Current dosing of low-molecular-weight heparins does not reflect licensed product labels: an international survey

Meta-analysis of Different Pressing Time on the Incidence of Subcutaneous Hemorrhage of Low Molecular Weight Heparin Administration

To investigate the effect of different pressing time on the incidence of subcutaneous hemorrhage of low molecular weight heparin (LMWH) administration by meta-analysis. Cochrane Library, PubMed, MEDLINE, CINAHL, EMbase, Springer, EBSCO, China Biomedical Literature Database, CNKI, Wanfang Database, and VIP Database were searched. To screen the literature of randomized controlled trials with different pressing time in patients with subcutaneous LMWH injection from the establishment of the database to December 2020. The quality of the literature was evaluated and the data were extracted. Meta-analysis was performed by RevMan 5.3. A total of 17 randomized controlled trials were included. Meta-analysis showed that the bleeding rate of pressing for 5 min odds ratio (OR  =  3.89, 95% confidence interval [CI]: 2.68-5.64, P < .05) or pressing for 10 min (OR  =  1.99, 95% CI: 1.34-2.95) was significantly lower than that of pressing for 3 min. Moreover, the bleeding rate was significantly lower in the 5 min pressing (OR  =  1.47, 95% CI: 1.18-1.82) and 10 min pressing(OR  =  2.12, 95% CI: 1.61-2.77) than in the no compression group. It is the most suitable time to press 5 min after subcutaneous LMWH injection, which can better control the incidence of bleeding.

Pharmacological and clinical application of heparin progress: An essential drug for modern medicine

Heparin is the earliest and most widely used anticoagulant and antithrombotic drug that is still used in a variety of clinical indications. Since it was discovered in 1916, after more than a century of repeated exploration, heparin has not been replaced by other drugs, but a great progress has been made in its basic research and clinical application. Besides anticoagulant and antithrombotic effects, heparin also has antitumor, anti-inflammatory, antiviral, and other pharmacological activities. It is widely used clinically in cardiovascular and cerebrovascular diseases, lung diseases, kidney diseases, cancer, etc., as the first anticoagulant medicine in COVID-19 exerts anticoagulant, anti-inflammatory and antiviral effects. At the same time, however, it also leads to a lot of adverse reactions, such as bleeding, thrombocytopenia, elevated transaminase, allergic reactions, and others. This article comprehensively reviews the modern research progress of heparin compounds; discusses the structure, preparation, and adverse reactions of heparin; emphasizes the pharmacological activity and clinical application of heparin; reveals the possible mechanism of the therapeutic effect of heparin in related clinical applications; provides evidence support for the clinical application of heparin; and hints on the significance of exploring the wider application fields of heparin.

Therapeutic Enoxaparin in the Morbidly Obese Patient: A Case Report and Review of the Literature

Enoxaparin is a low molecular weight heparin commonly used in the treatment of venous thromboembolisms (VTEs); however, evidence on optimal empiric dosing recommendations are lacking in patients with morbid obesity. Utilization of an absolute dose cap, anti-Xa monitoring, and reduced empiric dosing are among the techniques used in this population. We describe a case of a morbidly obese man (body-mass index, BMI: 68.2 kg/m², total body weight: 236 kg) who required therapeutic enoxaparin for suspected pulmonary embolism (PE) and critical limb ischemia as a bridge therapy during warfarin initiation. An initial empiric dose of 200 mg Q12 hours (0.85 mg/kg) resulted in an anti-Xa level of 1.01 IU/mL following the fifth dose, and no dose modification was deemed necessary. He experienced no adverse effects from treatment. This report adds to a growing body of evidence illustrating the need for reduced empiric weight-based doses of enoxaparin in the morbidly obese population and raises the question of whether dose capping is an appropriate practice in the clinical setting of morbidly obese patients with acute VTE.

Comparison of modified versus conventional injection techniques of low-molecular-weight heparin in elderly

Objective:

To analyze the clinical values of modified injection of low-molecular-weight heparin in reducing subcutaneous bleeding and pain.

Methods:

Two hundred and sixty patients with cerebral infarction, acute myocardial infarction or pulmonary embolism who underwent subcutaneous injection of low-molecular weight heparin in the hospital between December 2015 and December 2016 were selected. They were randomly divided into a control group and a research group, 130 each. Patients in the control group were given conventional injection, while patients in the research group were given modified injection. The occurrence of subcutaneous bleeding and pain was observed and compared between the two groups.

Results:

The incidence of subcutaneous hemorrhage in the research group was 46.9%, significantly lower than 83.1% in the control group, and the difference had statistical significance (P<0.05). Twenty-six patients in the control group had severe pain, which was much more than 5 patients in the research group, and the difference was statistically significant (P<0.05). The number of cases of severe hemorrhage in the control group was significantly larger than that of the research group (31 vs. 3), and the difference was also statistically significant.

Conclusion:

Modified low-molecular weight heparin injection can effectively reduce the incidence of bleeding and pain, which is beneficial to the compliance and quality of life of elder patients.

The use of mechanistic evidence in drug approval

The role of mechanistic evidence tends to be under-appreciated in current evidence-based medicine (EBM), which focusses on clinical studies, tending to restrict attention to randomized controlled studies (RCTs) when they are available. The EBM+ programme seeks to redress this imbalance, by suggesting methods for evaluating mechanistic studies alongside clinical studies. Drug approval is a problematic case for the view that mechanistic evidence should be taken into account, because RCTs are almost always available. Nevertheless, we argue that mechanistic evidence is central to all the key tasks in the drug approval process: in drug discovery and development; assessing pharmaceutical quality; devising dosage regimens; assessing efficacy, harms, external validity, and cost-effectiveness; evaluating adherence; and extending product licences. We recommend that, when preparing for meetings in which any aspect of drug approval is to be discussed, mechanistic evidence should be systematically analysed and presented to the committee members alongside analyses of clinical studies.

Dosing of Enoxaparin in Morbidly Obese Patients: A Retrospective Cohort

Purpose: The purpose of this study was to evaluate odds of major bleeding, thrombosis, and ischemic stroke between different enoxaparin dosage strategies in patients weighing ≥120 kg. Methods: Patients weighing ≥120 kg who received therapeutic anticoagulation with enoxaparin for more than 24 hours were selected for retrospective review. Patients without a baseline weight, serum creatinine, a history of heparin-induced thrombocytopenia, or currently pregnant patients were excluded from the study. Patients with a creatinine clearance (CrCL) <30 mL/min were analyzed separately. The incidence of major bleeding was compared between patients receiving <90% and those receiving ≥90% of the Food and Drug Administration (FDA)-approved dose of enoxaparin, as well as between patients weighing ≥150 kg and those weighing <150 kg. Secondary outcomes included incidence of venous thromboembolism (VTE) and ischemic stroke. Results: A total of 462 patients were included in the primary analysis and 25 patients in the subgroup analysis. No difference in major bleeding was observed between different dosage regimens (P = .12) or weight groups (P = .36). No difference was observed in rates of VTE or ischemic stroke between different dosage regimens (P = .52 and P = .60, respectively) or weight groups (P = .39 and P = .48, respectively). Similar results were observed in the low-CrCL analysis. Results were not altered when patients were propensity matched on baseline characteristics. Conclusion: Reducing the dose of enoxaparin did not reduce the odds of major bleeding or increase the odds of ischemic stroke or VTE.

Reduced dosing of enoxaparin for venous thromboembolism in overweight and obese adolescents: a single institution retrospective review

BACKGROUND

The global obesity epidemic has created new challenges, including venous thromboembolisms (VTE) in obese adolescents. The data on whether to reduce the dose of low-molecular heparin in obese adults is conflicting, and information on adolescent patients is scarce.

OBJECTIVES

Our primary goal was to describe dosing, anti-Xa levels, and outcomes of overweight and obese adolescents who received reduced doses of enoxaparin at the initiation of therapy. The secondary goal was to compare their outcomes to overweight and obese adolescents who received standard 1 mg/kg dosing to determine if future trials for dose reduction are warranted.

PATIENTS/METHODS

We performed a retrospective cohort study of overweight and obese patients between the ages of 12 and 18 years old diagnosed with VTE who were treated with reduced dosing (RD) of enoxaparin, comparing their dosing, anti-Xa levels, and outcomes to overweight and obese adolescents who received standard dosing (SD).

RESULTS

RD patients (n=19) achieved therapeutic mean initial anti-Xa levels that were similar to SD patients (n=11). Of the RD patients, 53% did not require dose adjustments during treatment. Two RD patients had thrombus progression. A total of 25 patients ultimately completed therapy with RD.

CONCLUSIONS

Future trials are warranted to evaluate the efficacy and safety of reduced dosing of enoxaparin to treat overweight and obese adolescents with VTE.

Evaluation and Pharmacokinetics of Treatment Dose Enoxaparin in Hospitalized Patients With Morbid Obesity

Background:

The pharmacokinetic properties of enoxaparin may lead to supratherapeutic antifactor Xa (anti-Xa) levels and increased bleeding when standard treatment doses are used in patients with morbid obesity.

Objective:

To evaluate the dose of enoxaparin needed to achieve therapeutic anti-Xa levels in a prospective, masked observational cohort of heterogeneous inpatients with morbid obesity and to determine whether patients with morbid obesity treated with 1 mg/kg of enoxaparin are at increased risk of supratherapeutic levels and bleeding events compared to patients receiving lower doses.

Methods:

Hospitalized patients with a body mass index ≥40 kg/m2 or actual body weight ≥140 kg and prescribed treatment doses of enoxaparin >60 mg per day were enrolled and consented to phlebotomy for determination of anti-Xa levels.

Results:

Forty-one patients were included for data analysis. The dose of enoxaparin that resulted in therapeutic and supratherapeutic anti-Xa levels at steady state was 0.83 mg/kg and 0.98 mg/kg (−0.11; 95% confidence interval [CI] −0.20 to −0.01, P = .02), respectively. Enoxaparin dose as mg/kg of actual body weight was an independent predictor of having a supratherapeutic anti-Xa level. Patients with doses <0.95 mg/kg versus ≥0.95 mg/kg were less likely to have supratherapeutic levels (odds ratio 0.21 [95% CI 0.05-0.84], P = .02) and had similar rates of subtherapeutic levels. Doses <0.95 mg/kg and ≥0.95 mg/kg resulted in similar bleeding rates of 17.9% and 22.2% ( P = .71), respectively.

Conclusion:

Patients with morbid obesity required less than the recommended 1 mg/kg enoxaparin dose to achieve therapeutic peak anti-Xa levels; therefore, initiation with lower dosages is prudent and anti-Xa monitoring should guide dosage adjustments.

Automating and estimating glomerular filtration rate for dosing medications and staging chronic kidney disease

Objective

The purpose of this paper is to serve as a review for primary care providers on the bedside methods for estimating glomerular filtration rate (GFR) for dosing and chronic kidney disease (CKD) staging and to discuss how automated health information technologies (HIT) can enhance clinical documentation of staging and reduce medication errors in patients with CKD.

Methods

A nonsystematic search of PubMed (through March 2013) was conducted to determine the optimal approach to estimate GFR for dosing and CKD staging and to identify examples of how automated HITs can improve health outcomes in patients with CKD. Papers known to the authors were included, as were scientific statements. Articles were chosen based on the judgment of the authors.

Results

Drug-dosing decisions should be based on the method used in the published studies and package labeling that have been determined to be safe, which is most often the Cockcroft–Gault formula unadjusted for body weight. Although Modification of Diet in Renal Disease is more commonly used in practice for staging, the CKD–Epidemiology Collaboration (CKD–EPI) equation is the most accurate formula for estimating the CKD staging, especially at higher GFR values. Automated HITs offer a solution to the complexity of determining which equation to use for a given clinical scenario. HITs can educate providers on which formula to use and how to apply the formula in a given clinical situation, ultimately improving appropriate medication and medical management in CKD patients.

Conclusion

Appropriate estimation of GFR is key to optimal health outcomes. HITs assist clinicians in both choosing the most appropriate GFR estimation formula and in applying the results of the GFR estimation in practice. Key limitations of the recommendations in this paper are the available evidence. Further studies are needed to better understand the best method for estimating GFR.

Dosing of medications in morbidly obese patients in the intensive care unit setting

OBJECTIVE

To derive recommendations for the dosing of commonly used medications in the morbidly obese patient in the ICU.

DATA SOURCES

Articles were obtained through computerized searches involving MEDLINE. The bibliographies of retrieved publications and textbooks were reviewed for additional references.

STUDY SELECTION

All studies involving the pharmacokinetics or pharmacodynamics of medications in obese subjects or patients.

DATA EXTRACTION

The emphasis was on studies involving morbidly obese patients but, in the absence of such data, investigations involving lesser forms of obesity were extracted.

DATA SYNTHESIS

There is a paucity of data upon which to make recommendations for dosing commonly used medications in the morbidly obese patient in the ICU, although recommendations were provided based on the available information.

CONCLUSIONS

There is clearly a need for more investigations involving dosing regimens of medications in the morbidly obese population. Until such studies are available, the clinician must try to derive the best dosing regimens for medications based on the limited pharmacokinetic data available for some agents and clinical judgement.