Current dosing of low-molecular-weight heparins does not reflect licensed product labels: an international survey.
OBJECTIVE
Low-molecular-weight heparins (LMWHs) are used globally to treat thromboembolic diseases; however, there is much debate on how to prescribe effectively for patients who have renal impairment and/or obesity. We aimed to investigate the strategies used to dose-individualize LMWH therapy.


METHODS
We conducted an online survey of selected hospitals in Australia, New Zealand (NZ), United Kingdom (UK) and the United States (US). Outcome measures included: the percentage of hospitals which recommended that LMWHs were prescribed according to the product label (PL), the percentage of hospitals that dose-individualized LMWHs outside the PL based on renal function, body weight and anti-Xa activity and a summary of methods used to dose-individualize therapy.


RESULTS
A total of 257 surveys were suitable for analysis: 84 (33%) from Australia, 79 (31%) from the UK, 73 (28%) from the US and 21 (8%) from NZ. Formal dosing protocols were used in 207 (81%) hospitals, of which 198 (96%) did not adhere to the PL. Of these 198 hospitals, 175 (87%) preferred to dose-individualize based on renal function, 128 (62%) on body weight and 48 (23%) by monitoring anti-Xa activity. All three of these variables were used in 29 (14%) hospitals, 98 (47%) used two variables and 71 (34%) used only one variable.


CONCLUSIONS
Dose-individualization strategies for LMWHs, which contravene the PL, were present in 96% of surveyed hospitals. Common individualization methods included dose-capping, use of lean body size descriptors to calculate renal function and the starting dose, followed by post dose anti-Xa monitoring.
Barras
Michael A
MA
School of Pharmacy, The University of Queensland, Brisbane, Queensland, Australia.
Kirkpatrick
Carl M J
CM
Green
Bruce
B
D000925:Anticoagulants / Q000008:administration & dosage*; D001315:Australia; D001835:Body Weight; D004334:Drug Administration Schedule; D054796:Drug Dosage Calculations; D004348:Drug Labeling; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage*; D006801:Humans; D009520:New Zealand; D009765:Obesity / Q000150:complications; D051437:Renal Insufficiency / Q000150:complications; D013923:Thromboembolism / Q000188:drug therapy*; D006113:United Kingdom; D014481:United States
D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight