Miranda Davies 1, 2, Alison Evans 1,2, Flavien Coukan 1, 2, Lesley Wise1, Saad Shakir 1,2

Affiliations: 1 Drug Safety Research Unit, 2 University of Portsmouth

Background

Rivaroxaban is used to treat patients with non-valvular AF for the prevention of stroke and systemic embolism. This requires a fixed daily dose (20mg) with dosage reduction only recommended in patients with a reduced creatinine clearance (15-49 ml/min), a range encompassed within chronic kidney disease (CKD) stage 3-4 (eGFR 15-59) although CKD 3a (eGFR 45-59) is largely outside this range. Rivaroxaban is not recommended in patients with severe renal impairment (creatinine clearance < 15 ml/min).

Objectives

To assess starting dose amongst patients with chronic kidney disease stage 3-4 or 5.

Methods

The ROSE study was a specialist cohort event monitoring study of patients prescribed rivaroxaban. Specialists provided information via detailed questionnaires at baseline (and ≥ 12weeks). Baseline characteristics included starting dose and presence of either CKD stage 3-4 (eGFR 15-59) or CKD stage 5 (eGFR < 15). Starting dose was examined amongst patients with CKD stage 3-4 and 5 to assess how many patients had a reduced starting dose of less than 20mg od.

Results

The cohort consisted of 965 patients with AF: 75 patients with history of either stage 3-4 CKD (n=73, 7.6%) or stage 5 CKD (n=2, 0.2%). Of the patients with CKD stage 3-4, 36 (49.3 %) were started on <20 mg daily (15mg od [n=35]; 10mg od [n=1]). 35 patients (48.0 %) were started on ≥ 20mg (20mg od [n=34]; 30mg od [n=1]). Starting dose was missing for two patients (2.7%). Neither patient with CKD stage 5 had a dose reduction.

Conclusion

Our results suggest that amongst patients with CKD stage 3-4, approximately half were started on the recommended reduced dose of < 20mg od. Not all patients with CKD stage 3-4 would be recommended a dose reduction as per the product label. A UK audit suggests that approximately 20% of patients in the UK with CKD 3 are 3b rather than 3a although the frequency may be higher in a hospital cohort.