[3] Because it can be given subcutaneously and does not require APTT monitoring, LMWH permits outpatient treatment of conditions such as deep vein thrombosis or pulmonary embolism that previously mandated inpatient hospitalization for unfractionated heparin administration.

[5] As compared to placebo or no intervention, prophylactic treatment of hospitalized medical patients using LMWH and similar anticoagulants reduces the risk of venous thromboembolism, notably pulmonary embolism.

[10] The CLOT study, published in 2003, showed that dalteparin was more effective in patients with malignancy and acute venous thromboembolism than warfarin in reducing the risk of recurrent embolic events.

[11] The use of LMWH in cancer patients for at least the first 3 to 6 months of long-term treatment is recommended in numerous guidelines and is now regarded as a standard of care.

LMWHs depend more on renal function for their excretion than unfractionated heparin, so their biological half-life may be prolonged in patients with kidney failure.

HIT Type II is caused by the formation of autoantibodies that recognize complexes between heparin and platelet factor 4 (PF4) and is, therefore, associated with a substantial risk of thrombotic complications.

[9] Animal and in vitro studies have demonstrated that protamine neutralizes the antithrombin activity of LMWHs, normalizing the aPTT and thrombin time.

As a result, patients with risks, such as the severely obese or in advanced stages of kidney failure, show decreased benefits due to fractionated heparin's increased half-life.

The coagulation cascade is a normal physiological process to prevent significant blood loss or hemorrhage following vascular injury.

For instance, some high-risk conditions, such as prolonged immobilization, surgery, or cancer, can increase the risk of developing a blood clot, which can potentially lead to significant consequences.

[2] These are listed below: Deaminative cleavage with nitrous acid forms an unnatural anhydromannose residue at the reducing terminal of the oligosaccharides produced.

Likewise, chemical and enzymatic beta-elimination results in an unnatural unsaturated uronate residue (UA) at the non-reducing terminal, as shown in figure 2.

These quality assurance steps, to be effective, need to be implemented from the raw material (crude heparin) collection to the final LMWH product.

Due to these identified and potential differences, several organizations, including the United States Food and Drug Administration, the European Medicines Agency, and the World Health Organization, regard LMWHs as individual products that should not be considered clinically equivalent, as they differ in many crucial aspects such as molecular, structural, physiochemical, and biological properties.

The FDA has used five analytical and pharmacological criteria to establish the authenticity of a generic LMWH without requiring clinical studies in patients.

[27] From a regulatory viewpoint, the FDA considers LMWHs (as well as insulin, glucagon and somatropin) as "generic" drugs, even though they may be sourced from biological material.

The European Medicines Agency considers LMWH biologicals, so their regulatory approval – as biosimilars – is approached differently than the FDA's.