* The anticoagulant rivaroxaban (Xarelto) is now approved for stroke prophylaxis in patients with nonvalvular atrial fibrillation.
* Two boxed warnings are on rivaroxaban's label: stopping the drug increases the risk of stroke, and epidural or spinal hematomas are possible if the patient undergoes spinal puncture or receives neuraxial anesthesia.
* Like all anticoagulants, rivaroxaban can cause bleeding.
Diane S. Aschenbrenner is the course coordinator for undergraduate pharmacology at Johns Hopkins University School of Nursing in Baltimore, MD. She also coordinates Drug Watch: email@example.com.