Molecular Weight Heparins

Substances other than enzymes can be immobilized. Examples include the fixing of heparin on polytetrafluoroethylene with the aid of PEI (424), the controUed release of pesticides which are bound to PEI (425), and the inhibition of herbicide suspensions by addition of PEI (426). The uptake of anionic dyes by fabric or paper is improved if the paper is first catonized with PEI (427). In addition, PEI is able to absorb odorizing substances such as fatty acids and aldehydes. Because of its high molecular weight, PEI can be used in cosmetics and body care products, as weU as in industrial elimination of odors, such as the improvement of ambient air quaHty in sewage treatment plants (428). 

Hirsh J, Warkentin TE, Shaughnessy SG et al (2001) Heparin and low-molecular-weight heparin mechanisms of action, pharmacokinetics, dosing, monitoring, efficacy, and safety. Chest 119(Suppl.) 64S-94S... 

Fractionated Heparins Low-Molecular- Weight Heparins (IMWHs) ... 

Polysaccharides can regulate weak interactions between protein molecules. A recent example is the effect of low molecular weight heparin molecules on the weak dimerisation of the plasminogen growth factor NKl, or at least a mutant thereof [135]. 

Iron dextran injection contains a complex of iron hydroxide with dextrans of average molecular weight between 5000 and 7000, and is used for the treatment of iron-defieiency anaemia in situations where oral therapy is ineffeetive or impractical. The sodium salt of sulphurie aeid esters of dextran, i.e. dextran sodium sulphate, has anti-eoagulant properties eomparable with heparin and is formulated as an injection for intravenous use. 

The multiple effects of UFH on the coagulation cascade may increase its potential to cause hemorrhage." Anticoagulants with more specific sites of action may confer a better safety profile. Two such anticoagulants are low-molecular-weight heparin (LMWH) and heparinoids. 

FIGURE 7.2 LMWH inhibits factor Xa and minimally affects factor Ha thus, activated partial thromboplastin time is not used to measure its anticoagulant activity. (Reprinted from the American Family Physician published by the American Academy of Family Physicians, February 15th, 1999, in an article entitled Low-molecular-weight heparin in outpatient treatment of DVT. )... 

For patients with Acute Ischemic Stroke they recommend clinicians not to use full-dose anticoagulation with IV, subcutaneous, or low-molecular-weight heparins or heparinoids (grade 2B evidence). 

There is no recommendation for general use of heparin, low-molecular-weight heparin, or heparinoids after ischemic stroke (Level of Evidence I). 

Administration of low-dose heparin or low-molecular-weight heparin in an equivalent dose is always recommended in bedridden patients to reduce the risk of DVT and PE (Level of Evidence II). 

Gordon DL, Linhardt R, Adams HP. Low molecular-weight heparins and heparinoids and their use in acute or progressing ischemic stroke. Clin Neuropharmacol 1990 13 522-543. 

Bath P, Iddenden R, Bath F. Low-molecular-weight heparins and heparinoids in acute ischemic stroke, a meta-analysis of randomised controlled trials. Stroke 2000 31 1770-1778. 

Berge E, Abdelnoor M, Nakstad PH, Sandset PM, on behalf of the Haest Study Group. Low molecular-weight heparin versus aspirin in patients with acute ischemic stroke and atrial fibrillation a double blind randomised study. Lancet 2000 335 1205-1210. 

Sandercock P, Counsell C, Stobbs SL. Low-molecular-weight heparins or Heparinoids versus standard Unfractionated heparin for acute ischemic stroke (Review). The Cochrane Collaboration 2006. 

Miklautz, H., Riemann, J., and Vidic, H. J., The molecular weight distribution of heparin determined with a HPLC-LALLS technique, /. Liq. Chromatogr., 9, 2073, 1986. 

Low molecular weight heparins (adjust dose for renal dysfunction [i.e., creatinine clearance <30 mL/min])... 

All patients with a mechanical prosthetic heart valve should receive concomitant unfractionated heparin or a low molecular weight heparin in combination with warfarin pharmacotherapy until the INR is therapeutic and stable for two consecutive days... 

Low molecular weight heparins (adjust doses for renal dysfunction)... 

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