Spontaneous hemothorax caused by concomitant low-dose rivaroxaban and itraconazole in a 95-year-old patient: case report and literature review.

Although direct-acting oral anticoagulants (DOACs) decrease the bleeding risk compared with vitamin K antagonists (VKAs), DOACs might cause spontaneous hemothorax in very elderly patients, even at a very low dose. Interactions between drugs might increase the risk of bleeding. In this article, we report a case of a 95-year-old man who developed spontaneous hemothorax while taking rivaroxaban 2.5 mg twice daily, 3 days after concomitant use of itraconazole. Rivaroxaban was discontinued, and thoracentesis was performed to drain grossly bloody pleural effusion. To our knowledge, this is the first case report of spontaneous hemothorax that might have been caused by concomitant low-dose rivaroxaban and azole anti-fungal agents. This case highlights the potential risk of spontaneous hemothorax in very elderly patients while taking rivaroxaban and azole anti-fungal agents simultaneously. Special attention should be paid to interactions between drugs that might increase the risk of bleeding. Drugs that have competing metabolic pathways should be avoided. Closer monitoring, including testing for anti-Xa and additional reassessment, should be considered in high-risk patients.