Author/Editor		Poredoš, Pavel
Title		Prednosti nizkomolekularnega heparina pred standardnim heparinom
Translated title		Advantages of low-molecular-weight heparin in comparison with unfractionated heparin
Type		članek
Source		Med Razgl
Vol. and No.		Letnik 41, št. Suppl 1
Publication year		2002
Volume		str. 73-8
Language		slo
Abstract		Standard - unfractionated heparin (UFH), that until now was used as the only drug in the treatment of acute thrombotic events, exhibits various disadvantages. The most important of these are: an unpredictable anticoagulant effect that depends on binding of the drug to blood proteins, bleeding, thrombocytopenia and osteopenia. Low-molecular-weight heparin (LWMH) is produced by hydrolytic or enzymatic cleavage of UFH. Its anticoagulant effect is predominantly based on inactivation of factor Xa, but its effect on thrombin (IIa) is minimal. In comparison to UFH, pharmacokinetic and related pharmacodynamic properties of LMWH are significantly different. LMWH binds to a much lesser extent to plasma proteins, endothelial cells and macrophages. Consequently, the anticoagulation response of LMWH is more predictable and is closely related to the dosage of the drug. Further, clearance of LMWH is diminished and its half-life prolonged; therefore, a therapeutic effect is achieved by once-daily administration of the drug. Side effects such as thrombocytopenia and osteoporosis appear in patients treated with LMWH less often than in those treated with UFH. Recent studies show that LMWH is a safe and effective drug for prevention and treatment of venous thromboembolism, acute pulmonary embolism and for early treatment of patients with stable angina. Therefore, we conclude that LMWH is at least as effective and safe as UFH.
Summary		Nefrakcionirani heparin, ki se je do nedavnega uporabljal kot edino zdravilno sredstvo za preprečevanje in zdravljenje akutnih trombemboličnih zapletov, ima več pomanjkljivosti. Med najpomembnejše sodijo: ozka terapevtska širina, nepredvidljiv antikoagulacijski učinek, ki je odvisen od stopnje vezave zdravila na beljakovine v plazmi, krvavitve, pojavljanje trombocitopenije in osteopenije. Novejši nizkomolekularni heparin, ki ga pridobivajo iz nefrakcioniranega heparina s hidrolitično ali encimsko razgradnjo molekule, ima določene prednosti. Antikoagulacijski učinek nizkomolekularnega heparina temelji predvsem na zaviralnem delovanju aktiviranega faktorja X, na trombin (faktor II) se veže v omejenem obsegu, zato ga tudi ne inaktivira. Nizkomolekularni heparin ima v primerjavi z nefrakcioniranim heparinom spremenjene farmakokinetične lastnosti, ki pomembno vplivajo na farmakodinamiko zdravila. V znatno manjšem obsegu se veže na beljakovine v plazmi, na endotelijske celice in makrofage. To ima za posledico povsem predvidljiv antikoagulacijski učinek, ki je neposredno odvisen od odmerka zdravila, počasi se izloča iz telesa, kar pomembno podaljša razpolovno dobo zdravila in omogoča učinkovito zdravljenje z enim samim dnevnim odmerkom zdravila. Manj pogosti pa so tudi zapleti, kot sta trombocitopenija in osteopenija. Dosedanje raziskave so pokazale, da je nizkomolekularni heparin varno in učinkovito zdravilo za preprečevanje in zdravljenje venske tromboze, za zdravljenje pljučne trombembolije in nestabilne angine pektoris. Zato menimo, da je nizkomolekularni heparin varno in najmanj toliko ali še bolj učinkovito zdravilo za zdravljenje trombemboličnih bolezni kot standardni heparin.
Descriptors		THROMBOPHLEBITIS HEPARIN HEPARIN, LOW-MOLECULAR-WEIGHT ANGINA, UNSTABLE