, without or with heparin, on functional/molecular alterations of two central proteins involved in intracellular Ca(2+) homeostasis, sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) and Na(+)/K(+)-ATPase. EDL-specific SERCA1 isoform expression dropped significantly just after venom administration (up to 60% compared to control EDL values at days 1 and 3; p<0.05) while SERCA2 and Na(+)/K(+)-ATPase alpha(1) isoform expression increased at the same time (3-6- and 2-3-fold, respectively; p<0.05). Although not significant, Na(+)/K(+)-ATPase alpha(2) isoform followed the same trend. Except for SERCA2, all proteins reached basal levels at the 7th day. Intravenous heparin treatment did not affect these profiles. Ca(2+)-ATPase activity was also decreased during the first days after venom injection, but here heparin was effective to reinstate activity to control levels within 3 days. We also showed that B. jararacussu venom directly inhibited Ca(2+)-ATPase activity in a concentration-dependent manner. Our results indicate that EDL SERCA and Na(+)/K(+)-ATPase are importantly affected by B. jararacussu venom and heparin has protective effect on activity but not on protein expression.

Increase of the cytotoxic effect of Bothrops jararacussu venom on mouse extensor digitorum longus and soleus by potassium channel blockers and by Na(+)/K(+)-ATPase inhibition.

We investigated the myotoxicity of Bothrops jararacussu crude venom and other cytolytic agents on mouse isolated extensor digitorum longus (EDL) and soleus (SOL) muscles, which present distinct properties: EDL is a fast-twitch, white muscle with predominantly glycolytic fibers, while SOL is slow-twitch, red muscle with predominantly oxidative fibers. Muscles were exposed to B. jararacussu crude venom (25 microg/ml) and other crotaline venoms (Agkistrodon contortrix laticinctus; Crotalus viridis viridis; Crotalus durissus terrificus) at the same concentration. Basal creatine kinase (CK) release to bathing solution was 0.43+/-0.06 for EDL and 0.29+/-0.06 for SOL (U g(-)(1) h(-)(1), n=36 for each muscle). Sixty minutes after exposure to B. jararacussu venom, EDL presented higher increase in the rate of CK release than SOL, respectively, 13.2+/-1.5 and 2.9+/-0.7 U g(-)(1)h(-)(1), n=10-12. Muscle denervation, despite decreasing CK content, did not affect sensitivities to B. jararacussu venom. Ouabain and potassium channel blockers (TEA; clotrimazole; glibenclamide) increased the rate of CK release by B. jararacussu in EDL and SOL muscles, decreasing and almost abolishing the different sensitivity. When we exposed EDL or SOL muscles to Naja naja, Apis mellifera venoms (25 microg/ml), or Triton X-100 (0.01%), they showed similar rate of CK release. Our present data suggest that a mechanism involving intracellular calcium regulation or potassium channels may participate in the different sensitivity of EDL and SOL to B. jararacussu venom.

Ability of suramin to antagonize the cardiotoxic and some enzymatic activities of Bothrops jararacussu venom.

We have investigated the cardiotoxic effect of Bothrops jararacussu crude venom and the ability of suramin to antagonize this effect in the heart of rats, as well as the proteolytic and phospholipase A(2) (PLA(2)) venom activities. Continuous perfusion in an isolated heart of a rat on a Langendorff preparation with a Ringer's solution with B. jararacussu crude venom (2.5-10.0 microg/mL) induces stoppage and a decrease in the cardiac tension, which were time- and concentration dependent. The analysis of the heart perfusate solution showed an increase in the rate of creatine kinase induced by the venom. Pre-incubation with suramin (1.0-30.0 microM) protected against the venom cardiotoxic effect in a concentration-dependent way, reaching up to 90% with 30.0 microM, and prevent the heart stoppage and decrease the tension. These protective effects were increased by the association with polyvalent antibothropic antivenom, suggesting a synergic effect. The PLA(2) and proteolytic activities of B. jararacussu crude venom were also inhibited in a concentration-dependent way by suramin, showing that this polyanion antivenom activity has therapeutic potential to be used as an antivenom.

Inhibition of myotoxic activity of Bothrops asper myotoxin II by the anti-trypanosomal drug suramin.

Suramin, a synthetic polysulfonated compound, developed initially for the treatment of African trypanosomiasis and onchocerciasis, is currently used for the treatment of several medically relevant disorders. Suramin, heparin, and other polyanions inhibit the myotoxic activity of Lys49 phospholipase A2 analogues both in vitro and in vivo, and are thus of potential importance as therapeutic agents in the treatment of viperid snake bites. Due to its conformational flexibility around the single bonds that link the central phenyl rings to the secondary amide backbone, the symmetrical suramin molecule binds by an induced-fit mechanism complementing the hydrophobic surfaces of the dimer and adopts a novel conformation that lacks C2 symmetry in the dimeric crystal structure of the suramin-Bothrops asper myotoxin II complex. The simultaneous binding of suramin at the surfaces of the two monomers partially restricts access to the nominal active sites and significantly changes the overall charge of the interfacial recognition face of the protein, resulting in the inhibition of myotoxicity.