Apixaban 5 mg ‘appropriate’ in AF patients with one dose-reduction criterion
medwireNews: The benefits of apixaban 5 mg over warfarin are maintained in patients with atrial fibrillation (AF) who are of advanced age, have low body weight or elevated creatinine levels, analysis of ARISTOTLE data shows.
This is despite these patients having a higher risk of bleeding and thromboemoblic events than patients with none of these characteristics.
The standard dose of apixaban in the ARISTOTLE (Apixaban for Reduction of Stroke and Other Thromboembolic Complications in Atrial Fibrillation) trial was 5 mg twice daily, explain John Alexander (Duke Clinical Research Institute, Durham, North Carolina, USA) and colleagues.
However, patients with at least two dose-reduction criteria, namely age 80 years or older, weight 60 kg or less or creatinine level at or above 1.5 mg/dL, received a reduced dose of 2.5 mg twice daily.
In the current study, Alexander and team investigated the effect of the 5 mg apixaban dose of patients with just one dose-reduction criterion.
They report in JAMA Cardiology that the 3966 patients with one dose-reduction criterion had significantly higher risks of stroke or systemic embolism (hazard ratio [HR]=1.47), ischaemic stroke (HR=1.54), major bleeding (HR=1.89), intracranial haemorrhage (HR=1.72), all-cause mortality (HR=2.01) and cardiovascular mortality (HR=1.88) than the 13,356 with no dose-reduction criteria.
In spite of this, apixaban’s superiority over warfarin in reducing the risk of stroke or systemic embolism was maintained, regardless of whether patients had one or no dose-reduction criteria, at respective hazard ratios of 0.94 and 0.77.
Similarly, patients with one or no dose-reduction criteria benefitted equally from a reduction in major bleeding with apixaban versus warfarin, at hazard ratios of 0.68 and 0.72, respectively.
“These findings, that the bleeding benefits are preserved with the 5 mg twice daily dose of apixaban in patients with only 1 dose-reduction criterion, suggest that this apixaban dose should be used in this population”, Alexander et al remark.
They add: “Patients should be treated with the effective doses as studied, because using the reduced 2.5 mg twice daily dose of apixaban in this population could result in preventable strokes.”
Editorialists Jeffrey Weitz and John Eikelboom, both from McMaster University in Hamilton, Ontario, Canada, echo this conclusion and express concern that despite less than 5% of ARISTOTLE patients having two or more dose reduction criteria, current global prescription data show that at least 25% of patients are receiving the lower apixaban dose.
They say: “Education is urgently needed to translate this information into practice because the inappropriate use of the lower dose of apixaban may place patients at risk for stroke.”
By Laura Cowen
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