Low Molecular Weight Heparins (LMWHs) are commonly used anticoagulants for the prevention and treatment of venous thromboembolism (VTE). LMWHs are high-risk drugs with a narrow therapeutic window, that are cleared renally.
Consensus has been reached on how LMWHs should be dosed for prophylactic use and for therapeutic use in the ‘standard’ patient. However, there is uncertainty about whether or not renally impaired patients should be treated with therapeutically dosed LMWHs and with which dosing regimen. For example, some guidelines recommend the use of unfractioned heparin (UFH) [1-6], whereas others state that LMWHs are safer and more effective than UFH [7-9].
Guidelines vary in their advice on dosing strategies of LMWHs and the usefulness of anti-Xa monitoring in patients with renal impairment. Some guidelines advise to apply a dose reduction [1,2,10], whereas others do not [3-6]. Moreover, some guidelines advise to apply dose adjustments based on anti-Xa activity [3-6], whereas others advise not to or to be very cautious with anti-Xa dose adjustments due to a lack of evidence [1,2,10].
To this end, the Dutch Society of Hospital Pharmacy (NVZA) has conducted a survey to identify how patients with renal impairment are currently being treated with LMWHs. In 59 Dutch hospitals, the treatment policies turned out to be very diverse [data not yet published]. This raised the question whether these differences also exist at a European level. We would like to study this by means of this survey and kindly ask you to respond.
Contact
Prof. Karina Meijer, k.meijer@umcg.nl
Tessa Jaspers, PharmD, PhD candidate, t.jaspers@etz.nl