The
low molecular weight heparin (
LMWH)
dalteparin sodium is notable for its improved pharmacokinetic characteristics (chiefly increased bioavailability and plasma elimination half-life) compared with
unfractionated heparin (UFH). These properties enable the
drug to be given subcutaneously as a single daily dose, compared with the 8- to 12-hourly regimens necessary with UFH.
Dalteparin sodium also appears to exert a greater inhibitory effect than UFH on plasma activity of
coagulation factor Xa relative to its effects on clotting times [usually expressed as activated partial thromboplastin time (APTT)] and activity of
factor IIa. It is not associated with any clinically significant effects on the fibrinolytic system and may have less lipolytic activity than UFH. Extensive clinical studies have been conducted to compare the antithrombotic efficacy of
dalteparin sodium with that of UFH in surgical thromboprophylaxis, treatment of established
deep vein thrombosis (DVT) and the anticoagulation of patients undergoing haemodialysis and haemofiltration. The majority of trails of patients receiving thromboprophylactic
heparin perioperatively have shown similar efficacy of
dalteparin sodium and UFH in the prevention of DVT and
pulmonary embolism (PE), although 2 groups of investigators reported superior antithrombotic potency for
dalteparin sodium. The two types of
heparin appear similarly effective in the management of established DVT and the maintenance of the
extracorporeal circulation in haemodialysis circuits.
Dalteparin sodium has also shown clinical benefit in the management of patients with
unstable angina or non-Q-wave
myocardial infarction. The overall incidence of haemorrhagic complications observed with daltparin
sodium therapy is no greater than that associated with UFH, and data suggest that perioperative transfusion requirements and frequency of
bleeding are lower after
dalteparin sodium. The antithrombotic efficacy of
dalteparin sodium is at least equivalent to that of UFH, although further clinical comparisons with other LMWHs are required. Further studies are also needed to clearly define any advantages of
dalteparin sodium over UFH (and other antithrombotics) with regard to the incidence of haemorrhagic complications. The
drug has also shown clinical efficacy in the prevention of
myocardial infarction and death in patients with unstable
coronary artery disease. In addition, there may be cost advantages attached to the once-daily subcutaneous regimen of
dalteparin sodium, but this requires further examination. Thus,
dalteparin sodium is an effective
antithrombotic agent for perioperative thromboprophylaxis, the management of established DVT, and the anticoagulation of patients undergoing haemodialysis.