Prolonged anticoagulant activity of rivaroxaban in a polymorbid elderly female with non-convulsive epileptic state.

OBJECTIVES AND BACKGROUND: Rivaroxaban, an oral direct factor Xa-inhibitor was non-inferior to adjusted dose warfarin in the prevention of stroke and embolism among patients with atrial fibrillation (AF) in the ROCKET-AF trial and has been approved for stroke prevention in AF.

CASE REPORT: A 88-years-old female (body-mass-index = 19.95) with AF, hypertension and diabetes mellitus, hospitalized because of heart failure and a non-convulsive epileptic state, was treated by valproate, mirtazepin, nebivolol, digitoxin, lisinopril, gliclazide and amlodipine. Irrespective of renal insufficiency, rivaroxaban 15 mg/d was started. After 3 days rivaroxaban was stopped because of concerns about the bleeding risk. Coagulation tests 28 h after rivaroxaban-intake showed INR 2.26, PT 35%, aPTT 38.3 s and anti-Factor Xa-activity 2.00 U/ml. Explanations for the prolonged anticoagulant activity of rivaroxaban comprise renal failure, the low body-mass-index, the advanced age and drug-drug interactions of rivaroxaban with mirtazepin, valproate and amlodipine.

CONCLUSION: Health care providers should consider renal function, concomitant medication, polymorbidity and age prior to prescribing rivaroxaban. Care has to be taken when prescribing rivaroxaban to patients who are different from those included in the ROCKET AF trial.