Treatment of acute ischaemic stroke with thrombolysis or thrombectomy in patients receiving anti-thrombotic treatment

Systemic thrombolysis with alteplase is the only approved medical treatment for patients with acute ischaemic stroke. Thrombectomy is also increasingly used to treat proximal occlusions of the cerebral arteries, but has not shown superiority over systemic thrombolysis with alteplase. Many patients with acute ischaemic stroke are pretreated with antiplatelet or anticoagulant drugs, which can increase the bleeding risk of thrombolysis or thrombectomy. Pretreatment with aspirin monotherapy increases the bleeding risk of alteplase in both observational and randomised trials with no effect on clinical outcome, and the risk of intracerebral haemorrhage is increased with the combination of aspirin and clopidogrel. Antiplatelet drugs should not be given in the first 24 h after alteplase treatment. Data from pooled randomised trials and a large observational study show that thrombolysis can probably be done safely in patients given vitamin-K antagonists if the international normalised ratio is less than 1·7, although bleeding risk is slightly raised. Almost no data are available for the safety of alteplase in patients with atrial fibrillation who have been given novel oral anticoagulants (NOAC) for stroke prevention. Some coagulation parameters could help to identify patients treated with NOAC who might be eligible for thrombolysis. Thrombectomy can be done in patients given antiplatelets and probably in those given anticoagulants; however, conclusions about anticoagulants are based on findings from observational studies with small patient numbers.

Heparin-induced thrombocytopenia: some working hypotheses on pathogenesis, diagnostic strategies and treatment

PURPOSE OF REVIEW: The present contribution will illustrate some evolving concepts on the pathogenesis and clinical management of heparin-induced thrombocytopenia (HIT) and describe how we approach patients with suspected HIT at our institution. RECENT FINDINGS: HIT is caused by an autoimmune reaction leading to the formation of antibodies directed against platelet factor 4. Conditions favoring the development of anti-platelet factor 4/heparin antibodies differ from those required for the formation of macromolecular ternary complexes (HIT antibody/platelet factor 4/heparin), which are able to activate platelets and induce clinical HIT. HIT can be diagnosed by combining its pretest probability with the quantitative result of rapid HIT-antibody assays. Treatment of acute HIT requires inhibition of in-vivo thrombin generation by means of alternative nonheparin anticoagulant drugs, whose effective dosage appears to be significantly lower than the official recommendations. As HIT antibodies are transient, HIT patients can be re-exposed to heparin, provided that previous heparin treatment is remote and that anti-platelet factor 4/heparin antibodies are undetectable. SUMMARY: In recent years, there has been a continuing elucidation of pathogenic and clinically relevant issues, which are intellectually rewarding to follow and should enable us to offer a steadily improving treatment to the HIT patients we are in charge of.

Major bleeding of the upper aerodigestive tract due to oral anticoagulant/antibiotic interactions

INTRODUCTION Although a well-known complication in certain medical specialties, major bleeding due to the interaction between oral anticoagulants and antibiotics has been rarely reported concerning the upper aerodigestive tract. We report three cases of life-threatening bleeding of the upper aerodigestive tract in a context of antibiotic therapy in patients treated with oral anticoagulants. CASE SERIES Three male patients under coumadin anticoagulation therapy presented major bleeding in three different contexts (epistaxis, peritonsillar abscess and postoperative course after total laryngectomy). Surgical intervention for hemostasis was required in all cases, with coagulation correction in two. Complications were severe anemia (2/3) and chronic heart failure (1/3). DISCUSSION/CONCLUSIONS Interactions between two drugs commonly used in otolaryngology can result in major bleeding. The goal of this article is to raise practitioners' awareness of a potentially fatal, although rare, complication. We also review the main preventive strategies.

Developing drugs for use before, during and soon after percutaneous coronary intervention.

INTRODUCTION Percutaneous coronary intervention (PCI) is a milestone for treating coronary artery disease (CAD). Antithrombotic therapy is essential to prevent ischemic complications, including the microvascular no-reflow, while minimizing bleeding events. Areas covered: This overview discusses available and developing drugs for PCI including anticoagulants, antiplatelets and treatment of no-reflow. Expert opinion: For years unfractionated heparin (UFH) has been the unique anticoagulant to be used before and during PCI. Enoxaparin showed similar efficacy and safety, yet, based on recent trials, bivalirudin has been shown to have some benefits, particularly for patients with ST-segment elevation myocardial infarction (STEMI). The evidence concerning new anticoagulants is still preliminary, except for new oral anticoagulants, particularly rivaroxaban that showed intriguing findings and is currently under investigation. Dual antiplatelet therapy (DAPT) is the standard of care after PCI, but new developments have recently emerged. Indeed, ticagrelor and prasugrel are currently recommended over clopidogrel due to their significant reduction of ischemic events in acute coronary syndrome (ACS) whereas clopidogrel remains the choice in stable CAD. Among new agents, vorapaxar and cangrelor showed positive but limited evidence and might be considered at least in selected patients. Conversely, evidence on effective treatments for no-reflow remains limited and would require future dedicated research.

Screening for lupus anticoagulant: improving the performance of the lupus-sensitive PTT-LA

Introduction: The aim of the present work was to verify whether calculating a ratio between clotting times obtained with the sensitive PTT-LA and a less sensitive activated partial thromboplastin time (aPTT)-reagent may represent a valuable aPTT-based screening strategy for lupus anticoagulants (LA). Methods: For the pilot study, plasma samples from normal subjects (n = 15) and from patients with LA (n = 10), therapeutic anticoagulation with vitamin K-antagonists (VKA) (n = 15) or unfractionated heparin (n = 15), coagulation factors deficiency (n = 16), and inhibitory antibodies against factor VIII or IX (n = 11) were studied. For the evaluation study, 1553 consecutive plasma samples from nonanticoagulated patients investigated for LA between January 2005 and December 2007 at our institution were studied. Following screening strategies were employed: Pathromtin-SL (aPTT-SL), PTT-LA (aPTT-LA), ratio aPTT-LA/aPTT-SL (aPTT-ratio), and Russell's viper venom (RVV) based LA-Check. LA positive samples were identified by mixing studies and diluted RVV confirmation test (LA-Check/LA-Sure). Results: Pilot study: All screening strategies had a 100% sensitivity, and the aPTT-ratio reached the highest specificity (82%; 95%CI: 74-90%). Within the evaluation study, following sensitivities for LA screening were observed: aPTT-SL 59.0% (95%CI: 57-61%), aPTT-LA 82.1% (95%CI: 80-84%), aPTT-ratio 92.3% (95%CI: 91-94), and LA-Check 83.3% (95%CI: 82-85%). Conclusion: Calculating a ratio between the LA-sensitive PTT-LA and the less sensitive Pathromtin-SL improves the performance of the PTT-LA itself and represents a simple and sensitive aPTT-based integrated strategy for LA screening.

Synergistic induction of cell death in liver tumor cells by TRAIL and chemotherapeutic drugs via the BH3-only proteins Bim and Bid

Although death receptors and chemotherapeutic drugs activate distinct apoptosis signaling cascades, crosstalk between the extrinsic and intrinsic apoptosis pathway has been recognized as an important amplification mechanism. Best known in this regard is the amplification of the Fas (CD95) signal in hepatocytes via caspase 8-mediated cleavage of Bid and activation of the mitochondrial apoptosis pathway. Recent evidence, however, indicates that activation of other BH3-only proteins may also be critical for the crosstalk between death receptors and mitochondrial triggers. In this study, we show that TNF-related apoptosis-inducing ligand (TRAIL) and chemotherapeutic drugs synergistically induce apoptosis in various transformed and untransformed liver-derived cell lines, as well as in primary human hepatocytes. Both, preincubation with TRAIL as well as chemotherapeutic drugs could sensitize cells for apoptosis induction by the other respective trigger. TRAIL induced a strong and long lasting activation of Jun kinase, and activation of the BH3-only protein Bim. Consequently, synergistic induction of apoptosis by TRAIL and chemotherapeutic drugs was dependent on Jun kinase activity, and expression of Bim and Bid. These findings confirm a previously defined role of TRAIL and Bim in the regulation of hepatocyte apoptosis, and demonstrate that the TRAIL-Jun kinase-Bim axis is a major and important apoptosis amplification pathway in primary hepatocytes and liver tumor cells.

Controversies in cardiovascular medicine: Chronic stable coronary artery disease: drugs vs. revascularization

Coronary artery disease remains the leading cause of mortality in most industrialized countries, although age-standardized mortality related to coronary artery disease (CAD) has decreased by more than 40% during the last two decades. Coronary atherosclerosis may cause angina pectoris, myocardial infarction, heart failure, arrhythmia, and sudden death. Medical management of atherosclerosis and its manifestation aims at retardation of progression of plaque formation, prevention of plaque rupture, and subsequent events and treatment of symptoms, when these occur as well as treatment of the sequelae of the disease. Revascularization by either percutaneous coronary intervention (PCI) or coronary artery bypass surgery (CABG) is performed as treatment of flow-limiting coronary stenosis to reduce myocardial ischaemia. In high-risk patients with acute coronary syndromes (ACS), a routine invasive strategy with revascularization in most patients provides the best outcome with a significant reduction in death and myocardial infarction compared with an initial conservative strategy. Conversely, the benefit of revascularization among patients with chronic stable CAD has been called into question. This review will provide information that revascularization exerts favourable effects on symptoms, quality of life, exercise capacity, and survival, particularly in those with extensive CAD and documented moderate-to-severe ischaemia. Accordingly, CABG and PCI should be considered a valuable adjunct rather than an alternative to medical therapy.

Adverse effects of drugs on the esophagus

Given the function of the esophagus to transport orally ingested solids and liquids into the stomach there are several medications with adverse effect on esophageal structures and function. Various pharmacologic agents can induce esophageal injury, promote gastroesophageal reflux by decreasing lower esophageal sphincter tone or affect esophageal perception and motility. The risks of bisphosphonates, doxycycline, ferrous sulfate, ascorbic acid, aspirin/NSAIDs and chemotherapeutic agents to induce esophageal lesions have been documented in case reports and short series. In addition to direct mucosal injury, many commonly used medications including nitroglycerins, anticholinergics, beta-adrenergic agonists, aminophyllines, and benzodiazepines promote/facilitate gastroesophageal reflux by reducing lower esophageal sphincter pressure. Additional evidence accumulates on the adverse effects of various medications on esophageal motility and perception. The treatment of medication-induced esophageal lesions includes (1) identifying and discontinuing the causative medication, (2) promoting healing of esophageal injury by decreasing esophageal acid exposure or coating already existing esophageal lesions, (3) eventual use of protective compounds.

T-cell recognition of chemicals, protein allergens and drugs: towards the development of in vitro assays

Chemicals can elicit T-cell-mediated diseases such as allergic contact dermatitis and adverse drug reactions. Therefore, testing of chemicals, drugs and protein allergens for hazard identification and risk assessment is essential in regulatory toxicology. The seventh amendment of the EU Cosmetics Directive now prohibits the testing of cosmetic ingredients in mice, guinea pigs and other animal species to assess their sensitizing potential. In addition, the EU Chemicals Directive REACh requires the retesting of more than 30,000 chemicals for different toxicological endpoints, including sensitization, requiring vast numbers of animals. Therefore, alternative methods are urgently needed to eventually replace animal testing. Here, we summarize the outcome of an expert meeting in Rome on 7 November 2009 on the development of T-cell-based in vitro assays as tools in immunotoxicology to identify hazardous chemicals and drugs. In addition, we provide an overview of the development of the field over the last two decades.

Development of an LC-MS/MS method for the quantitation of 55 compounds prescribed in combined cardiovascular therapy

This paper reports an LC-MS/MS method with positive electrospray ionization for the screening of commonly prescribed cardiovascular drugs in human plasma, including compounds with antihypertensive (57), antidiabetic (12), hypolipemiant (5), anticoagulant (2) and platelet anti-aggregation (2) effects. Sample treatment consisted of a simple protein precipitation with MeOH/0.1 M ZnSO₄ (4:1, v/v) solution after the addition of internal standard, followed by evaporation and reconstitution. Analytes separation was performed on a Polar-RP column (150 m x 2 mm, 4 μm) using a gradient elution of 15 min. The MS system was operated in MRM mode, monitoring one quantitation and one confirmation transition for each analyte. The recovery of the protein precipitation step ranged from 50 to 70% for most of the compounds, while some were considerably affected by matrix effects. Since several analytes fulfilled the linearity, accuracy and precision values required by the ICH guidelines, the method proved to be suitable for their quantitative analysis. The limits of quantitation varied from 0.38 to 9.1 μg/L and the limits of detection from 0.12 to 5.34 μg/L. The method showed to be suitable for the detection of plasma samples of patients under cardiovascular treatment with the studied drugs, and for 55 compounds reliable quantitative results could be obtained.

Bioanalysis of new designer drugs

Since the late 1990s the illicit drug market has undergone considerable change: along with the traditional drugs of abuse that still dominate, more than 100 psychotropic substances designed to bypass controlled substances legislation have appeared and led to intoxications and fatalities. Starting from the huge class of phenylalkylamines, containing many subgroups, the spectrum of structures has grown from tryptamines, piperazines, phenylcyclohexyl derivates and pyrrolidinophenones to synthetic cannabinoids and the first synthetic cocaine. Due to the small prevalence and high number of unknown substances, the detection of new designer drugs is a challenge for clinical and forensic toxicologists. Standard screening procedures might fail because a recently discovered or yet unknown substance has not been incorporated in the library used. Nevertheless, many metabolism studies, case reports, screening methods and substance-profiling papers concentrating on single compounds have been published. This review provides an overview of the developed bioanalytical and analytical methods, the matrices used, sample-preparation procedures, concentration of analytes in case of intoxication and also gives a résumé of immunoassay experiences. Additionally, six screening methods for biological matrices with a larger spectrum of analytes are described in more detail.

Detection and identification of 700 drugs by multi-target screening with a 3200 Q TRAP LC-MS/MS system and library searching

The multi-target screening method described in this work allows the simultaneous detection and identification of 700 drugs and metabolites in biological fluids using a hybrid triple-quadrupole linear ion trap mass spectrometer in a single analytical run. After standardization of the method, the retention times of 700 compounds were determined and transitions for each compound were selected by a "scheduled" survey MRM scan, followed by an information-dependent acquisition using the sensitive enhanced product ion scan of a Q TRAP hybrid instrument. The identification of the compounds in the samples analyzed was accomplished by searching the tandem mass spectrometry (MS/MS) spectra against the library we developed, which contains electrospray ionization-MS/MS spectra of over 1,250 compounds. The multi-target screening method together with the library was included in a software program for routine screening and quantitation to achieve automated acquisition and library searching. With the help of this software application, the time for evaluation and interpretation of the results could be drastically reduced. This new multi-target screening method has been successfully applied for the analysis of postmortem and traffic offense samples as well as proficiency testing, and complements screening with immunoassays, gas chromatography-mass spectrometry, and liquid chromatography-diode-array detection. Other possible applications are analysis in clinical toxicology (for intoxication cases), in psychiatry (antidepressants and other psychoactive drugs), and in forensic toxicology (drugs and driving, workplace drug testing, oral fluid analysis, drug-facilitated sexual assault).