Manejo de hemorragia asociada a anticoagulantes orales directos: estado actual de las estrategias de reversión / Management of bleeding associated with direct oral anticoagulants: update on reversal strategies

Direct oral anticoagulants (DOACs), including the direct thrombin inhibitor dabigatran and the direct factor Xa inhibitors rivaroxaban, apixaban and edoxaban have at least comparable efficacy as vitamin K antagonists along with a better safety profile, reflected by a lower incidence of intracranial hemorrhage. Specific reversal agents have been developed in recent years. Namely, idarucizumab, a specific antidote for dabigatran, is currently approved in most countries. Andexanet, which reverses factor Xa inhibitors, has been recently approved by the FDA, and ciraparantag, a universal antidote targeted to reverse all DOACs, is still under investigation. In this review we provide an update on the pharmacology of DOACs, the risk of hemorrhagic complications associated with their use, the measurement of their anticoagulant effect and the reversal strategies in case of DOAC-associated bleeding.

Use of direct oral anticoagulants for chronic thromboembolic pulmonary hypertension

OBJECTIVES: Chronic thromboembolic pulmonary hypertension is one of the most prevalent forms of pulmonary hypertension and is a major complication of acute pulmonary embolism. One mainstay of chronic thromboembolic pulmonary hypertension treatment is lifelong anticoagulation. The recent advent of direct oral anticoagulants for acute pulmonary embolism treatment has provided a viable and effective alternative for treating this condition. However, little is known about the efficacy of this new class of drugs for treating chronic thromboembolic pulmonary hypertension. We aimed to evaluate the safety and efficacy of direct oral anticoagulants in the treatment of chronic thromboembolic pulmonary hypertension. METHODS: A cohort of chronic thromboembolic pulmonary hypertension patients who initiated treatment with direct oral anticoagulants between June 2015 and November 2016 were enrolled in this study. RESULTS: Sixteen patients used rivaroxaban, three used dabigatran and one used apixaban for a mean follow-up of 20.9 months. The mean age was 51 years, and eighteen patients were classified as functional class II/III. Eight patients underwent a pulmonary endarterectomy and exhibited clinical, hemodynamic and functional improvement and currently continue to use direct oral anticoagulants. No episode of venous thromboembolism recurrence was identified during the follow-up period, but there was one episode of major bleeding after a traumatic fall. CONCLUSIONS: Although direct oral anticoagulants appear to be a safe and effective alternative for treating chronic thromboembolic pulmonary hypertension, larger studies are needed to support their routine use.

Celecoxib decreases growth and angiogenesis and promotes apoptosis in a tumor cell line resistant to chemotherapy

BACKGROUND: During the last few years it has been shown in several laboratories that Celecoxib (Cx), a non-steroidal anti-inflammatory agent (NSAID) normally used for pain and arthritis, mediates antitumor and antiangiogenic effects. However, the effects of this drug on a tumor cell line resistant to chemotherapeutical drugs used in cancer have not been described. Herein we evaluate the angiogenic and antitumor effects of Cx in the development of a drug-resistant mammary adenocarcinoma tumor (TA3-MTXR). RESULTS: Cx reduces angiogenesis in the chick embryonic chorioallantoic membrane assay (CAM), inhibits the growth and microvascular density of the murine TA3-MTXR tumor, reduces microvascular density of tumor metastases, promotes apoptosis and reduces vascular endothelial growth factor (VEGF) production and cell proliferation in the tumor. CONCLUSION: The antiangiogenic and antitumor Cx effects correlate with its activity on other tumor cell lines, suggesting that Prostaglandins (PGs) and VEGF production are involved. These results open the possibility of using Celecoxib combined with other experimental therapies, ideally aiming to get synergic effects.

New orally active anticoagulants in critical care and anesthesia practice: The good, the bad and the ugly.

With the adoption of dabigatran, rivaroxaban, and apixaban into clinical practice, a new era has arrived in the practice of oral anticoagulants. Venous thromboembolism (VTE) has traditionally been underdiagnosed and under treated in Asia. With increasing longevity, the diagnosis and the need for management of atrial fibrillation (AF) and VTE is likely to increase significantly. The new orally active anticoagulants (NOACs) have reasonably filled the lacunae that clinicians traditionally faced when treating patients with vitamin K antagonist (VKA). Unlike VKA, NOACs do not need frequent monitoring. Therefore, more patients are likely to get therapeutic effects of anticoagulation and thus reduce morbidity and mortality associated with VTE and AF. However, the clinicians need to be circumspect and exercise caution in use of these medications. In particular (in geriatric population), the clinicians should look out for drug-drug interactions and underlying renal insufficiency. This would ensure therapeutic efficacy and minimize bleeding complications. Here, it is important to note that the antidote for NOACs is not available and is a major concern if emergency surgical procedure is required in their presence.

Association between baseline VEGF/sVEGFR-2 and VEGF/TSP-1 ratios and response to metronomic chemotherapy using cyclophosphamide and celecoxib in patients with advanced breast cancer.

BACKGROUND: Metronomic chemotherapy (MCT) with cyclophosphamide (Cy) and celecoxib (Cel) has therapeutic efficacy and low toxicity profile in advanced breast cancer patients (ABCP), but no reliable biomarkers of response have been found yet that allow patient selection for treatment. AIM: To investigate the potential role as biomarkers of pro‑ and antiangiogenic parameters and evaluate their response in ABCP receiving metronomic Cy 50 mg p.o./day + Cel 400 mg p.o./day. MATERIALS AND METHODS: Serum levels of vascular endothelial growth factor‑C (VEGF‑C), soluble VEGF receptors 2 and 3 (sVEGFR‑2, sVEGFR‑3), were measured at different time points in 13/15 patients included in a phase II trial of MCT with Cy+Cel. RESULTS: Serum levels of sVEGFR‑2 and sVEGFR‑3 increased significantly during treatment (P = 0.0392; P = 0.0066, respectively). VEGF‑C showed no significant modifications. Previous determinations of VEGF and TSP‑1 in the same patients were utilized. VEGF/sVEGFR‑2, VEGF/TSP‑1, and VEGF‑C/sVEGFR‑3 ratios decreased significantly along the treatment (P = 0.0092; P = 0.0072; P = 0.0141, respectively). Nonsignificant variations were observed for VEGF‑C/sVEGFR‑2 ratio. Baseline values of VEGF/sVEGFR‑2 and VEGF/TSP‑1 ratios were associated with time to progression (TTP) (P = 0.0407; P = 0.0394, respectively) meanwhile baseline VEGF was marginally significant (P = 0.0716). Patients with values lower than the 50th percentile for both ratios showed longer TTP. CONCLUSIONS: We have identified the baseline VEGF/sVEGFR‑2 and VEGF/TSP‑1 ratios as potential biomarkers of response in ABCP treated metronomically with Cy+Cel. This finding warrants its confirmation in a higher number of patients.

Acaricidal efficacy of topical formulation of fipronil in naturally infested dogs in Amazonic region, Brazil / Eficácia carrapaticida de fipronil tópico em cães naturalmente infestados na região amazônica, Brasil

This study was conducted to show the effectiveness of a novel formulation of fipronil in a spot-on formulation for the therapeutic and preventive control of Rhipicephalus sanguineus in naturally infested dogs. Ticks on all dogs were counted at the moment of treatment and weekly after treatment (therapeutic efficacy) or infestation (preventive efficacy). The profile of the therapeutic efficacy for Rhipicephalus sanguineus suggested that the formulation was able to control the Ixodid species for at least 42 days after the treatment.

Este estudo teve como objetivo avaliar a eficácia de uma nova formulação "spot-on" à base de fipronil na terapêutica e prevenção do parasitismo por Rhipicephalus sanguineus em cães naturalmente infestados. Foi realizada contagem dos carrapatos no momento da aplicação do produto e semanalmente após o tratamento (eficácia terapêutica), bem como avaliando sua reinfestação (eficácia preventiva). Perfis terapêuticos e preventivos sugerem que a formulação controla o parasitismo por R. sanguineus em cães por pelo menos 42 dias após o tratamento.

Nuevos anticoagulantes orales en la prevención del ataque cerebrovascular / New oral anticoagulants in stroke prevention

Introduction: Atrial fibrillation (AF) is the most common arrhythmia. AF increases stroke risk by 5-fold and accounts for 15 percent of stroke. For more than 50 years, vitamin K antagonists were the only available oral anticoagulation. The two major classes of novel oral agents are direct thrombin inhibitors (dabigatran) and factor Xa inhibitors (apixaban or rivaroxaban). These new agents require no routine laboratory monitoring and they are administered in a fixed dose. Method: A non systematic literature review was performed. Results: We performed a critical review of articles about new oral anticoagulants in stroke prevention. We evaluated properties of these agents and we compare efficacy and safety outcomes shown in clinical trials about new oral anticoagulants in AF. Discussion: New oral anticoagulants are at least as good as warfarin at preventing stroke in patients with AF. They seem to be safer than warfarin with significantly less intracranial bleeding. Trials demonstrate dabigatran to be the most effective in decreasing ischemic strokes, apixaban superior to warfarin with statistically lower mortality, and rivaroxaban no worse than warfarin for those with higher stroke risk. Conclussion: New oral anticoagulants have several advantages in comparison with warfarin, but we need further trials to know better the efficacy and safety of these new agents.

Introducción: La fibrilación auricular (FA) es la arritmia más frecuente, se asocia a un riesgo 5 veces mayor de ataque cerebrovascular (ACV), y da cuenta del 15 por ciento de los ACV isquémicos. Por más de medio siglo el tratamiento anticoagulante oral en FA ha estado limitado al uso de antagonistas de la vitamina K. Los nuevos anticoagulantes orales, se clasifican en dos categorías principales: inhibidores de la trombina como el dabigatrán y los inhibidores del factor Xa, como el apixabán y el rivaroxabán. Estos fármacos no requieren monitorización de los niveles de anticoagulación y se administran en dosis fija. Método: Revisión no sistemática de la literatura. Resultados: Se analizan de manera crítica los artículos sobre nuevos anticoagulantes orales en la prevención de ACV. Se evalúan las propiedades de estos nuevos agentes y se comparan los desenlaces de eficacia y de seguridad de los ensayos clínicos de los estos fármacos. Discusión: Los nuevos anticoagulantes orales son al menos tan efectivos que la warfarina en la prevención de ACV cardioembólico en pacientes con FA. Parecen ser más seguros con menor frecuencia de hemorragia intracranial. El dabigatrán es el más efectivo en disminuir el ACV isquémico, el apixabán es superior a la warfarina con una mortalidad significativamente inferior, y el rivaroxabán es no inferior a warfarina para pacientes con alto riesgo de ACV. Conclusión: Los nuevos anticoagulantes orales ofrecen varias ventajas en comparación a warfarina, sin embargo, se requiere se estudios adicionales para conocer más detalladamente su efectividad y perfil de seguridad.

Cyclooxygenase-2 inhibitors modulate skin aging in a catalytic activity-independent manner

It has been proposed that the pro-inflammatory catalytic activity of cyclooxygenase-2 (COX-2) plays a key role in the aging process. However, it remains unclear whether the COX-2 activity is a causal factor for aging and whether COX-2 inhibitors could prevent aging. We here examined the effect of COX-2 inhibitors on aging in the intrinsic skin aging model of hairless mice. We observed that among two selective COX-2 inhibitors and one non-selective COX inhibitor studied, only NS-398 inhibited skin aging, while celecoxib and aspirin accelerated skin aging. In addition, NS-398 reduced the expression of p53 and p16, whereas celecoxib and aspirin enhanced their expression. We also found that the aging-modulating effect of the inhibitors is closely associated with the expression of type I procollagen and caveolin-1. These results suggest that pro-inflammatory catalytic activity of COX-2 is not a causal factor for aging at least in skin and that COX-2 inhibitors might modulate skin aging by regulating the expression of type I procollagen and caveolin-1.

Uso combinado da laserterapia de baixa potência e da inibição da ciclooxigenase-2 na reepitelização de ferida incisional em pele de camundongos: um estudo pré-clínico / Combined use of low level laser therapy and cyclooxygenase-2 selective inhibition on skin incisional wound reepithelialization in mice: a preclinical study

FUNDAMENTOS: A laserterapia de baixa potência e os inibidores seletivos da ciclooxigenase-2 (ICOX2) vem sendo muito utilizados para modular a resposta inflamatória, entretanto, os seus efeitos na reepitelização de feridas não são bem compreendidos. OBJETIVO: Avaliar os efeitos isolados e combinados da laserterapia de baixa potência e da ICOX2 na reepitelização de ferida incisional na pele de camundongos. MÉTODO: Foi induzida uma ferida de 1 cm no dorso de cada camundongo, que foram divididos em quatro grupos (N=20): Controle, Laserterapia, Tratados com celecoxib e Terapia conjugada. Os animais dos grupos celecoxib e Terapia conjugada foram tratados com celecoxib por 10 dias antes da incisão cutânea. As feridas experimentais foram irradiadas com laserterapia de baixa potência He-Ne (632nm, dose: 4J/cm2) em varredura, por 12 segundos durante três dias consecutivos nos grupos Laserterapia e Terapia conjugada. Os animais foram sacrificados no 3º dia de pós-operatório. Amostras das feridas foram coletadas e coradas (Tricromio de Masson) para análise histomorfométrica. RESULTADOS: Tanto o grupo Laserterapia, quanto o grupo celecoxib, mostrou aumento da reepitelização cutânea em relação ao grupo Controle, entretanto, o grupo Terapia conjugada não apresentou diferenças. Quanto à queratinização o grupo Laserterapia e Terapia conjugada apresentaram redução dos queratinócitos, comparados com o grupo Controle. CONCLUSÕES: Os resultados mostram que o uso da laserterapia de baixa potência e da ICOX2 isoladamente aumentam as células epiteliais, mas somente a laserterapia de baixa potência reduziu os queratinócitos cutâneos. O tratamento conjugado restabelece a reepitelização inata e dimunui a queratinização, embora ocorra uma acelerada contração da ferida com melhora na organização da ferida na pele de camundongos.

BACKGROUND: Low level laser therapy and cyclooxygenase-2 (ICOX2) selective inhibitors have been widely used to modulate inflammatory response; however, their effect on wound reepithelialization are not well understood. OBJECTIVE: To evaluate the isolated and combined effects of low level laser therapy and ICOX2 in the reepithelization of skin incisional wounds in mice. METHODS: We induced a 1-cm wound on the back of each mouse, which were divided into four groups (N = 20): control, laser therapy, treated with celecoxib and combined therapy. The animals in the celecoxib and combined therapy groups were treated with celecoxib for 10 days before skin incision. The experimental wounds were irradiated with He-Ne low power laser (632nm, dose: 4J/cm2) in scanning for 12 seconds during three consecutive days in the laser therapy and combined therapy groups. The animals were sacrificed 3 days after surgery. Samples of the wounds were collected and stained (Masson's Trichrome) for histomorphometric analysis. RESULTS: Both the laser therapy group and the celecoxib group showed an increase in skin reepithelialization compared to the control group; however, the combined therapy group showed no differences. As for keratinization, the laser therapy and combined therapy groups showed a reduction in keratinocytes compared with the control group. CONCLUSION: The results show that the use of low level laser therapy and ICOX2 in isolation increases epithelial cells, but only low level laser therapy reduced skin keratinocytes. The combined treatment restores innate epithelialization and decreases keratinization in spite of accelerating wound contraction with improvement in the organization of the wound in the skin of mice.

Eficácia comparativa de duas formulações de uso tópico contendo fipronil 10 por cento no controle de Ctenocephalides felis felis em gatos / Comparative efficacy of two topical formulations containing 10 percent fipronil on the control of Ctenocephalides felis felis on cats

No presente trabalho, foram avaliadas, comparativamente, duas formulações comerciais tópicas, contendo 10 por cento de fipronil, para o controle da pulga Ctenocephalides felis felis em gatos. O experimento foi realizado no Laboratório de Quimioterapia Experimental em Parasitologia Veterinária do Departamento de Parasitologia Animal, Instituto de Veterinária, da Universidade Federal Rural do Rio de Janeiro. Foram empregados 18 gatos, sem raça definida, divididos em três grupos de seis. Um grupo permaneceu sem tratamento (controle), e os demais foram medicados com uma formulação referência do mercado veterinário ou com uma nova formulação em teste. Os animais tratados receberam 0,5 mL do produto ao longo da região dorso-cervical e foram infestados nos dias - 2, +5, +12, +19, +26 e +33. A primeira avaliação foi realizada quatro dias após a primeira infestação e, as demais, 48 horas após cada infestação, por meio do comb test. Ambas as formulações testadas foram eficazes até o dia +35 após o tratamento, não havendo diferenças entre seus níveis de eficácia ao longo do período experimental. A nova formulação, contendo fipronil a 10 por cento, apresentou a eficácia desejada no controle de C. f. felis em gatos.

The goal of the present study was to evaluate the comparative efficacy of two topical formulations containing 10 percent fipronil on the control of Ctenocephalides felis felis on cats. The trial was performed at the Laboratory of Experimental Chemotherapy in Veterinary Parasitology from the Department of Animal Parasitology of the Institute of Veterinary of the Universidade Federal Rural do Rio de Janeiro. Eighteen mixed-breed cats were divided in three groups of six animals each. One group remained without treatment (control). The other groups received as treatment the two topical formulations, a commercial reference and the novel one, both containing 10 percent fipronil. Treated animals received 0.5 mL of product along their cervical region. Cats were infested on days - 2, +5, +12, +19, +26 and +33. Evaluations were made using the "comb test". The first one was undertaken 4 days after the initial infestation (day +2), and others 48 hours after following infestations (days +7, +14, +21, +28 and + 35). Both tested formulations had satisfactory efficacy until day + 35. No differences were observed comparing the efficacy levels between both formulations troughout the experimental period. The novel topical 10 percent fipronil formulation presented desirable efficacy on the control of C. f. felis on cats.

A Case of Complete Regression of Hepatocellular Carcinoma during Administration of COX-2 Inhibitor / 대한간학회지

Overexpression of cyclooxygenase-2 (COX-2) has been associated with hepatocarcinogenesis. Inhibitors of COX-2 have proapoptotic and antiproliferative effects on malignant tumors and inhibit tumor invasion to the surrounding tissues. We report here a case of complete regression of advanced hepatocellular carcinoma (HCC) during COX-2 inhibitor administration. An eighty-year-old female was diagnosed as an advanced HCC, which was associated with HCV infection. She received COX-2 inhibitor for 3 months due to degenerative arthritis of both knees. Tumor enhancement on arterial phase CT completely disappeared without specific treatment for the HCC, and the tumor size decreased on the follow-up CT scan.

Laboratory evaluation of fipronil against Periplaneta americana & Blattella germanica.

BACKGROUND & OBJECTIVE: In cockroach control, bait formulations are extensively used. Fipronil is one of the broad spectrum insecticides from phenyl pyrazole family available in bait formulation. The compound has been tested under field conditions. However, information on its effectiveness on different surfaces and at various density levels is not known. Therefore, the efficacy of a new formulation of fipronil 0.03 per cent (Goliath gel) was tested under laboratory conditions. METHODS: The bait formulation was tested against Periplaneta americana at the dosages of 0.025, 0.05, 0.1, 0.15 and 0.2 g/m(2), and Blatella germanica at 0.025, 0.05, 0.075, 0.1 and 0.125 g/m(2) on wood, cement, mud and thatch surface with three density levels of cockroaches viz., 5, 10 and 20 numbers/m(2). Mortality after 24 h of exposure was observed daily for five days. RESULTS: Rate of mortality varied between 16.0 and 96.0 per cent in P. americana and 51.0 and 100.0 per cent in B. germanica on different surfaces tested. The mortality rate of P. americana increased line rarly from the dosage 0.025g to 0.15 g/m(2) and at 0.2 g/m(2), it was independent. The LD(80) values of the gel against P. americana at high density were 0.208, 0.246, 0.361 and 0.466 g/m(2) on wood, cement, mud and thatch surfaces, whereas against B. germanica the values were 0.079, 0.081, 0.089 and 0.055 g/m(2) respectively, indicating a significantly (P<0.001) higher efficacy of Goliath gel against B. germanica than P. americana. The results of fitting logistic regression model to the observed percentage mortality with log dose and cockroach density as explanatory variables satisfactorily described the observations at all densities on each surface. The pattern of response to increasing dosages was similar for all the three density levels on each of the surfaces in P. americana and B. germanica. INTERPRETATION & CONCLUSION: The effectiveness assessed against P. americana and B. germanica using logistic regression model suggested that the gel when applied at the appropriate dosages on wood, cement, mud and thatch surfaces could cause >80 per cent mortality of these species in dwellings having these types of surfaces.

Clinical pharmacokinetic of celecoxib in healthy Thai volunteers.

BACKGROUND: Celecoxib, a nonsteroidal antiinflammatory drug exhibits its antiinflammatory effect by selective inhibition of cyclooxygenase-2 (COX-2) enzyme. Its efficacy has been accepted for the treatment of arthritic pain with superior gastrointestinal side effect profile compared with other conventional NSAIDs. OBJECTIVE: To elucidate clinical pharmacokinetic of celecoxib following an oral dose administration. MATERIAL AND METHOD: Eighteen healthy Thai male volunteers were enrolled in the present study. Their mean age was 20.94 +/- 1.21 years and their mean weight was 63 +/- 5.17 kg. They were orally administered 200 mg celecoxib after an over night fasting, serial blood samples were drawn before and at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 10, 12, 24 and 48 hours after dosing. Plasma celecoxib was analysed by reversed-phase HPLC. RESULTS: Following a 200 mg celecoxib oral administration, the drug was absorbed into the systemic circulation and reach maximum concentration (Tmax) within 2.50 +/- 1.22 hrs by average with the mean peak concentration (Cmax) of 686.83 +/- 211.35 ng/ml. The extent of absorption (area under the curve, AUC) was approximately 5157.12 +/- 1499.46 and 5911.48 +/- 1363.51 ng hr/ml for AUC(0-->t) and AUC(0-->infinity) respectively. The apparent volume of distribution (Vd) was found to be 458.93 +/- 323.28 L/hr. Celecoxib was eliminated after biotransformation and the metabolites were excreted in both urine and feces. The elimination half-life (t(1/2)) of celecoxib appeared to be 8.79 +/- 5.49 hrs with the apparent clearance (CL) of 35.91 +/- 9.85 L. The elimination rate constant for celecoxib obtained from this present study was about 0.11 +/- 0.05 hr(-1). CONCLUSION: Pharmacokinetic parameters following an oral dose of 200 mg celecoxib administration were characterized, including Cmax, Tmax, Vd, kel, CL, AUC. These parameters reflected absorption, distribution, biotransformation and excretion of celecoxib in healthy Thai volunteers.

Antinociceptive property of new 4-acyl-arylhydrazone pyrazole compounds

A series of new 4-acyl-arylhydrazone pyrazole compunds were tested for antinociceptive activity using the inhibition of abdominal contortions induced by acetylcholine (4 mg/Kg, ip) in the mouse. Dipyrone was used for comparison of the antinociceptive potency of the compounds being tested. All drugs wee administered po in saline (dipyrone) or in propylene flycol 94-acyl-arylhydrazones). The maximum response induced by dipyrone (86% inhibition) was assigned an efficacy index of 1.0. Although none of the compounds had an efficacy index greater than 1.0, all three reached 1.0. The two most potent compounds, Wd1 and W1g, which also had an efficacy similar to that of dipyrone, contain a p-N(CH3)2 and m-OH,p-OCH3 group in the aromatic ring of the acyl-hydrazone, respectively. W1d presented the lowest antinociceptive ED50 in the series (1.41 mg/Kg) and was eleven times more potent than dypyrone (ED50 = 15.80 mg/Kg). Other substitutions at the para position had lower potency than W1d. The present results indicate that the introduction of a group at the para postion of the acyl-arylhydrazone ring increases the antinociceptive activity of these compounds to provide compounds of the same efficacy but greater potency than dipyrone to which these new compounds ara structurally related. Other assays of nociceptive activity are veing used to characterize the mechanism of action of the potential new drugs

The effects of Bendaline(R) on cataracts

A double blind multicenter study of patients suffering from presenile and senile cataracts was performed, bendazac Iysine salt (Bendaline(R))or a placebo was administered orally to the patients and the results were analyzed. Although subjective variability in visual acuity and in the clinical course of cataracts should be taken into consideration together with the short duration of the observation period, the results obtained demonstrate an improvement in the Bendaline(R) treated group with regard to visual acuity and lens opacity, and an aggravation in the group of patients receiving the placebo.