Patient Care Hematology & Oncology - October 2007 - (Page 11)

Bridge anticoagulation I outpatient use of enoxaparin and dalteparin in 515 patients.3 The most common indications for the use of OAC were mechanical valve replacement (n = 209), AF (n = 134), and stroke (n = 58). The procedures included general and urologic surgery and catheter insertion. Enoxaparin was used in a dosage of 1 mg/kg SC bid (n = 143), and dalteparin was used at 100 IU/kg SC bid (n = 372). LMWH was administered on an average of 5 times preoperatively, the last dose being no less than 12 hours preprocedure, and restarted 8 to 24 hours postprocedure and continued until concurrent warfarin achieved a therapeutic INR. Mean days without OAC were 6. There were no thrombotic complications. Two major episodes of bleeding and 17 minor bleeding events were reported. The authors suggested that LMWH administered SC in a fixed dose is an alternative to IV UFH when warfarin therapy is withheld. Patients with a history of HIT type II should receive neither UFH nor LMWH.7,8 There are no studies that evaluate the role of bridge therapy in this population. Direct thrombin inhibitors (DTIs) TABLE 2 or fondaparinux (Arixtra) are viable options for this population (see Table 2). The DTIs currently available in this country are lepirudin (Refludan), argatroban (Novastan), and bivalirudin (Angiomax), the last of which is approved solely for use in percutaneous cardiovascular interventions. Desirudin (Iprivask), not yet available in the United States, is indicated solely for DVT prophylaxis after hip surgery. DTIs are structurally different from heparin and do not cross-react with HIT antibodies. Their use requires hospitalization, since they are administered by IV infusion and monitoring of the aPTT is necessary to assure therapeutic levels. Although fondaparinux can be given as an SC injection with no monitoring required, its very long half-life (17-21 hours) precludes its use in the preoperative setting. Protocols for bridge therapy This section discusses protocols for bridge therapy with either UFH or LMWH. See Table 3 (page 12) and Table 4 (page 13) for sample schedules with these drugs. Continued on page 12 Dosing and monitoring of direct thrombin inhibitors and fondaparinux Dosing Monitoring Dosage adjustments LEPIRUDIN (REFLUDAN) 0.4 g/kg IV bolus, then 0.15 mg/kg/h 0.75-2.0 SC mg/kg q12h ARGATROBAN (NOVASTAN) 2 mcg/kg/min IV FONDAPARINUX (ARIXTRA) 7.5 mg SC q24h Key: aPTT, activated partial thromboplastin time. Source: Hassell K. The management of patients with heparin-induced thrombocytopenia who require anticoagulant therapy. Chest. 2005;127(2):1S-8S. aPTT Adjust in renal dysfunction aPTT Adjust in liver dysfunction None Adjust in renal dysfunction OCTOBER 2007 PATIENT CARE HEMATOLOGY & ONCOLOGY 11

Table of Contents Feed for the Digital Edition of Patient Care Hematology & Oncology - October 2007

Patient Care - Hematology & Oncology - October 2007 Research Digest Contents Information for Authors Medicine in the News Strategies for Bridge Anticoagulation Therapy How to Integrate the New Cervical Cancer Guidelines into Practice Dermatology Case Challenge Clinical Clips Classified Advertising

Patient Care Hematology & Oncology - October 2007

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.