Which of the following is the main advantage of this drug over the standard unfractionated heparin?
A 67-year-old woman was admitted to the hospital because of a progressive swelling and soreness of the left calf. After physical examination and lab exams, a diagnosis of deep venous thrombosis was made and a treatment with enoxaparin was started.
A. Complete absence of bleeding complications B. Good oral bioavailability C. Lower incidence of drug-induced thrombocytopenia
D. Pronounced antiplatelet activity E. Inhibitions of a larger number of coagulation factors
Lower incidence of drug-induced thrombocytopenia
-learning objective: describe the main advantages of lmwhs over standard heparin. answer: c
hmwh causes transient thrombocytopenia in up to 15% of patients and severe
thrombocytopenia (which is antibody-mediated) in up to 5% of patients. lmwhs-induced
thrombocytopenia is < 1%.
a) lmwhs cause a lower incidence of bleeding complications, which could be related to the fact
that these agents preferentially inhibit factor xa more potently than they inhibit thrombin
(thrombin inhibition requires a larger heparin molecule). nevertheless bleeding complications do
occur even with lmwh.
b) the oral bioavailability of both hmw and lmw heparins is zero.
d, e) lmwhs do not have antiplatelet activity and they actually inhibit less coagulation factors
than standard heparin.