CONTEMPORARY USE OF AND FUTURE ROLES FOR HEPARIN IN ANTITHROMBOTIC THERAPY

Although heparin therapy is an established component of the prevention and treatment of thromboembolic disease, recent advances have resulte d in improvements in the clinical use of this agent. Studies have show n that weight-based dosing influences significantly both the time to r each a therapeutic intensity of anticoagulation and the incidence of t hromboembolic recurrence. It is now considered the standard of care. A growing understanding of the variability among activated partial thro mboplastin time (aPTT) reagents and the influence of these differences on aPTT outcomes has led to the use of reagent-specific therapeutic r anges for heparin monitoring. Many practitioners now choose to adjust the therapeutic range to correspond to heparin serum concentrations of 0.2-0.4 U/mL rather than the more common practice of prolonging aPTT to 1.5-2.5 times the mean normal aPTT. Pharmaceutical companies have d eveloped low molecular weight heparins to minimize adverse effects ass ociated with unfractionated heparin. More specific thrombin inhibitors are also under investigation with the aim of improving clinical outco mes in coronary syndromes now treated with heparin. Low molecular weig ht heparins or specific thrombin inhibitors are unlikely to replace un fractionated heparin in the near future. Therefore, optimum dosing and appropriate monitoring of heparin are critically important in the man agement of thromboembolic disease.