Background and importance International guidelines vary in their advice whether or not to reduce the therapeutic dose of low molecular weight heparins (LMWHs) in renal impairment. The use of anti-Xa monitoring as a basis of dose adjustments is also a matter of debate.

Aim and objectives To study the nationwide treatment policies of therapeutically dosed LMWHs in renal impairment in hospitals.

Material and methods An 11-item survey was distributed to clinical pharmacists nationwide between June 2020 and March 2021. Primary outcome was the hospital dosing regimen for therapeutically dosed LMWHs in renally impaired patients. Secondary outcomes were the proportion of hospitals that used anti-Xa monitoring and the anti-Xa target range used. Descriptive statistics were used to analyse the data.

Results The survey was completed by 56 of the 69 (81%) hospital organisations nationwide. Of the included hospitals, 91% applied a fixed-dose reduction at the start of the LMWH treatment in renally impaired patients (71% reduced if estimated glomerular filtration rate (eGFR) <50 mL/min and 20% if eGFR <30 mL/min). The majority (64%) of hospitals applied a dose reduction of 25% if eGFR is 30–50 mL/min and of 50% if eGFR is <30 mL/min. Anti-Xa levels were not routinely monitored in renally impaired patients in 43% of hospitals, while 20% of hospitals monitored anti-Xa if eGFR <50 mL/min, 25% if eGFR <30 mL/min and 12% with other eGFR cut-off values. Target ranges of 1.0–2.0 IU/mL (once-daily dosing) and 0.5/0.6–1.0 IU/mL (twice-daily dosing) were used in 69% of hospitals that monitored anti-Xa.

The most commonly applied treatment regimen was dose reduction if eGFR <50 mL/min without anti-Xa monitoring, regardless of the type of LMWH.

Conclusion and relevance This study demonstrates substantial nationwide diversity in the treatment policies of therapeutically dosed LMWHs in renally impaired patients in hospitals. The most commonly used treatment regimen in hospitals is to apply a fixed dose reduction if eGFR is <50 mL/min, without anti-Xa monitoring. This treatment regimen is not yet described in LMWH treatment guidelines in renally impaired patients and should be explored in future research.

Conflict of interest No conflict of interest