The safety of clopidogrel

Efficacy, Safety, and Role of Antiplatelet Drugs in the Management of Acute Coronary Syndrome: A Comprehensive Review of Literature

Acute coronary syndrome (ACS) is a complex condition characterized by myocardial ischemia or infarction which can lead to significant morbidity and death. Antiplatelet drugs play a crucial role in the management of ACS and have been shown to minimize the incidence of significant adverse cardiovascular events and recurrent myocardial infarction (MI). This comprehensive literature review is intended to summarize current information on the effectiveness, safety, and function of frequently used antiplatelet medications in treating ACS. Aspirin, clopidogrel, prasugrel, ticagrelor, abciximab, tirofiban, dipyridamole, cilostazol, and novel antiplatelets are included in the review. Aspirin's effectiveness as a first-line antiplatelet medication in ACS is well established. It has significantly lowered the risk of serious adverse cardiovascular events. Clopidogrel, prasugrel, and ticagrelor are P2Y12 receptor inhibitors found to lower the incidence of recurrent ischemia episodes in ACS patients. Using glycoprotein IIb/IIIa inhibitors such as abciximab, tirofiban, and eptifibatide is effective in managing ACS, especially in high-risk patients. Dipyridamole effectively reduces the risk of recurrent ischemic events in patients with ACS, particularly when used with aspirin. Cilostazol, a phosphodiesterase III inhibitor, has also been shown to reduce the risk of major adverse cardiovascular events (MACE) in patients with ACS. Antiplatelet drugs' safety in managing ACS has also been well established. Aspirin is generally well-tolerated with a low risk of adverse effects, although the risk of bleeding events, particularly gastrointestinal bleeding, cannot be eliminated. The P2Y12 receptor inhibitors have been associated with a small increase in the risk of bleeding events, particularly in patients with a high risk of bleeding. The glycoprotein IIb/IIIa inhibitors are associated with a higher risk of bleeding than other antiplatelet drugs, especially in high-risk patients. To summarize, antiplatelet drugs play a crucial role in the management of ACS, and the efficacy and safety of these drugs have been well-established in the literature. The choice of antiplatelet drugs will depend on the patient's risk factors, including age, comorbidities, and bleeding risk. The novel antiplatelets may offer new therapeutic options for managing ACS, and further studies are needed to determine their role in managing this complex condition.

The pharmacological treatment of acute vestibular syndrome

Acute vestibular syndrome (AVS) represents a clinical picture that involves urgent management due to the important procession of symptoms accompanying the event, which can be positively or negatively influenced by therapeutic choices and intervention timing. This forces a differential diagnosis and therapeutic choices to be made in conditions that are not always favorable and often not in the specialist field. In this work, we will examine in detail the pharmacological therapeutic possibilities, correlating them to the differential and, as far as possible, to the etiological diagnosis. In particular, the pharmacological possibilities for the two main conditions we can face will be investigated, namely, vestibular neuritis and posterior circulation stroke.

The Improvement of Cardiac and Endothelial Functions of Xue-Fu-Zhu-Yu Decoction for Patients with Acute Coronary Syndrome: A Meta-Analysis of Randomized Controlled Trials

Background

Xue-Fu-Zhu-Yu decoction (XFZYD) is a traditional Chinese prescription that has been used to treat patients with blood stasis in China for many years. The present study aimed to evaluate the improvement of cardiac and endothelial functions of XFZYD for patients with acute coronary syndrome (ACS) through a systematic review and meta-analysis.

Methods

Six databases were searched to collect RCTs related to the treatment of XFZYD for ACS. The primary outcomes were cardiac and endothelial functions, including the levels of left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), and left ventricular end-systolic diameter (LVESD) in echocardiography, as well as the changes in the levels of nitric oxide (NO), endothelin-1 (ET-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in the serum. The secondary outcomes were the blood levels of oxidative damage markers (including superoxide dismutase (SOD) and malondialdehyde (MDA)), C-reactive protein (CRP), brain natriuretic peptide (BNP), creatine kinase-MB (CK-MB), and cardiac troponin I (cTnI) as well as the incidence of adverse drug reactions (ADRs). Weighted mean difference (WMD) was estimated for all the outcomes with the random effects model. This type of analysis was conducted in the subgroups of the ACS subtypes, and the methodological quality was assessed using the handbook of Cochrane Collaboration.

Results

A total of 1,658 records were identified, and 16 randomized controlled trials (1,171 patients) were included. The primary outcomes suggested that XFZYD combined with routine treatment improved LVEF, reduced LVEDD and LVESD, and also improved the serum levels of NO, and reduced the levels of ET-1 and ICAM-1. XFZYD combination therapy significantly ameliorated the blood levels of SOD, MDA, BNP, CK-MB, and cTnI. However, the results indicated no significant difference between XFZYD plus routine treatment and routine treatment for the levels of VCAM-1 and CRP. Moreover, all the ADRs reported in the included studies were slight and the patients recovered soon.

Conclusions

The present study suggested that XFZYD may improve the cardiac and endothelial functions of ACS patients without serious ADRs. However, based on the mediocre methodological quality, the aforementioned conclusion should be confirmed in a multicenter, large-scale, and accurately designed clinical trial.

Preparation of injectable clopidogrel loaded submicron emulsion for enhancing physicochemical stability and anti-thrombotic efficacy

Due to the superior safety and therapeutic efficacy, clopidogrel (CLP) has been widely used to prevent postoperative thrombosis. However, limitations of delayed absorption and metabolic activation of clopidogrel after oral administration hinder its clinic use for acute thrombosis treatment in percutaneous coronary intervention (PCI). Although clopidogrel aqueous injection systems were designed and developed, chemical instability under physiological condition or vascular irritation remains to be solved. In this study, we aim to prepare an injectable clopidogrel loaded submicron emulsion to overcome the drawbacks of conventional clopidogrel aqueous formulation and improve the antiplatelet aggregation effects. Results showed that this delivery system exerted inspiring features including uniform particle size, higher drug loading capacity and sustained drug release behavior. It can dramatically upgrade the formulation stability and prevent the drug degradation under sterilization or higher pH environments. No remarkable droplet size increase or drug content decrease was observed during storage. Compared to CLP tablet, the peak drug concentration (C_max) and area under the curve (AUC) of CLP emulsion increased by 12.01-fold and 4.69-fold, respectively. Most importantly, it exerted excellent in vivo anti-thrombotic effect on numerous designed animal models. Conclusively, submicron emulsion is a promising delivery system for improving clopidogrel stability and anti-thrombotic efficacy.

Effect of Spray Drying Conditions on Physical Properties of Panax notoginseng Saponin (PNS) Powder and the Intra-Batch Dissolution Variability of PNS Hydrophilic Matrix Tablet

Purpose

Understanding raw material variability and its impact on product quality are crucial for developing robust pharmaceutical processes. This work aimed to study the effects of spray drying conditions on properties of the spray dried Panax notoginseng saponin (PNS) powders as well as the subsequent intra-batch dissolution variability of PNS hydrophilic matrix tablets.

Methods

The Plackett-Burman design was applied to screen the critical process parameters (CPPs). Then, the Box-Behnken design was used to investigate the relationship between the CPPs and the physiochemical properties of spray dried PNS powders. The PNS hydrophilic matrix tablets containing 57% spray dried PNS powders were directly compressed. The partial least squares (PLS) regression was used to uncover the hidden multivariate relationships among the CPPs, intermediate powder properties, and tablet quality attributes.

Results

The identified CPPs were the feed concentration, the inlet air temperature, and the atomization pressure. It was found that the CPPs exerted little impact on chemical properties of spray dried PNS powders, but had significant impact on physical properties, such as particle size, specific surface area, bulk density, hygroscopicity, and inter-particle porosity, etc. Latent variable modeling results revealed that the high inlet air temperature of spray drying process could produce PNS powders with low moisture content and high hygroscopicity, which were beneficial to reduce the intra-batch dissolution variability of PNS hydrophilic matrix tablets. Finally, a design space of the spray drying process was built in order to ensure the dissolution consistency.

Conclusion

Our research provided a reference for improving the spray drying conditions in order to ensure the dissolution consistency of the PNS hydrophilic matrix tablet.

Increased Risk of Clopidogrel-Induced Gastric Mucosal Erosion in Elderly Chinese Men Harboring the ABCB1 3435T Allele

Background

It is uncertain whether long-term use of clopidogrel alone can cause gastric mucosal injury. This study aimed to evaluate the relationship between ABCB1 C3435T polymorphisms, which could affect the intestinal absorption of clopidogrel, and gastric mucosal erosion in elderly Chinese men who used clopidogrel alone.

Methods

We selected 298 male patients (aged between 68.2 and 89.5 years, average age 78); 201 of them constituted the control group, and 97 constituted the case group. Patients taking clopidogrel alone who had undergone endoscopic screening for gastric erosion were analyzed for ABCB1 C3435T polymorphisms by a TaqMan assay.

Results

The proportion of people carrying the ABCB1 3435T allele (n = 63, 64.9% vs n = 97, 48.3%, p = 0.007) was significantly higher in the case group than in the control group. After adjustments for significant factors were made, ABCB1 3435T allele carrier (OR 2.14, 95% CI 1.43–3.84, p <0.01) was found to be associated with gastric mucosal erosion in people who used clopidogrel alone.

Conclusion

Carrying the ABCB1 3435T allele may be a useful genetic predictor for clopidogrel-induced gastric mucosal erosion in elderly Chinese men.

Progress in interventional cardiology: challenges for the future

Cardiovascular disease is the leading cause of death in the western and developing countries. Percutaneous transluminal coronary interventions have become the most prevalent treatment option for coronary artery disease; however, due to serious complications, such as stent thrombosis and in-stent restenosis (ISR), the efficacy and safety of the procedure remain important issues to address. Strategies to overcome these aspects are under extensive investigation. In this review, we summarise relevant milestones during the time to overcome these limitations of coronary stents, such as the development of polymer-free drug-eluting stents (DES) to avoid pro-inflammatory response due to the polymer coating or the developement of stents with cell-directing drugs to, simultaneously, improve re-endothelialisation and inhibit ISR amongst other techniques most recently developed, which have not fully entered the clinical stage. Also the novel concept of fully biodegradable DES featured by the lack of a permanent foreign body promises to be a beneficial and applicable tool to restore a natural vessel with maintained vasomotion and to enable optional subsequent surgical revascularisation.

Complication rate of ultrasound-guided percutaneous cholecystostomy in patients with coagulopathy

OBJECTIVE

The purpose of this article is to compare the complication rate for ultrasound-guided percutaneous cholecystostomy in patients with coagulopathy to the rate in patients with normal coagulation.

MATERIALS AND METHODS

We performed a database search for patients who underwent ultrasound-guided percutaneous cholecystostomy from January 2000 through December 2010. Patients were divided into those with normal coagulation and those with coagulopathy, as documented by abnormal laboratory values (international normalized ratio ≥ 1.5 and platelet count ≤ 50 × 10(9)/L) or history of anticoagulant medication in the preceding 5 days. Medical records were reviewed, and complication rates and subsequent treatment was recorded. Statistical analysis was performed using the Fisher exact and chi-square tests.

RESULTS

Two hundred forty-two patients underwent ultrasound-guided percutaneous cholecystostomy (132 men and 110 women; mean [± SD] age, 73.9 ± 15.9 years; range, 22-104 years). One hundred thirty-two patients were coagulopathic and 110 had normal coagulation. Major complications related to ultrasound-guided percutaneous cholecystostomy were rare (4/242 cases [1.7%]) and included hemorrhage requiring transfusion (n = 1), death directly related to the procedure (n = 1), sepsis related to the procedure (n = 1), and abscess or biloma formation (n = 1). All of these occurred in the group with normal coagulation. Fourteen additional deaths (5.8%) that occurred within 30 days of the procedure were related to comorbidities. Minor catheter-related complications (15/242 [6.2%]) were due to catheter dislodgement (n = 11 [4.5%]), failure of placement (n = 1 [0.4%]), and hemorrhage not requiring transfusion (n = 3 [1.2%]). Two of the minor hemorrhagic complications were seen in the coagulopathic group and one in the normal coagulation group (p = 0.599).

CONCLUSION

There is no difference in the complication rate for ultrasound-guided percutaneous cholecystostomy in patients who are coagulopathic compared with those who have normal coagulation.

Off-Target Platelet Activation in Macaques Unique to a Therapeutic Monoclonal Antibody

AMG X, a human neutralizing monoclonal antibody (mAb) against a soluble human protein, caused thrombocytopenia, platelet activation, reduced mean arterial pressure, and transient loss of consciousness in cynomolgus monkeys after first intravenous administration. In vitro, AMG X induced activation in platelets from macaque species but not from humans or baboons. Other similar mAbs against the same pharmacological target failed to induce these in vivo and in vitro effects. In addition, the target protein was known to not be expressed on platelets, suggesting that platelet activation occurred through an off-target mechanism. AMG X bound directly to cynomolgus platelets and required both the Fab and Fc portion of the mAb for platelet activation. Binding to platelets was inhibited by preincubation of AMG X with its pharmacological target or with anti-human Fc antibodies or by preincubation of platelets with AMG X F(ab′)2 or human immunoglobulin (IVIG). AMG X F(ab′)2 did not activate platelets. Thus, platelet activation required both recognition/binding of a platelet ligand with the Fab domain and interaction of platelet Fc receptors (i.e., FcγRIIa) with the Fc domain. These findings reflect the complexity of the mechanism of action of mAbs and the increasing awareness of potential for unintended effects in preclinical species.