Fondaparinux sodium: a review of its use in the treatment of acute venous thromboembolism

Predicting PSR filters by transverse relaxation enhancements

The paramagnetic spin relaxation (PSR) filter allows the suppression of the NMR resonances of individual components in mixtures according to their Gd(3+)-complexing ability. The difficulty in predicting this property hampers, however, the widespread application of this filter. Herein we describe that the PSR filter is dominated by the transverse relaxation enhancement (R(2p)) experienced by nuclei in the presence of Gd(3+), so that R(2p) represents a reliable predictive tool of suppression in the 1D and 2D PSR filter of complex mixtures. The robustness of R(2p) as a predictive tool in PSR filters has been demonstrated at different magnetic fields and for the (1)H, (13)C, COSY, and HMQC filtering of commercial multicomponent compositions, including beverages and drugs.

International recommendations for the prevention and treatment of venous thromboembolism associated with cancer

Venous thromboembolism (VTE) is a common complication and a leading cause of death in oncological patients. Recent guidelines have been established for the treatment and prevention of VTE in oncological patients in various clinical situations. These guidelines recommend: (a) prophylactic anticoagulation in all hospitalized oncological patients in whom there are no contraindications; (b) prophylactic anticoagulation in patients scheduled for major oncological surgery in whom there are no contraindications; (c) prolonged (>or=6 months) anticoagulant therapy in oncological patients with manifest VTE in order to prevent a new episode; (d) no routine prophylactic anticoagulation in ambulatory patients without VTE receiving chemotherapy, except when they are receiving treatment with anti-cancer agents with a high risk of thrombogenicity, such as thalidomide- or lenalidomide-based chemotherapeutic regimens; and (e) no use of prophylactic anticoagulants to improve survival in patients with cancer without manifest VTE. Although vitamin K antagonists, unfractionated heparin and in some cases fondaparinux sodium could be used for the treatment of VTE, low molecular weight heparins are recommended for initial and continuous anticoagulant treatment in oncological patients with VTE, as well as for its prevention.

Spotlight on fondaparinux sodium in acute coronary syndromes

Fondaparinux sodium (Arixtra) is a synthetic, sulfated pentasaccharide, selective factor Xa inhibitor that is indicated in Europe for preventing thrombus formation in patients with acute coronary syndromes (ACS; the focus of this review), including those with ST-segment elevation myocardial infarction (STEMI), non-STEMI (NSTEMI), or unstable angina. The large (n = 20,078), well designed OASIS-5 trial showed that subcutaneous fondaparinux 2.5 mg/day for < or =8 days was noninferior to subcutaneous enoxaparin 1 mg/kg twice daily (once daily in those with renal dysfunction) in reducing death or ischemic events at 9 days and the efficacy was maintained for up to 6 months (study end) in patients with unstable angina or NSTEMI. During this time, major bleeding occurred in fewer fondaparinux than enoxaparin recipients, resulting in a benefit : risk balance favoring fondaparinux. The incidence of death or reinfarction at 30 days was significantly lower in recipients of subcutaneous fondaparinux 2.5 mg/day than in those who received usual care (including unfractionated heparin treatment as indicated) in patients with STEMI in the large (n > 12,000) OASIS-6 trial. There were no differences in the incidence of major bleeding between these groups, resulting in a benefit : risk balance favoring fondaparinux. The specificity and selectivity of fondaparinux, combined with its long half-life and 100% bioavailability, allows once-daily anticoagulation without the need for monitoring activated clotting time. Subcutaneous fondaparinux was noninferior to enoxaparin treatment in patients with unstable angina or NSTEMI, and was more effective than usual care in those with STEMI. Fondaparinux has a favorable tolerability profile, particularly with regard to the risk of major bleeding, and limited data suggest that it is more cost effective than enoxaparin in the short term. Thus, overall, clinical evidence suggests that fondaparinux has a valuable place in the treatment of patients with ACS.

Fondaparinux sodium: a review of its use in the management of acute coronary syndromes

Fondaparinux sodium (Arixtra) is a synthetic, sulfated pentasaccharide, selective factor Xa inhibitor that is indicated in Europe for preventing thrombus formation in patients with acute coronary syndromes (ACS; the focus of this review), including those with ST-segment elevation myocardial infarction (STEMI), non-STEMI (NSTEMI), or unstable angina.The large (n = 20,078), well designed OASIS-5 trial showed that subcutaneous fondaparinux 2.5 mg/day for <or=8 days was noninferior to subcutaneous enoxaparin 1 mg/kg twice daily (once daily in those with renal dysfunction) in reducing death or ischemic events at 9 days and the efficacy was maintained for up to 6 months (study end) in patients with unstable angina or NSTEMI. During this time, major bleeding occurred in fewer fondaparinux than enoxaparin recipients, resulting in a benefit: risk balance favoring fondaparinux. The incidence of death or reinfarction at 30 days was significantly lower in recipients of subcutaneous fondaparinux 2.5 mg/day than in those who received usual care (including unfractionated heparin [UFH] treatment as indicated) in patients with STEMI in the large (n > 12,000) OASIS-6 trial. There were no differences in the incidence of major bleeding between these groups, resulting in a benefit : risk balance favoring fondaparinux. The specificity and selectivity of fondaparinux, combined with its long half-life and 100% bioavailability, allows once-daily anticoagulation without the need for monitoring activated clotting time. Subcutaneous fondaparinux was noninferior to enoxaparin treatment in patients with unstable angina or NSTEMI, and was more effective than usual care in those with STEMI. Fondaparinux has a favorable tolerability profile, particularly with regard to the risk of major bleeding, and limited data suggest that it is more cost effective than enoxaparin in the short term. Thus, overall, clinical evidence suggests that fondaparinux has a valuable place in the treatment of patients with ACS.

Fondaparinux: use in thromboprophylaxis of acute medical patients

Fondaparinux is a synthetic pentasaccharide that inhibits thrombin formation and thrombus development via selective antithrombin mediated inhibition of factor Xa. The complete bioavailability (100%) and elimination half-life of approximately 17 hours allows once-daily administration of fondaparinux. In a well designed trial (ARTEMIS) in acute medical patients aged > or = 60 years, fondaparinux was significantly more effective than placebo in terms of reducing the incidence of venous thromboembolism (VTE) up to day 15. The beneficial effect of fondaparinux therapy was observed in all subgroups of patients irrespective of underlying illness (e.g. acute heart failure or acute respiratory disease) in a predefined subgroup analysis of the ARTEMIS trial. Similarly, in a retrospective analysis of the trial, age and renal function did not appear to affect the incidence of VTE in fondaparinux and placebo recipients. Fondaparinux was generally well tolerated in this clinical trial. In patients receiving fondaparinux, the incidence of major bleeding was similar to that in patients receiving placebo and the incidence of minor bleeding was <3%.