Thrice weekly warfarin administration in haemodialysis patients.
BACKGROUND
Medication adherence in haemodialysis patients is often challenging due to a high pill burden, complex and dynamic medication regimens and limited patient self-interest in care. The purpose of this study was to investigate the time within target INR and safety profile of thrice weekly warfarin administration in haemodialysis patients with a clinical indication for anticoagulation and documented nonadherence to medications.


METHODS
Thirty-seven patients from two haemodialysis units in Winnipeg, Manitoba, Canada, were recruited, and 17 patients were treated with thrice weekly warfarin and compared to 20 patients treated with daily warfarin therapy. The patients were followed for 1 year with weekly international normalized ratio (INR), dosage and adverse events recorded. The primary outcome was percentage of time with INR in target and sub (<1.5)- and supra (>4)-therapeutic INR. Adverse events were recorded in the two groups.


RESULTS
The thrice weekly group had a higher burden of comorbidity (Charlson comorbidity index of 6.35 +/- 1.77 versus 4.55 +/- 1.64, P = 0.003) compared to the daily dosage group. In the thrice weekly dosage group, time within target INR was higher (56.9 versus 49.3%, P = 0.008), and time with supra-therapeutic INR > 4 lower (2.7 versus 4.3%, P = 0.03). Total bleeding events (7 versus 6) and major bleeding events (3 versus 2 events) were similar between the two groups.


CONCLUSIONS
In this pilot study, thrice weekly warfarin appears to be a safe and feasible dosing strategy in a select patient population. A randomized controlled trial of thrice weekly warfarin is warranted.
Sood
Manish M
MM
Boniface General Hospital, University of Manitoba, Winnipeg, Manitoba, Canada. msood@sbgh.mb.ca
Rigatto
Claudio
C
Bueti
Joe
J
Lang
Cory
C
Miller
Lisa
L
PonnamPalam
Arjuna
A
Reslerova
Martina
M
Sood
Amy
A
Komenda
Paul
P
D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage*; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D010865:Pilot Projects; D006435:Renal Dialysis; D014859:Warfarin / Q000008:administration & dosage*
D000925:Anticoagulants; D014859:Warfarin