Enoxaparin: a pharmacoeconomic review of its use in the prevention and treatment of venous thromboembolism and in acute coronary syndromes

Standard Fixed Enoxaparin Dosing for Venous Thromboembolism Prophylaxis Leads to Low Peak Anti-Factor Xa Levels in Both Head and Neck and Breast Free Flap Patients

INTRODUCTION

 Venous thromboembolism (VTE) is a serious complication, particularly in cancer patients undergoing free flap reconstruction. Subcutaneous enoxaparin is the conventional prophylaxis for VTE prevention, and serum anti-factor Xa (afXa) levels are being increasingly used to monitor enoxaparin activity. In this study, free flap patients receiving standard enoxaparin prophylaxis were prospectively followed to investigate postoperative afXa levels and 90-day VTE and bleeding-related complications.

METHODS

 Patients undergoing free tissue transfer during an 8-month period were identified and prospectively followed. Patients received standard fixed enoxaparin dosing at 30 mg twice daily in head and neck (H&N) and 40 mg daily in breast reconstructions. Target peak prophylactic afXa range was 0.2 to 0.5 IU/mL. The primary outcome was the occurrence of 90-day postoperative VTE- and bleeding-related events. Independent predictors of afXa level and VTE incidence were analyzed for patients that met the inclusion criteria.

RESULTS

 Seventy-eight patients were prospectively followed. Four (5.1%) were diagnosed with VTE, and six (7.7%) experienced bleeding-related complications. The mean afXa levels in both VTE patients and bleeding patients were subprophylactic (0.13 ± 0.09 and 0.11 ± 0.07 IU/mL, respectively). Forty-six patients (21 breast, 25 H&N) had valid postoperative peak steady-state afXa levels. Among these, 15 (33%) patients achieved the target prophylactic range: 5 (33%) H&N and 10 (67%) breast patients. The mean afXa level for H&N patients was significantly lower than for breast patients (p = 0.0021). Patient total body weight was the sole negative predictor of afXa level (R ² = 0.47, p < 0.0001).

CONCLUSION

 Standard fixed enoxaparin dosing for postoperative VTE prophylaxis does not achieve target afXa levels for the majority of our free flap patients. H&N patients appear to be a particularly high-risk group that may require a more personalized and aggressive approach. Total body weight is the sole negative predictor of afXa level, supporting a role for weight-based enoxaparin dosing.

The Effect of Extended Injection of Subcutaneous Heparin on Pain Intensity and Bruising Incidence

Background

Reducing patients’ pain is one of the main goals of providing clinical services, which requires nursing skill. As a simple technique, increasing the duration of subcutaneous heparin injection may affect the intensity of pain and bruising.

Objective

The aim of this study was to assess the effect of increasing the heparin injection time on pain intensity and bruising associated with subcutaneous injection.

Methods

The present quasi-experimental study consisted of 86 patients, admitted to our hospital, who were treated with subcutaneous heparin injection. A McGill pain intensity questionnaire was used to measure pain severity in a purposive sampling. All of the subjects received subcutaneous heparin twice for 10 seconds. They also were injected twice with heparin infusion, although it was for 30 seconds this time. The interval between the two injections was 24 h, and the intensity of the pain was measured after each injection. The Pearson correlation coefficient was measured, and analysis of variance (ANOVA) and the t-test were used to analyze the data.

Results

Eighty patients received heparin. The body mass indexes were reported as 52 (60%) and 34 (40%) for subjects within the age range of 18.5–24.9 and 25–29.9, respectively. Regarding the mean of pain intensity, there was a significant difference between the 10 and 30 s injections (p < 0.05). Additionally, there was a significant difference in bruising rates between the two methods 48 and 72 h after injection (p < 0.05). The ANOVA test showed a significant association between gender and bruising (p = 0.001).

Conclusion

According to the results, by elevating the duration of heparin injection, the severity of pain was reduced, and, therefore, the patients felt more comfortable.

Trial Registration

The trial was registered at the Thai Clinical Trials Registry (TCTR) with the TCTR identification of TCTR20160221001.

Funding

This research was supported by the research cluster grant (88186-25/01/89) from Mashhad University of Medical Sciences, Mashhad, Iran. The authors received no financial support for the authorship and/or publication of this article.

Thromboprophylaxis for lung cancer patients--multimodality assessment of clinician practices, perceptions and decision support tools

PURPOSE

The purpose of this study was to report the opinions and self-reported practices of clinicians, as well as the availability of decision support tools, regarding appropriate thromboprophylaxis for patients with lung cancer to identify variation in practice and/or divergence from evidence-based clinical practice guidelines (CPG).

METHODS

A computer-generated survey (SurveyMonkey software) was distributed to surgical, radiation and medical oncologists with lung cancer specialisation, via membership of the Australian Lung Cancer Trials Group (ALTG) from May to September 2013.

RESULTS

Seventy-two clinicians, from public, private, specialist and general hospitals, completed the survey (46% response rate). Hospital-endorsed CPG were widely available (91%); however, these routinely lacked robust recommendations for the ambulatory care setting (98%) and risk stratification tools (65%). Clinicians consistently identified ambulatory care treatment modalities (chemotherapy, alone or in combination with radiotherapy) as having similar (high) thrombotic risk as surgery. Timing and duration of pharmacological thromboprophylaxis prescribing among surgical oncologists varied and were divergent from guideline recommendations. Fifty-eight percent of surveyed clinicians cited a lack of high-quality data to guide preventative strategies in lung cancer patients.

CONCLUSION

Clinicians consistently identified patients with lung cancer as having a high thromboembolic risk in both ambulatory and surgical settings, but with differences in recommendations and variation in practice. CPG lacked robust recommendations for the ambulatory care setting, the main arena for the multimodality lung cancer treatment paradigm.

Cost-effectiveness impact of rivaroxaban versus new and existing prophylaxis for the prevention of venous thromboembolism after total hip or knee replacement surgery in France, Italy and Spain

Venous thromboembolism (VTE) has a significant impact on healthcare costs but is largely preventable with anticoagulant prophylaxis using low-molecular-weight heparins (LMWHs), such as enoxaparin or dalteparin. Rivaroxaban and dabigatran etexilate are two new oral anticoagulants (NOACs) both compared with enoxaparin in separate trials. A decision analytic model with a healthcare and national payer perspective over a five-year time horizon was used to evaluate the cost-effectiveness of the NOACs for VTE prophylaxis after total hip replacement (THR) or total knee replacement (TKR) in France, Italy and Spain. Efficacy and safety data were obtained from randomised controlled trials of rivaroxaban vs enoxaparin and an indirect statistical comparison for rivaroxaban vs dabigatran. Rivaroxaban demonstrated dominance across all comparisons, indications and countries. In THR, total per-patient costs were reduced by up to €160 in the enoxaparin comparison and €115 in the dabigatran comparison, respectively. In addition, quality-adjusted life-years (QALYs) were increased by up to 0.0011 and 0.0012 in each comparison, respectively. Similarly, total costs were reduced in TKR by up to €137 and €28 in the enoxaparin and dabigatran comparisons, respectively. The total number of QALYs was increased by up to 0.0014 in the enoxaparin comparison and 0.0005 in the dabigatran comparison. The results were driven by costs since the incremental benefits were minimal. Rivaroxaban use could result in substantial healthcare cost savings and improved quality of life. The results are applicable across three European countries with differing healthcare systems so, potentially, could be generalised to a much wider population.

Tissue factor, blood coagulation, and beyond: an overview

Emerging evidence shows a broad spectrum of biological functions of tissue factor (TF). TF classical role in initiating the extrinsic blood coagulation and its direct thrombotic action in close relation to cardiovascular risks have long been established. TF overexpression/hypercoagulability often observed in many clinical conditions certainly expands its role in proinflammation, diabetes, obesity, cardiovascular diseases, angiogenesis, tumor metastasis, wound repairs, embryonic development, cell adhesion/migration, innate immunity, infection, pregnancy loss, and many others. This paper broadly covers seminal observations to discuss TF pathogenic roles in relation to diverse disease development or manifestation. Biochemically, extracellular TF signaling interfaced through protease-activated receptors (PARs) elicits cellular activation and inflammatory responses. TF diverse biological roles are associated with either coagulation-dependent or noncoagulation-mediated actions. Apparently, TF hypercoagulability refuels a coagulation-inflammation-thrombosis circuit in “autocrine” or “paracrine” fashions, which triggers a wide spectrum of pathophysiology. Accordingly, TF suppression, anticoagulation, PAR blockade, or general anti-inflammation offers an array of therapeutical benefits for easing diverse pathological conditions.

Cost-effectiveness of extended prophylaxis with fondaparinux compared with low molecular weight heparin against venous thromboembolism in patients undergoing hip fracture surgery

A model was developed to estimate costs and clinical effectiveness of fondaparinux compared with enoxaparin after hip fracture surgery in Sweden. Outcomes and costs of venous thromboembolism (VTE)-related care from a health care perspective were incorporated, with symptomatic deep-vein thrombosis and pulmonary embolism, recurrent VTE, post-thrombotic syndrome, major haemorrhage and all-cause death being included. Event probabilities were derived from fondaparinux clinical trial data and published data. VTE-related resource use and associated costs as well as costs of prophylaxis were based on local Swedish data. Extended prophylaxis with fondaparinux could avoid an additional 28 symptomatic VTE per 1,000 patients compared with extended prophylaxis with enoxaparin in hip fracture surgery patients. Although the prophylaxis costs were higher in the fondaparinux group, these were offset by the lower costs associated with treating fewer VTE, which thus indicates that extended fondaparinux prophylaxis is the dominant alternative when compared with enoxaparin in hip fracture surgery.

Extended thromboprophylaxis after hip or knee replacement

Early discharge from the hospital after total joint arthroplasty has increased the need for extended outpatient thromboprophylaxis. Multiple controlled clinical trials and several meta-analyses of these data have examined various agents in different regimens. These data indicate that extended prophylaxis with a low-molecular-weight heparin after knee or hip arthroplasty significantly reduces the number of venous thromboembolic episodes with no increases in major bleeding. The data also show that > 98% of patients given long-term low-molecular-weight heparin prophylaxis remain free from symptomatic deep venous thrombosis and pulmonary embolism. Therefore, to minimize patient risk safely and cost-effectively, extended prophylaxis with low-molecular-weight heparin once-daily for 4 weeks after surgery should be considered for patients undergoing total joint arthroplasty.

Tinzaparin

Low-molecular-weight heparins (LMWH) are efficacious agents that offer clinical and pharmacoeconomic advantages over unfractionated heparin (UFH) for the treatment of ACS and venous thromboembolism. Tinzaparin is a LMWH approved for the treatment of deep venous thrombosis with and without pulmonary embolism, when used in conjunction with warfarin. In studies with hospitalized patients who had deep venous thrombosis or pulmonary embolism, tinzaparin was at least as efficacious as UFH, with fewer adverse bleeding events. It is also efficacious for thromboembolic prophylaxis in patients undergoing general and orthopedic surgery. Studies have shown that tinzaparin is at least as effective as UFH for patients undergoing surgery and in other patients at risk for developing thromboembolism. It is currently not recommended for use in patients with ischemic strokes. There are minimal data available regarding its use in the management of patients with unstable angina (UA) and non-ST-segment elevation myocardial infarction.