ximelagatran and Postoperative-Complications

After arthroplasty treatment, some complications commonly occur, such as early revision, infection/dislocation, and venous thromboembolism (VTE). This study aims to use a network meta-analysis to compare effects of 9 anticoagulant drugs (edoxaban, dabigatan, apixaban, rivaroxaban, warfarin, heparin, bemiparin, ximelagatran, and enoxaparin) in preventing postoperative complications in arthroplasty patients.. After retrieving PubMed, Embase, and Cochrane Library database from the inception to November 2016, randomized controlled trials were enrolled. The integration of direct and indirect evidences was performed to calculate odd ratios and the surface under the cumulative ranking curves. Nineteen eligible randomized controlled trials were included.. The network meta-analysis results showed that compared with warfarin, edoxaban, apixaban, and rivaroxaban had a lower incidence rate in asymptomatic deep venous thrombosis, which indicated that edoxaban, apixaban, and rivaroxaban had better effects on prevention. Similarly, in comparison to enoxaparin, edoxaban and rivaroxaban had better effect; rivaroxaban was better than ximelagatran in preventive effects. Compared with apixaban, edoxaban, dabigatan, rivaroxaban, and enoxaparin had a higher incidence rate in clinically relevant non-major bleeding, which showed that preventive effects were relatively poor. In addition, the results of the surface under the cumulative ranking curves showed that rivaroxaban and bemiparin worked best on symptomatic deep venous thrombosis and pulmonary embolism. In terms of bleeding, apixaban and warfarin had better preventive effects.. Our findings suggested that rivaroxaban may work better in terms of symptomatic deep venous thrombosis and pulmonary embolism, whereas apixaban had better preventive effects in bleeding.

Topics: Anticoagulants; Arthroplasty; Azetidines; Benzylamines; Dabigatran; Enoxaparin; Heparin; Heparin, Low-Molecular-Weight; Humans; Network Meta-Analysis; Postoperative Complications; Pulmonary Embolism; Pyrazoles; Pyridines; Pyridones; Rivaroxaban; Thiazoles; Treatment Outcome; Venous Thromboembolism; Warfarin

Topics: Anticoagulants; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Azetidines; Benzylamines; Clinical Trials, Phase III as Topic; Fibrinolytic Agents; Fondaparinux; Glycine; Humans; Polysaccharides; Postoperative Complications; Pulmonary Embolism; Thromboembolism; Venous Thrombosis

Use of low molecular weight heparin (LMWH) is standard practice for preventing postoperative venous thromboembolism (VTE). Ximelagatran is a new direct thrombin inhibitor for this indication.. A systematic review was conducted to compare the efficacy and safety of LMWH with ximelagatran in orthopaedic surgery.. Six eligible, well conducted clinical trials (10 051 patients) were identified. Overall, the risk of VTE (OR (odds ratio) 1.22 (95 per cent confidence interval (c.i.) 0.89 to 1.67)) and serious bleeding (OR 0.70 (95 per cent c.i. 0.42 to 1.18)) was not significantly different for LMWH compared with ximelagatran. Exploratory analyses to investigate statistical heterogeneity found that results varied by surgical subtype and treatment regimen. Compared with postoperative ximelagatran, LMWH had a significantly lower rate of VTE (OR 0.68 (95 per cent c.i. 0.56 to 0.82); P < 0.001), with no significant difference in bleeding rate (OR 1.09 (95 per cent c.i. 0.62 to 1.94); P = 0.76), in hip surgery, and no significant differences in knee surgery. When ximelagatran was started immediately before surgery, LMWH had a significantly higher rate of VTE in both hip (OR 1.87 (95 per cent c.i. 1.20 to 2.92); P = 0.006) and knee (OR 1.49 (95 per cent c.i. 1.14 to 1.93); P = 0.003) surgery, but less bleeding: hip OR 0.30 (95 per cent c.i. 0.17 to 0.53; P < 0.001); knee OR 0.71 (95 per cent c.i. 0.30 to 1.67; P = 0.43).. This review demonstrated no overall advantage for either LMWH or ximelagatran in thromboprophylaxis following orthopaedic surgery. Benefits in VTE prevention with ximelagatran were gained at the expense of an increased risk of serious bleeding.

Topics: Adult; Anticoagulants; Arthroplasty, Replacement; Arthroplasty, Replacement, Hip; Azetidines; Benzylamines; Heparin, Low-Molecular-Weight; Humans; Postoperative Complications; Postoperative Hemorrhage; Randomized Controlled Trials as Topic; Thromboembolism; Venous Thrombosis

Topics: Azetidines; Benzylamines; Fibrinolytic Agents; Heparin, Low-Molecular-Weight; Humans; Orthopedic Procedures; Postoperative Complications; Therapeutic Equivalency; Thromboembolism; Venous Thrombosis; Vitamin K

The oral direct thrombin inhibitor ximelagatran shows great promise for prevention of venous thromboembolic events following major elective orthopaedic surgery. Its consistent and predictable pharmacokinetics and pharmacodynamics across a wide range of patient populations allow administration with fixed dosing and with no coagulation monitoring. In orthopaedic surgery clinical trials, ximelagatran was effective and well tolerated compared with standard therapy, with dose and timing relative to surgery important factors in determining its optimal profile. In European trials, an initial 3-mg postoperative dose of subcutaneous melagatran, the active form of ximelagatran, followed by oral ximelagatran 24 mg twice daily achieved similar efficacy and safety to enoxaparin. Although the risk of spinal haematoma following neuraxial anaesthesia is rare, it is increased by the concomitant use of anticoagulants. In orthopaedic surgery trials with ximelagatran to date, complications such as spinal haematoma have not been reported. The pharmacokinetic profile of ximelagatran suggests that concurrent use with neuraxial anaesthesia should require no further precautions than those currently necessary with low-molecular-weight heparin.

Topics: Administration, Oral; Anesthesia; Anticoagulants; Azetidines; Benzylamines; Clinical Trials as Topic; Humans; Orthopedic Procedures; Postoperative Complications; Thrombin; Thromboembolism; Venous Thrombosis

Every year, approximately 2 million people experience a deep venous thrombosis (DVT). Approximately 600,000 of these people are diagnosed with a pulmonary embolism and about 10% of these die. It has been established that surgery, anesthesia, and bed rest increase the risk of DVT, and therefore, patients who undergo a major lower-extremity procedure should receive prophylaxis. During the past 10 years, the choices of pharmacological and mechanical prophylaxis have increased greatly. Warfarin is probably the most widely used prophylactic method in the U.S., but low-molecular-weight heparin (LMWH) use has increased. Also available is a synthetic pentasaccharide that acts as an anti-Xa inhibitor to decrease DVT without increase in bleeding. All but warfarin are given by subcutaneous injection and require no laboratory management to adjust the medication. Another drug in clinical trials is a direct thrombin inhibitor taken orally in a fixed dose that does not require monitoring. Non-pharmacological prophylaxis and/or stacked modalities, although used, have not shown the efficacy of pharmacological prophylaxis. With the incidence of DVT reported in the range of 41% to 85% without prophylaxis in joint replacement and hip-fracture surgery, prophylaxis is warranted in all lower-extremity joint replacement and hip-fracture patients.

Topics: Anticoagulants; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Azetidines; Benzylamines; Fondaparinux; Heparin, Low-Molecular-Weight; Humans; Polysaccharides; Postoperative Complications; Pulmonary Embolism; Venous Thrombosis; Warfarin

Topics: Anticoagulants; Azetidines; Benzylamines; Humans; Myocardial Infarction; Orthopedic Procedures; Postoperative Complications; Stroke; Venous Thrombosis

Patients who undergo orthopaedic surgery are at substantially increased risk for venous thromboembolic events. These include proximal and distal deep vein thrombosis, with the former more likely to lead to pulmonary embolism and fatal complications. Anticoagulants are routinely used for venous thromboembolism prophylaxis in patients undergoing total hip or total knee replacement surgery. Although current treatments offer effective prophylaxis, they have disadvantages. Warfarin is limited by the requirement for coagulation monitoring to ensure effective and safe use. Similarly, low-molecular-weight heparins (LMWHs) have disadvantages, including the need for parenteral administration. This article brings together data from clinical trials of the novel oral direct thrombin inhibitor, ximelagatran, in the prevention of venous thromboembolism in patients undergoing elective total hip or total knee replacement. The ximelagatran clinical trial programme in orthopaedic surgery has focused primarily on five large multicentre studies in Europe (the Melagatran Thromboprophylaxis in Orthopaedic surgery II and III and Expanded Prophylaxis Evaluation Surgery Study studies) and in the United States (the Exanta Used to Lessen Thrombosis A and B studies), which enrolled more than 8000 patients. In addition, the USA clinical trial programme included three other trials that investigated ximelagatran in orthopaedic surgery; two of these studies focused on prevention of venous thromboembolism after total knee replacement, and one study investigated prevention of venous thromboembolism after total hip replacement. These studies compared ximelagatran with the LMWHs dalteparin and enoxaparin and with warfarin, and were designed to reflect regional differences in venous thromboembolism prophylaxis and to build on findings from previous studies. Generally, ximelagatran has been shown to possess comparable or greater efficacy relative to comparators. The timing and dose of ximelagatran have been shown to be important determinants of its efficacy and safety. As ximelagatran can be given in fixed oral dosing without coagulation monitoring, it is an attractive choice for the prevention of venous thromboembolism in major elective orthopaedic surgery.

Topics: Administration, Oral; Anticoagulants; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Azetidines; Benzylamines; Clinical Trials as Topic; Heparin, Low-Molecular-Weight; Humans; Multicenter Studies as Topic; Postoperative Complications; Pulmonary Embolism; Thrombin; Venous Thrombosis

Current antithrombotic therapies are associated with various practical limitations and risks that restrict their utility in the management of venous thromboembolism. The coagulation factor, thrombin, has been the focus of extensive investigation as a pharmacological target in efforts to improve the management of venous thromboembolism. Hirudin, desirudin, bivalirudin and argatroban are direct thrombin inhibitors that have been launched for limited indications as anticoagulants. Their usefulness for long-term prophylaxis is limited by a requirement for parenteral administration, restricted licensing and bleeding/tolerability profile. Ximelagatran--which, after oral administration, is rapidly converted to its active form, melagatran--is the first oral direct thrombin inhibitor and the first new oral anticoagulant to become available in 60 years. Clinical studies have shown that melagatran/ximelagatran, without coagulation monitoring, is effective and well tolerated for the prevention of venous thromboembolism after hip replacement and knee replacement surgery. Ximelagatran is also effective in the acute treatment of venous thromboembolism and long-term secondary prevention of recurrent venous thromboembolism, the prevention of stroke in patients with atrial fibrillation and in the prevention of cardiovascular events after myocardial infarction. Oral direct thrombin inhibitors have a promising role in the management of venous thromboembolism and other associated medical conditions.

Topics: Anticoagulants; Azetidines; Benzylamines; Clinical Trials as Topic; Humans; Orthopedic Procedures; Postoperative Complications; Thrombin; Venous Thrombosis

A new generation of antithrombotic agents that target a single enzyme within the procoagulant cascade is making its way into mainstream clinical practice. Borrowing selectively from the properties of their parent anticoagulant, unfractionated heparin, as well as from those of peptide anticoagulants from reptile or insect venoms, designers of the new drugs have created targeted inhibitors of thrombin, factor Xa, or other specific factors in the procoagulant pathways. These new agents promise efficacy and safety profiles far more favorable than those of conventional anticoagulants for thromboprophylaxis after major orthopedic surgery and require no laboratory monitoring of drug efficacy in this setting. Ximelagatran, the oral "prodrug" of the direct thrombin inhibitor melagatran, is in phase III of clinical development. Clinical trials using various dosages of ximelagatran, sometimes preceded by subcutaneous melagatran, as thromboprophylaxis after total hip or knee replacement surgery have suggested efficacy equal to or better than that of warfarin and enoxaparin. The best dosing regimen and optimal timing of first dose for melagatran and ximelagatran remain to be determined, as do the mechanism and impact of drug disturbance of hepatic function. Fondaparinux, a selective, synthetic inhibitor of factor Xa, has been shown in large clinical trials to be superior to low-molecular-weight heparins and is approved as a fixed once-daily subcutaneous 2.5-mg dose for thromboprophylaxis for hip or knee replacement surgery and after hip fracture repair. Fixed-dose fondaparinux 2.5 mg initiated 6 to 8 hours after surgery achieved superior efficacy and comparable safety in head-to-head comparisons with enoxaparin for the prevention of venous thromboembolism after major orthopedic surgery. Fondaparinux is the only agent approved for use in hip fracture patients in the United States at this time and has recently gained approval for extended prophylaxis in this patient population.

Topics: Anticoagulants; Azetidines; Benzylamines; Clinical Trials as Topic; Factor Xa Inhibitors; Fondaparinux; Glycine; Heparin; Heparin, Low-Molecular-Weight; Humans; Models, Biological; Orthopedics; Polysaccharides; Postoperative Complications; Thromboembolism; Thrombolytic Therapy

Anticoagulants are widely used for the prevention and treatment of venous and arterial thrombosis. Current treatment strategies often employ a combination of parenteral and oral agents because the only available orally active anticoagulants, vitamin K antagonists, have a delayed onset of action. Furthermore, vitamin K antagonists have a narrow therapeutic window that necessitates careful anticoagulation monitoring, and dosing is problematic because of multiple food and drug interactions. These limitations highlight the need for oral anticoagulants that produce a more predictable anticoagulant response than vitamin K antagonists, thereby obviating the need for laboratory monitoring. Ximelagatran has the potential to meet this need. A prodrug of melagatran, an agent that targets thrombin, ximelagatran exhibits many of the characteristics of an ideal anticoagulant. This article (1). reviews the limitations of vitamin K antagonists, (2). lists the characteristics of an ideal anticoagulant, (3). rationalizes thrombin as a target for new anticoagulants, (4). reviews the preclinical and clinical data with ximelagatran, and (5). provides clinical perspective as to the future of ximelagatran and other orally active anticoagulants currently under development.

Topics: Administration, Oral; Anticoagulants; Atrial Fibrillation; Azetidines; Benzylamines; Blood Coagulation; Drug Monitoring; Glycine; Humans; International Normalized Ratio; Postoperative Complications; Prodrugs; Stroke; Thrombin; Thrombosis; Venous Thrombosis; Vitamin K

Ximelagatran, the first oral direct thrombin inhibitor, was shown to be an effective antithrombotic agent but was associated with potential liver toxicity after prolonged administration.. The aim of the EXTEND study was to assess safety and efficacy of extended administration (35 days) of ximelagatran or enoxaparin for the prevention of venous thromboembolism after elective hip replacement and hip fracture surgery. A follow-up period, including assessment of liver enzymes (in particular alanine aminotransferase; ALAT), until post-operative day 180 was planned, with visits at days 56 and 180.. Randomization and administration of study drugs were stopped following a report of serious liver injury occurring 3 weeks after completion of ximelagatran treatment. At the time of study termination, 1158 patients had been randomized and 641 had completed the 35-day treatment; with 303 ximelagatran and 265 enoxaparin patients remaining in the study through to the day 56 follow-up visit. Overall, 58 patients showed an ALAT increase to >2x upper limit of normal: 31 treated with enoxaparin, 27 with ximelagatran. Three ximelagatran patients also showed symptoms potentially related to liver toxicity. Eleven ximelagatran patients showed an ALAT increase after study treatment ended. The clinical development of ximelagatran was terminated and the drug withdrawn from the market. Evaluation of the relative efficacy of the two treatments as specified in the protocol was impossible due to the premature termination of the study.. Prolonged administration of ximelagatran was associated with an increased risk of liver toxicity. In a substantial proportion of patients, ALAT increase occurred after treatment withdrawal. The findings seen with ximelagatran should be considered when designing studies with new antithrombotic agents.

Topics: Adult; Aged; Aged, 80 and over; Alanine Transaminase; Anticoagulants; Arthroplasty, Replacement, Hip; Azetidines; Benzylamines; Double-Blind Method; Enoxaparin; Female; Hip Fractures; Humans; Liver; Male; Middle Aged; Postoperative Complications; Time Factors; Venous Thromboembolism

We evaluated whether a postoperative regimen with melagatran followed by oral ximelagatran, two new direct thrombin inhibitors, was an optimal regimen for thromboprophylaxis in major orthopaedic surgery. In a double-blind study, 2788 patients undergoing total hip or knee replacement were randomly assigned to receive for 8 to 11 days either 3 mg of subcutaneous melagatran started 4-12 h postoperatively, followed by 24 mg of oral ximelagatran twice-daily or 40 mg of subcutaneous enoxaparin once-daily, started 12 h preoperatively. Ximelagatran was to be initiated within the first two postoperative days. The primary efficacy endpoint was venous thromboembolism (deep-vein thrombosis detected by mandatory venography, pulmonary embolism or unexplained death). The main safety endpoint was bleeding. Venous thromboembolism occurred in 355/1146 (31.0%) and 306/1122 (27.3%) patients in the ximelagatran and enoxaparin group, respectively, a difference in risk of 3.7% in favour of enoxaparin (p = 0.053). Bleeding was comparable between the two groups.

Topics: Administration, Oral; Adult; Aged; Aged, 80 and over; Anticoagulants; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Azetidines; Benzylamines; Cause of Death; Double-Blind Method; Drug Administration Schedule; Enoxaparin; Female; Glycine; Hemorrhage; Humans; Injections, Subcutaneous; Male; Middle Aged; Postoperative Complications; Prodrugs; Prospective Studies; Pulmonary Embolism; Safety; Thrombin; Treatment Outcome; Venous Thrombosis

Ximelagatran, an oral direct thrombin inhibitor, is rapidly bioconverted to melagatran, its active form. The objective of this population analysis was to characterise the pharmacokinetics of melagatran and its effect on activated partial thromboplastin time (APTT), an ex vivo measure of coagulation time, in orthopaedic surgery patients sequentially receiving subcutaneous melagatran and oral ximelagatran as prophylaxis for venous thromboembolism. To support the design of a pivotal dose-finding study, the impact of individualised dosage based on bodyweight and calculated creatinine clearance was examined.. Pooled data obtained in three small dose-guiding studies were analysed. The patients received twice-daily administration, with either subcutaneous melagatran alone or a sequential regimen of subcutaneous melagatran followed by oral ximelagatran, for 8-11 days starting just before initiation of surgery. Nonlinear mixed-effects modelling was used to evaluate rich data of melagatran pharmacokinetics (3326 observations) and the pharmacodynamic effect on APTT (2319 observations) in samples from 216 patients collected in the three dose-guiding trials. The pharmacokinetic and pharmacodynamic models were validated using sparse data collected in a subgroup of 319 patients enrolled in the pivotal dose-finding trial. The impact of individualised dosage on pharmacokinetic and pharmacodynamic variability was evaluated by simulations of the pharmacokinetic-pharmacodynamic model.. The pharmacokinetics of melagatran were well described by a one-compartment model with first-order absorption after both subcutaneous melagatran and oral ximelagatran. Melagatran clearance was correlated with renal function, assessed as calculated creatinine clearance. The median population clearance (creatinine clearance 70 mL/min) was 5.3 and 22.9 L/h for the subcutaneous and oral formulations, respectively. The bioavailability of melagatran after oral ximelagatran relative to subcutaneous melagatran was 23%. The volume of distribution was influenced by bodyweight. For a patient with a bodyweight of 75kg, the median population estimates were 15.5 and 159L for the subcutaneous and oral formulations, respectively. The relationship between APTT and melagatran plasma concentration was well described by a power function, with a steeper slope during and early after surgery but no influence by any covariates. Simulations demonstrated that individualised dosage based on creatinine clearance or bodyweight had no clinically relevant impact on the variability in melagatran pharmacokinetics or on the effect on APTT.. The relatively low impact of individualised dosage on the pharmacokinetic and pharmacodynamic variability of melagatran supported the use of a fixed-dose regimen in the studied population of orthopaedic surgery patients, including those with mild to moderate renal impairment.

Topics: Administration, Cutaneous; Administration, Oral; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Azetidines; Benzylamines; Biological Availability; Body Weight; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Glycine; Humans; Metabolic Clearance Rate; Partial Thromboplastin Time; Postoperative Complications; Sweden; Thromboembolism; Venous Thrombosis; Whole Blood Coagulation Time

The efficacy and safety of the new oral, direct and selective thrombin inhibitor Ximelagatran and its active form Melagatran was analysed in patients undergoing total hip or knee replacement.. Methro II, a randomised, double-blind controlled dose-finding study, involved 1876 patients. Melagatran (1, 1.5, 2.25 or 3 mg; twice daily; start: immediately before surgery) was given subcutaneously, followed by orally administered Ximelagatran (8, 12, 18 or 24 mg, twice daily, day after surgery) and compared to subcutaneously administered dalteparin (5000 IE, once daily). Methro III was a randomised, double blind controlled study involving 2788 patients. The fixed dose of 3 mg Melagatran was given (start: 4-12 hours postoperatively) followed by oral Ximelagatran (24 mg, twice daily, day after surgery) compared to subcutaneous enoxaparin (40 mg, once daily). In both studies, dalteparin or enoxaparin was applied at the evening before operation; the treatment lasted 8 to 11 days. A bilateral venography was performed at the last day of treatment.. In the Methro II study, 1270 patients underwent total hip, 606 total knee replacement. In both groups the thromboembolism rate was reduced depending on the dose of Ximelagatran/Melagatran. Compared to dalteparin, it was significantly lower for the Ximelagatran/Melagatran group with the highest dose. In the Methro III study 1923 patients underwent a total hip, 865 a total knee replacement. The thromboembolism rate was 31% for the Ximelagatran/Melagatran group compared to 27% for the enoxaparin group. In both studies blood loss and transfusion requirement were in the same range as with low weight molecular heparins.. A fixed subcutaneously given dose of Melagatran, followed by orally administered Ximelagatran is effective and well tolerated as prophylaxis against venous thromboembolism.

Topics: Administration, Oral; Antithrombins; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Azetidines; Benzylamines; Double-Blind Method; Humans; Postoperative Complications; Prodrugs; Thromboembolism

Heparins substantially reduce the risk of thromboembolic complications after total hip or knee replacement. However, they can be given only by injection and have several other drawbacks. We did a multicentre, randomised, double-blind study to examine the dose-response relation of subcutaneous melagatran, a direct thrombin inhibitor, followed by oral ximelagatran as thromboprophylaxis after total hip or knee replacement. We aimed to compare the efficacy and safety with that of dalteparin.. Of 1900 patients, 1495 were assigned to four dose categories of subcutaneous melagatran from just before surgery (1.00 mg, 1.50 mg, 2.25 mg, or 3.00 mg twice daily) followed from the day after surgery by oral ximelagatran (8 mg, 12 mg, 18 mg, or 24 mg twice daily). 381 patients were assigned subcutaneous dalteparin 5000 IU once daily, from the evening before surgery. Bilateral venography was done at 7-10 days, and clinically suspected venous thromboembolism (VTE) was confirmed radiologically. The primary endpoint was the rate of deep-vein thrombosis and pulmonary embolism (PE). Analyses were by intention to treat.. 1876 patients underwent total replacement of hip (n=1270) or knee (n=606); evaluable venograms were obtained in 1473 (79%). Four patients without evaluable venograms had PE. Overall, a significant dose-dependent decrease in VTE was seen with melagatran/ximelagatran (lowest to highest group: 111 [37.8%], 70 [24.1%], 71 [23.7%], and 43 [15.1%]; p=0.0001); there were also significant relations for both total hip and total knee replacement individually. The frequency of VTE was significantly lower with the highest dose of melagatran/ximelagatran than with dalteparin (15.1% vs 28.2%, p<0.0001). There were no reoperations due to bleeding and no critical organ bleeding. Excessive surgical bleeding was uncommon but more frequent in the highest dose group.. This sequential therapy was effective and safe in patients undergoing major joint replacement surgery. The findings should be confirmed in a large phase III trial.

Topics: Adult; Aged; Anticoagulants; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Azetidines; Benzylamines; Dalteparin; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Female; Glycine; Humans; Male; Middle Aged; Postoperative Complications; Prodrugs; Thromboembolism

The novel, oral direct thrombin inhibitor, ximelagatran (formerly H 376/95), represents an advance in antithrombotic therapy through its oral availability. After oral administration, ximelagatran is converted to its active form, melagatran. Melagatran can also be administered subcutaneously (s.c.). The results from the first clinical study with ximelagatran are reported. In this randomized, parallel-group, controlled study, 103 patients scheduled for elective total hip or total knee replacement received s.c. melagatran (1, 2 or 4 mg bid) for 2 days commencing immediately before surgery, followed by oral ximelagatran (6, 12 or 24 mg bid) for 6-9 days. Another 33 patients received dalteparin 5000 IU s.c. once daily, started the evening before surgery, for 8-11 days. At bilateral venography, deep vein thrombosis was found in 20.5% (16/78) of patients who had received s.c. melagatran and oral ximelagatran and in 18.5% (5/27) of patients in the dalteparin group. The study did not evaluate a dose-response for efficacy, and no differences between the three dose levels of melagatran and ximelagatran were shown. No pulmonary embolism was diagnosed during treatment. Total bleeding in the s.c. melagatran plus oral ximelagatran groups showed no dose-response and was similar to that seen in the dalteparin group. The pharmacokinetic properties of melagatran in the surgery patients were consistent with those observed for healthy subjects, and the APTT ratio, which increased non-linearly with plasma melagatran concentration, showed a consistent concentration-effect relationship during the treatment period. Ximelagatran and melagatran were well tolerated. In conclusion, ximelagatran and its active form melagatran appear to be promising agents for the prevention of venous thromboembolism following orthopaedic surgery.

Topics: Administration, Oral; Adolescent; Aged; Aged, 80 and over; Anticoagulants; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Azetidines; Benzylamines; Dalteparin; Female; Glycine; Humans; Incidence; Injections, Subcutaneous; Male; Middle Aged; Partial Thromboplastin Time; Postoperative Complications; Prodrugs; Safety; Sweden; Thrombin; Thromboembolism; Treatment Outcome; Venous Thrombosis

Patients (n = 1600) from 12 European countries, scheduled for elective orthopaedic hip or knee surgery, were screened for Factor V Leiden and prothrombin gene G20210A mutations, found in 5.5% and 2.9% of the populations, respectively. All patients underwent prophylactic treatment with one of four doses of melagatran and ximelagatran or dalteparin, starting pre-operatively. Bilateral ascending venography was performed on study day 8-11. The patients were subsequently treated according to local routines and followed for 4-6 weeks postoperatively. The composite endpoint of screened deep vein thrombosis (DVT) and symptomatic pulmonary embolism (PE) during prophylaxis did not differ significantly between patients with or without these mutations. Symptomatic venous thromboembolism (VTE) during prophylaxis and follow-up (1.9%) was significantly over-represented among patients with the prothrombin gene G20210A mutation (p = 0.0002). A tendency towards increased risk of VTE was found with the Factor V Leiden mutation (p = 0.09). PE were few, but significantly over-represented in both the Factor V Leiden and prothrombin gene G20210A mutated patients (p = 0.03 and p = 0.05, respectively). However, since 90% of the patients with these genetic risk factors will not suffer a VTE event, a general pre-operative genotyping is, in our opinion, of questionable value.

Topics: Activated Protein C Resistance; Adolescent; Adult; Aged; Aged, 80 and over; Anticoagulants; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Azetidines; Benzylamines; Dalteparin; DNA Mutational Analysis; Double-Blind Method; Europe; Factor V; Female; Genetic Predisposition to Disease; Genotype; Glycine; Humans; Male; Middle Aged; Postoperative Complications; Promoter Regions, Genetic; Prospective Studies; Prothrombin; Pulmonary Embolism; Risk Factors; Thrombophilia; Venous Thrombosis

Up to one third of patients who undergo total knee replacement develop deep vein thrombosis after surgery despite receiving low-molecular-weight heparin prophylaxis. Ximelagatran is a novel direct inhibitor of free and clot-bound thrombin.. We performed a randomized, parallel, dose-finding study of 600 adults undergoing elective total knee replacement at 68 North American hospitals to determine the optimum dose of ximelagatran to use as prophylaxis against venous thromboembolism after total knee replacement. Patients received either ximelagatran twice daily by mouth in blinded fixed doses of 8, 12, 18, or 24 mg or open-label enoxaparin sodium, 30 mg, subcutaneously twice daily, starting 12 to 24 hours after surgery and continuing for 6 to 12 days. We measured the 6- to 12-day cumulative incidence of symptomatic or venographic deep vein thrombosis, symptomatic pulmonary embolism, and bleeding.. A total of 594 patients received at least 1 dose of the study drug; 443 patients were evaluable for efficacy. Rates of overall venous thromboembolism (and proximal deep vein thrombosis or pulmonary embolism) for the 8-, 12-, 18-, and 24-mg doses of ximelagatran were 27% (6.6%), 19.8% (2.0%), 28.7% (5.8%), and 15.8% (3.2%), respectively. Rates of overall venous thromboembolism (22.7%) and proximal deep vein thrombosis or pulmonary embolism (3.1%) for enoxaparin did not differ significantly compared with 24-mg ximelagatran (overall difference, -6.9%; 95% confidence interval, -18.0% to 4.2%; P=.3). There was no major bleeding with administration of 24 mg of ximelagatran twice daily.. Fixed-dose, unmonitored ximelagatran, 24 mg twice daily, given after surgery appears to be safe and effective oral prophylaxis against venous thromboembolism after total knee replacement.

Topics: Administration, Oral; Adult; Aged; Anticoagulants; Arthroplasty, Replacement, Knee; Azetidines; Benzylamines; Dose-Response Relationship, Drug; Drug Administration Schedule; Enoxaparin; Female; Humans; Injections, Subcutaneous; Male; Middle Aged; Postoperative Complications; Prodrugs; Pulmonary Embolism; Thrombin; Treatment Outcome; Venous Thrombosis

While considering long-term oral anticoagulation one should assess benefit (i.e., reduction in thromboembolic events) and risks (i.e., bleeding complications) associated with therapy for each individual patient. The classic cardiac indications for oral anticoagulation include chronic atrial fibrillation, prosthetic heart valves, and left ventricular thrombus formation following anterior myocardial infarction. The value of anticoagulation in patients with impaired left ventricular function in stable sinus rhythm and in secondary prevention of coronary artery disease remains controversial. For decades warfarin has been the only compound available. Currently, promising results have been achieved with the oral thrombin inhibitor ximelagatran. In the future, oral anticoagulants, which are administered in fixed dose with no need for monitoring of the anticoagulation level, may replace warfarin. Safety and efficacy of double antiplatelet therapy (aspirin and clopidogrel) in the secondary prevention of thromboembolic events in patients with atrial fibrillation are currently being addressed in large-scale clinical trials.

Topics: Administration, Oral; Anticoagulants; Atrial Fibrillation; Azetidines; Benzylamines; Clinical Trials as Topic; Heart Valve Prosthesis Implantation; Heart Ventricles; Humans; Long-Term Care; Myocardial Infarction; Postoperative Complications; Risk Factors; Thromboembolism; Thrombosis