Home treatment of deep venous thrombosis with low molecular weight heparin: Long-term incidence of recurrent venous thromboembolism

Development and Evaluation of a Pharmacist-Driven Screening Tool to Identify Patients Presenting to the Emergency Department Who Are Eligible for Outpatient Treatment of Deep Vein Thrombosis

BACKGROUND

Deep vein thrombosis (DVT) is a critical and costly health issue. Treatment in the outpatient setting is preferred compared to the inpatient setting. However, there is a lack of evidence regarding how best to identify patients who are ideal for outpatient DVT treatment.

OBJECTIVE

To design and evaluate a pharmacist-driven screening tool for the identification of patients presenting to the emergency department (ED) at a community hospital with DVT who are appropriate for outpatient treatment.

METHODS

This study was conducted in sequential phases: compilation and vetting of screening criteria, descriptive evaluation of criteria through retrospective chart review, and quantification of potential cost savings by avoiding admissions. Criteria were collected via literature search and assembled into a screening tool, which was applied retroactively to a cohort of ED patients admitted with DVT diagnosis.

RESULTS

A screening tool was developed with multidisciplinary input and consisted of 5 categories with individual patient and disease state criteria. The majority (91%) of patients reviewed would not have qualified for outpatient DVT treatment based on the retrospective application of the screening tool. The most common disqualification criteria category was high risk of bleeding/clotting (n = 81), and the most frequently represented parameter within that category was antithrombotic therapy prior to admission (n = 53).

CONCLUSION

A screening tool may not be the most efficient method for health-care practitioners such as pharmacists to identify ED patients appropriate for outpatient management of DVT. Other avenues should be explored for improving the cost-effective management of these patients.

Home versus in-patient treatment for deep vein thrombosis

BACKGROUND

Deep vein thrombosis (DVT) occurs when a blood clot blocks blood flow through a vein, which can occur after surgery, after trauma, or when a person has been immobile for a long time. Clots can dislodge and block blood flow to the lungs (pulmonary embolism (PE)), causing death. DVT and PE are known by the term venous thromboembolism (VTE). Heparin (in the form of unfractionated heparin (UFH)) is a blood-thinning drug used during the first three to five days of DVT treatment. Low molecular weight heparins (LMWHs) allow people with DVT to receive their initial treatment at home instead of in hospital. This is an update of a review first published in 2001 and updated in 2007.

OBJECTIVES

To compare the incidence and complications of venous thromboembolism (VTE) in patients treated at home versus patients treated with standard in-patient hospital regimens. Secondary objectives included assessment of patient satisfaction and cost-effectiveness of treatment.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register (last searched 16 March 2017), the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2), and trials registries. We also checked the reference lists of relevant publications.

SELECTION CRITERIA

Randomised controlled trials (RCTs) examining home versus hospital treatment for DVT, in which DVT was clinically confirmed and was treated with LMWHs or UFH.

DATA COLLECTION AND ANALYSIS

One review author selected material for inclusion, and another reviewed the selection of trials. Two review authors independently extracted data and assessed included studies for risk of bias. Primary outcomes included combined VTE events (PE and recurrent DVT), gangrene, heparin complications, and death. Secondary outcomes were patient satisfaction and cost implications. We performed meta-analysis using fixed-effect models with risk ratios (RRs) and 95% confidence intervals (CIs) for dichotomous data.

MAIN RESULTS

We included in this review seven RCTs involving 1839 randomised participants with comparable treatment arms. All seven had fundamental problems including high exclusion rates, partial hospital treatment of many in the home treatment arms, and comparison of UFH in hospital versus LMWH at home. These trials showed that patients treated at home with LMWH were less likely to have recurrence of VTE events than those given hospital treatment with UFH or LMWH (fixed-effect risk ratio (RR) 0.58, 95% confidence interval (CI) 0.39 to 0.86; 6 studies; 1708 participants; P = 0.007; low-quality evidence). No clear difference was seen between groups for major bleeding (RR 0.67, 95% CI 0.33 to 1.36; 6 studies; 1708 participants; P = 0.27; low-quality evidence), minor bleeding (RR 1.29, 95% CI 0.94 to 1.78; 6 studies; 1708 participants; P = 0.11; low-quality evidence), or mortality (RR 0.69, 95% CI 0.44 to 1.09; 6 studies; 1708 participants; P = 0.11; low-quality evidence). The included studies reported no cases of venous gangrene. We could not combine patient satisfaction and quality of life outcomes in meta-analysis owing to heterogeneity of reporting, but two of three studies found evidence that home treatment led to greater improvement in quality of life compared with in-patient treatment at some point during follow-up, and the third study reported that a large number of participants chose to switch from in-patient care to home-based care for social and personal reasons, suggesting it is the patient's preferred option (very low-quality evidence). None of the studies included in this review carried out a full cost-effectiveness analysis. However, a small randomised economic evaluation of the two alternative treatment settings involving 131 participants found that direct costs were higher for those in the in-patient group. These findings were supported by three other studies that reported on their costs (very low-quality evidence).Quality of evidence for data from meta-analyses was low to very low. This was due to risk of bias, as many of the included studies used unclear randomisation techniques, and blinding was a concern for many. Also, indirectness was a concern, as most studies included a large number of participants randomised to the home (LMWH) treatment group who were treated in hospital for some or all of the treatment period. A further issue for some outcomes was heterogeneity that was evident in measurement and reporting of outcomes.

AUTHORS' CONCLUSIONS

Low-quality evidence suggests that patients treated at home with LMWH are less likely to have recurrence of VTE than those treated in hospital. However, data show no clear differences in major or minor bleeding, nor in mortality (low-quality evidence), indicating that home treatment is no worse than in-patient treatment for these outcomes. Because most healthcare systems are moving towards more LMWH usage in the home setting it is unlikely that additional large trials will be undertaken to compare these treatments. Therefore, home treatment is likely to become the norm, and further research will be directed towards resolving practical issues by devising local guidelines that include clinical prediction rules, developing biomarkers and imaging that can be used to tailor therapy to disease severity, and providing training for community healthcare workers who administer treatment and monitor treatment progress.

Ambulatory Versus In-Hospital Treatment of Proximal Lower-Limb Deep Vein Thrombosis in Adults: A Retrospective Cohort Study

BACKGROUND

Complications of deep vein thrombosis (DVT) are related to adequacy of initial anticoagulant therapy. In this study, we analyze consecutive patients with lower-limb proximal DVT and compare the characteristics, treatment, and clinical outcomes of patients receiving entirely ambulatory treatment versus those hospitalized for initial treatment.

METHODS

This was a retrospective study of consecutive patients with a first proximal lower-limb DVT during a 2-year period. Patients were followed for 90 days. Major end points were all-cause mortality, bleeding requiring hospitalization, and recurrent venous thromboembolism (VTE). Events were determined for patients who were hospitalized versus those treated on an entirely ambulatory basis.

RESULTS

A total of 236 patients were included in the study. Of these, 147 patients were hospitalized and 89 patients received ambulatory treatment. There were 20 fatalities-18 in-hospital and 2 in-ambulatory patients ( P = .008). By multivariable Cox regression analysis, the presence of active cancer (hazard ratio [HR] = 5.44; confidence interval [CI]: 2.16-13.7; P = .001), age (HR = 1.06; CI: 1.02-1.1; P = .001), and hospitalization (HR = 5.73; CI: 1.33-24.69; P = .019) were associated with death. Eight hospitalized and 2 ambulatory patients required readmission because of bleeding. Age was the only variable associated with bleeding (HR = 1.10; CI: 1.03-1.18; P = .004). There were no recurrent VTE events.

CONCLUSION

In this study of routine management of proximal DVT, we demonstrate that patients suitable for ambulatory care are adequately identified by physicians and may be treated with equal safety and efficacy to hospitalized patients.

Modest response in translation to home management of deep venous thrombosis

BACKGROUND

years may elapse between the publication of results of rigorous randomized trials and changes in clinical practice. It is not often that a definitive time interval can be identified that shows the time taken for published clinical trials to affect clinical practice. In the present study, we track the timelines of evidence for home treatment of deep venous thrombosis and its eventual impact on hospitalizations and early discharge.

METHODS

the number of patients discharged from short-stay hospitals throughout the United States between 1979 and 2006 with a principal diagnosis of deep venous thrombosis and the proportion discharged in ≤ 2 days was determined from The National Hospital Discharge Survey. We also attempted to identify all published articles that reported home treatment of deep venous thrombosis in unselected populations.

RESULTS

eleven years after demonstration of the safety and efficacy of home treatment, there was only a 21% decrease in the population-based incidence of hospitalizations of patients with a principal diagnosis of deep venous thrombosis. The proportion of patients with a principal diagnosis of deep venous thrombosis who were discharged in ≤ 2 days began to increase prominently after the 1996 publication of trials showing the safety and efficacy of home treatment, and continued to increase through 2006. However, the proportion discharged early remained modest (21% to 25%).

CONCLUSIONS

whether the slow implementation of home treatment reflects a cautious approach accompanied by a gradual testing of shortened hospitalization for deep venous thrombosis or other factors is uncertain.

Home versus in-patient treatment for deep vein thrombosis

BACKGROUND

Deep vein thrombosis (DVT) occurs when a blood clot blocks blood flow through a vein. This can happen after surgery, trauma, or when a person has been immobile. Clots can dislodge and block blood flow to the lungs, causing death. Heparin is a blood-thinning drug used in the first 3-5 days of DVT treatment. Low molecular weight heparins (LMWH) allow people with DVT to receive their initial treatment at home instead of in hospital.

OBJECTIVES

To collate randomised controlled trials (RCTs) comparing home (LMWH) versus hospital (LMWH or UH) treatment for DVT, and to compare the safety, efficacy, acceptability and cost implications of home versus hospital treatment.

SEARCH STRATEGY

We searched the Cochrane Peripheral Vascular Diseases Group trials register (inception to May 2007) and the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (last searched Issue 2, 2007) which includes searches of MEDLINE (January 1966 onwards) and EMBASE (January 1980 onwards). We also handsearched non-listed journals and contacted researchers in the field.

SELECTION CRITERIA

RCTs of home versus hospital treatment for DVT in which DVT was clinically confirmed and treated with either LMWH or UH.

DATA COLLECTION AND ANALYSIS

One reviewer selected the material for inclusion and another reviewed the literature and selection of trials. Two reviewers independently extracted data. Outcomes included PE, recurrent DVT, gangrene, heparin complications, and death.

MAIN RESULTS

Six RCTs involving 1708 participants with comparable treatment arms were included. All six had fundamental problems including high exclusion rates, partial hospital treatment of many in the LMWH arms, and comparison of UH in hospital with LMWH at home. The trials showed that patients treated at home with LMWH are less likely to have recurrence of venous thromboembolism (VTE) compared to hospital treatment with UH or LMWH (fixed effect relative risk (FE RR) 0.61; 95% confidence interval (CI) 0.42 to 0.90). Home treated patients also had lower mortality (FE RR 0.72; 95% CI 0.45 to 1.15) and fewer major bleeding (FE RR 0.67; 95% CI 0.33 to 1.36), but were more likely to have minor bleeding than those in hospital (FE RR 1.29; 95% CI 0.94 to 1.78) though these were not statistically significant.

AUTHORS' CONCLUSIONS

The limited evidence suggests that home management is cost effective and preferred by patients. Further large trials comparing these treatments are unlikely to occur. Therefore, home treatment is likely to become the norm; further research will be directed to resolving practical issues.

Management of venous thromboembolism: a clinical practice guideline from the American College of Physicians and the American Academy of Family Physicians

Venous thromboembolism is a common condition affecting 7.1 persons per 10,000 person-years among community residents. Incidence rates for venous thromboembolism are higher in men, African-Americans, and increase substantially with age. It is critical to treat deep venous thrombosis at an early stage to avoid development of further complications, such as pulmonary embolism or recurrent deep venous thrombosis. The target audience for this guideline is all clinicians caring for patients who have been given a diagnosis of deep venous thrombosis or pulmonary embolism. The target patient population is patients receiving a diagnosis of pulmonary embolism or lower-extremity deep venous thrombosis.

Microemulsions as carriers for drugs and nutraceuticals

Microemulsions are potentially excellent carriers for bioactive molecules. They offer the advantage of spontaneous formation, ease of manufacture, thermodynamic stability, and improved solubilization of bioactive materials. This review explores some of the new trends in microemulsion research through analysis of some representative studies. The solubilization of different classic drugs, peptides, and nutraceuticals in various oral microemulsion compositions and microstructures was reviewed. It was found that even W/O microemulsions, which are expected to break upon dilution in the digestive tract, increase the permeability and bioavailability of drugs. Thus, it seems that component selection (the use of molecules that can act as permeability enhancers) is of great importance. Structures such as self-microemulsifying drug delivery systems (SMEDDS), W/O, bicontinuous, and O/W microemulsions, were closely examined, and their potential to serve as drug carriers was evaluated. It seems that for microemulsion systems to be used as vehicles for bioactive materials, the formulations should be based on SMEEDS, which form O/W upon dilution to a specific water content. U-type microemulsions are actually an improved SMEDDS formulation, capable of being diluted with any given water concentration. Much research is being conducted on microemulsion microstructure since there is an obvious direct connection between the microstructure, solubilization capacity, and bioavailability of the active molecules.

Evaluation of the Oral Bioavailability of Low Molecular Weight Heparin Formulated With Glycyrrhetinic Acid as Permeation Enhancer

Low molecular weight heparin (LMWH) is the agent of choice for anticoagulant therapy and prophylaxis of thrombosis and coronary syndromes. However, its therapeutic use is limited due to poor oral bioavailability. The aim of this study was to investigate the oral delivery of LMWH, ardeparin formulated with 18-beta glycyrrhetinic acid (GA), as an alternative to currently used subcutaneous (sc) delivery. Drug transport through Caco-2 cell monolayers was monitored in the presence and absence of GA by scintillation counting and transepithelial electrical resistance. Regional permeability studies using rat intestine were performed using a modified Ussing chamber. Cell viability in the presence of various concentrations of enhancer was determined by MTT assay. The absorption of ardeparin after oral administration in rats was measured by an anti-factor Xa assay. Furthermore, the eventual mucosal epithelial damage was histologically evaluated. Higher ardeparin permeability (~7-fold) compared to control was observed in the presence of 0.02 % GA. Regional permeability studies indicated predominant absorption in the duodenal segment. Cell viability studies showed no significant cytotoxicity below 0.01 % GA. Ardeparin oral bioavailability was significantly increased (F(relative)/(S.C). = 13.3%) without causing any damage to the intestinal tissues. GA enhanced the oral absorption of ardeparin both in vitro and in vivo. The oral formulation of ardeparin with GA could be absorbed in the intestine. These results suggest that GA may be used as an absorption enhancer for the oral delivery of LMWH.

Oral delivery of chemical conjugates of heparin and deoxycholic acid in aqueous formulation

INTRODUCTION

Heparin, one of the most potent anticoagulants widely used for the treatment and prevention of deep vein thrombosis (DVT) and pulmonary embolism (PE), is currently available to patients only by parental administration. In this study, we propose a new oral delivery system of heparin by conjugating it with deoxycholic acid which reformulated by adding dimethyl sulfoxide to increase its bioavailability.

MATERIALS AND METHODS

The chemical conjugates (LMWH-DOCA) of low molecular weight heparin (4.5 kDa) with deoxycholic acid (DOCA) were synthesized by controlling the conjugation ratio. The absorption of LMWH-DOCA after its oral administration was measured by anti-FXa assay according to the conjugation ratio of DOCA, concentration of DMSO solution and dose of LMWH-DOCA, respectively. Furthermore, the incidences of mucosal damage by LMWH-DOCA in 10% DMSO solution were evaluated using H&E staining and SEM.

RESULTS

Three kinds of LMWH-DOCA were synthesized according to the DOCA conjugation ratios of LD1, LD2 and LD3, whose anticoagulant activities were 89, 86 and 85 IU/mg, respectively, and the activity of LMWH was 97 IU/mg. LMWH-DOCA was completely dissolved in 10% DMSO solution, and its bioavailability in the oral dose was significantly increased (17.6% for LD2 in 10% DMSO solution) without causing any damages in intestinal tissues.

CONCLUSIONS

The chemical conjugate of heparin and DOCA in the soluble state could be efficiently absorbed in the intestine. Therefore, we propose this system as a new strategy of oral heparin delivery for the treatment of patients who are at high risk to DVT and PE.

Cost effectiveness of bemiparin sodium versus unfractionated heparin and oral anticoagulants in the acute and long-term treatment of deep vein thrombosis

INTRODUCTION

Low-molecular-weight heparins (LMWHs) are at least as effective and well tolerated as unfractionated heparin (UFH) in the treatment of deep vein thrombosis (DVT), offering easier administration and obviating the need for anticoagulant monitoring, but have a higher acquisition cost than UFH.

OBJECTIVE

To quantify the potential economic impact of two regimens of subcutaneous bemiparin 115 IU/kg/day for 7-10 days (plus oral anticoagulants [OAC] or followed by long-term bemiparin 3500IU) versus dose-adjusted intravenous UFH for 7 days plus OAC for 3 months in the acute and long-term treatment of DVT. The representative patient was a 62-year-old, 77 kg male with proximal DVT of the lower limbs.

METHODS

A cost-effectiveness analysis was performed using a decision-tree modelling approach. The results were expressed in terms of costs (euro, 2002 values) and incremental cost effectiveness. The treatment costs (hospital stay, physician services, drug administration) and costs incurred due to complications (pulmonary embolism, recurrent DVT, bleeding events, thrombocytopenia and deaths) during the 3-month study period were considered for the primary analysis. Life expectancy and QALYs were considered for the secondary analysis. The study was performed in the setting of the Spanish National Health System.

RESULTS

Bemiparin plus OAC or long-term bemiparin for 3 months provided net cost savings of euro 769 and euro 908 per patient, respectively, compared with UFH plus OAC (UFH plus OAC euro 4128 vs bemiparin plus OAC euro 3359 vs long-term bemiparin euro 3220). Bemiparin plus OAC and long-term bemiparin for 3 months were calculated to avoid 27 and 7 additional VTE events, respectively, per 1000 patients treated. Bemiparin plus OAC or long-term bemiparin increased quality-adjusted life expectancy by approximately 1.72 and 0.74 years, respectively, compared with UFH plus OAC. The univariate sensitivity analysis supported the cost effectiveness of bemiparin in all the ranges tested for complications and costs.

CONCLUSIONS

Our model suggests that bemiparin plus OAC or long-term bemiparin for 3 months may be dominant strategies over UFH plus OAC in the treatment of DVT from the Spanish National Health System perspective, offering better outcomes and cost savings. Long-term bemiparin may be a cost-neutral alternative to bemiparin plus OAC.

Evaluation of absorption of heparin-DOCA conjugates on the intestinal wall using a surface plasmon resonance

We validated the application of the surface plasmon resonance (SPR) technique to reliably determine adhesion of drugs to the intestinal wall using heparin-DOCA conjugates, developed to enhance the oral absorption of poorly absorbed heparin. In this study, heparin conjugates, or deoxycholyl-heparin (H-DOCA) and bisdeoxycholyl-heparin (H-bis-DOCA), were synthesized by covalently coupling the synthesized succinimido deoxycholate (DOCA-NHS) or succinimido bis-deoxycholyl-L-lysine (DOCA-bis-NHS) to amine groups of heparin, and their physicochemical and biological properties were evaluated. To mimic the duodenal and ileal surfaces, duodenal and ileal brush border membrane (BBM) vesicles isolated from Sprauge-Dawley (SD) rats were immobilized onto a biosensor chip composed of dextran derivatives with modified lipophilic residues. The adhesion of heparin conjugates on the BBM surface was evaluated by measuring the SPR response signal. The adhesion of heparin conjugates was significantly dependent on the conjugated DOCA molecules: that is, they showed higher adhesion signal on the ileal BBM surface than that on the duodenal BBM surface. In particular, the solubilized heparin conjugates in DMSO solution presented significantly increased adhesion affinity on the ileal BBM surface. The adhesion of heparin conjugates on the intestinal surfaces was successfully assayed using the surface plasmon resonance technique with the sensor chip on which BBM vesicles were immobilized.

Tricaprylin microemulsion for oral delivery of low molecular weight heparin conjugates

Heparin is available to patients only by parenteral administrations due to its low oral bioavailability. For the oral delivery of low molecular weight heparin (LMWH), LMWH-DOCA was synthesized by chemical conjugation of LMWH and deoxycholic acid (DOCA) and this conjugate was formulated in a microemulsion system. The coupling ratios of DOCA to LMWH for LD1 and LD2 were 1.33 and 2.37, respectively. The microemulsion was composed of tricaprylin, surfactant mixture (Tween 80 and Span 20) and LMWH-DOCA in water, and their volume ratio was 5:3:1:1. Pharmacokinetic parameters of LMWH were not significantly changed by conjugation with DOCA; however, when LMWH-DOCA in tricaprylin microemulsion was orally administered in mice, its bioavailability was increased up to 1.5%. Furthermore, the enhancing effect of the conjugated DOCA in the tricaprylin microemulsion on the absorption of LMWH in the intestine was more significantly increased in monkey than in mice. Since the tricaprylin microemulsion could dissolve LMWH-DOCA, this formulation could maximize the enhancing effect of the conjugated DOCA on the absorption of LMWH in the intestine. Finally, it was expected that 20 mg/kg of LMWH-DOCA in the tricaprylin microemulsion was enough to prevent deep vein thrombosis (DVT) and pulmonary embolism (PE).

Outpatient therapy with low molecular weight heparin for the treatment of venous thromboembolism: a review of efficacy, safety, and costs

PURPOSE

To summarize the evidence comparing the efficacy, safety, and costs of outpatient and inpatient treatment of venous thromboembolism.

METHODS

We searched the literature through March 2002 for studies comparing outpatient and inpatient treatment of venous thromboembolism with low molecular weight heparin or unfractionated heparin, and for studies addressing the costs of low molecular weight heparin use in any setting. We included studies with comparison groups or decision analyses.

RESULTS

Eight studies (three randomized trials and five cohort studies) compared outpatient use of low molecular weight heparin with inpatient use of unfractionated heparin in 3762 patients. The incidence of recurrent deep venous thrombosis was similar in the two groups (median, 4% [range, 0% to 7%] vs. 6% [range, 0% to 9%]), as was major bleeding (median, 0.5% [range, 0% to 2%] vs. 1% [range, 0% to 2%]). Use of low molecular weight heparin was associated with shorter hospitalization (median, 2.7 days [range, 0.03 to 5.1 days] vs. 6.5 days [range, 4 to 9.6 days]) and lower costs (median difference, 1600 dollars). Comparisons of outpatient and in-hospital use of low molecular weight heparin reported no difference in outcomes, but there were savings in hospitalization costs. Low molecular weight heparin was also found to be more cost saving and cost-effective than unfractionated heparin, with savings of 0% to 64% (median, 57%).

CONCLUSION

The evidence indicates that outpatient treatment of deep venous thrombosis with low molecular weight heparin is likely to be efficacious, safe, and cost-effective.

Outpatient treatment of acute venous thromboembolic disease

Once- or twice-daily subcutaneous dosing of LMWHs without laboratory monitoring has facilitated outpatient VTE therapy. Clinical trials have demonstrated at least equivalent efficacy and safety and potential cost savings of outpatient therapy for uncomplicated proximal DVT with LMWH when compared with inpatient therapy. Explicit criteria exist for outpatient DVT therapy. Home therapy for PE requires further evaluation before it can be recommended outside of a trial or other supervised setting.

[Outpatient treatment of acute deep venous thrombosis of the lower limbs]

The outpatient management of acute deep vein thrombosis could replace the inpatient care for most patients. Fixed-dose, weight-adjusted low-molecular-weight heparins, as efficacious and safe as unfractionated heparin, allow home treatment for selected and eligible patients. The main exclusion criteria are severe renal insufficiency, high risk of bleeding, pulmonary embolism with unstable hemodynamics, allergy to heparin and suspected non-compliance. Programs for outpatient management need, after appropriate selection, adequate patient education, easy access to health-care professionals and daily follow-up during heparin treatment.

Conjugation of low-molecular-weight heparin and deoxycholic acid for the development of a new oral anticoagulant agent

BACKGROUND

Heparin administration is usually limited to intravenous or subcutaneous injection. Oral delivery of heparin is an alternative to this and has been in great demand for treating patients who are at a high risk of deep vein thrombosis or pulmonary embolism. In this study, new heparin derivatives were synthesized to enhance the oral absorption of heparin in the gastrointestinal tract. Methods and Results- By using heparin of 3000 Da [LMWH(3 kDa)], heparin of 6000 Da [LMWH(6 kDa)], and unfractionated heparin (UFH), we synthesized 3 kinds of conjugates of heparin and deoxycholic acid (DOCA): LMWH(3 kDa)-DOCA, LMWH(6 kDa)-DOCA, and UFH-DOCA. After oral administration of 100 mg/kg of heparin-DOCA, the maximum activated partial thromboplastin times of the LMWH(3 kDa)-DOCA, LMWH(6 kDa)-DOCA, and UFH-DOCA were 31.0+/-6.0, 87.8+/-11.1, and 51.0+/-8.7 seconds, respectively. The peak plasma concentrations of LMWH(3 kDa)-DOCA, LMWH(6 kDa)-DOCA, and UFH-DOCA were 0.06+/-0.02, 0.76+/-0.15, and 0.41+/-0.13 IU/mL, respectively. The bioavailability of LMWH(6 kDa)-DOCA at the 20-mg/kg dosage was calculated to be 7.8%.

CONCLUSIONS

LMWH(6 kDa)-DOCA was found to have a high anticoagulant effect when administered orally and could be used as a new oral anticoagulant agent. Furthermore, the present work proposed a new method for oral delivery of macromolecules and polysaccharide drugs.

Home versus in-patient treatment for deep vein thrombosis

BACKGROUND

Deep vein thrombosis (DVT) affects 1-2/1,000 of the adult population per annum in western societies. It may be associated with pulmonary embolism (PE) which carries a 10% fatality rate. Sufferers may develop post-thrombotic syndrome with swelling of the leg, secondary varicose veins and ulceration. In the initial stages of treatment for DVT patients are traditionally admitted to hospital for intravenous treatment with unfractionated heparin (UH) for three to five days. The dose of UH required to provide a therapeutic level of anticoagulation is unpredictable, so the blood must be closely monitored. Fractionated, or low molecular weight heparin (LMWH), is given subcutaneously once daily and requires no monitoring, so can be given in hospital or at home.

OBJECTIVES

To collate all randomised controlled trials (RCTs) comparing a home treatment regime (LMWH) with hospital treatment (LMWH or UH) for the initial phase of treatment for DVT, and to compare the safety, efficacy, patient acceptability and cost implications of home versus in-patient treatment.

SEARCH STRATEGY

All published reports of home treatment were traced through MEDLINE, and EMBASE (up to and including December 2000) using the search strategy described by the Cochrane Peripheral Vascular Diseases Group. Additional searches included the Cochrane CCTR/CENTRAL database, handsearching non-listed journals, and personal communication with researchers.

SELECTION CRITERIA

RCTs of home versus hospital treatment for DVT in which DVT was clinically confirmed and treated with either LMWH or UH.

DATA COLLECTION AND ANALYSIS

One reviewer selected the material for inclusion (IGS): the other (AAM) reviewed the literature and selection of trials. Outcomes included PE, recurrent DVT, gangrene, heparin complications, and death.

MAIN RESULTS

Only two major RCTs with comparable treatment arms were found. Both had fundamental problems including high exclusion rates, partial hospital treatment of many in the LMWH arms, and comparison of UH in hospital with LMWH at home. The trials showed that home treatment was no more liable to complications than hospital treatment. Initial results from a smaller RCT comparing LMWH treatment in both home and hospital arms came to the same conclusion.

REVIEWER'S CONCLUSIONS

The limited evidence suggests that home management is cost effective, and likely to be preferred by patients. Further large trials comparing these treatments are unlikely to be held. Therefore, home treatment is likely to become the norm, and further research will be directed to resolving practical issues.