Heparins

Heparins boost antithrombin, which inactivates thrombin and factor Xa, preventing new clots and stopping existing clots from growing. Unfractionated heparin is given IV or by injection under the skin and is monitored with aPTT or anti-Xa levels, while low molecular weight heparins such as enoxaparin are injected at fixed doses. Bleeding and heparin-induced thrombocytopenia, a dangerous drop in platelets, are the major risks. Protamine sulfate fully reverses unfractionated heparin and partially reverses enoxaparin.

• EnoxaparinKnown brand names include Lovenox.
• Heparin (unfractionated)Known brand names include No current brand name; marketed as generic heparin sodium injection.