American Board of Internal Medicine (ABIM) Certification Practice Exam

For patients with ischemic stroke who are on aspirin, what is the recommended additional medication for secondary prevention?

1. Clopidogrel

2. Dipyridamole

3. Warfarin

4. Statins

The correct answer is: Dipyridamole

In patients with ischemic stroke who are already on aspirin, adding dipyridamole is a recommended strategy for secondary prevention. This recommendation arises from clinical studies indicating that the combination of aspirin and dipyridamole is more effective than aspirin alone in reducing the risk of recurrent strokes. Dipyridamole works by inhibiting platelet aggregation and has vasodilatory properties, which complement aspirin's action. While clopidogrel is another antiplatelet medication that could be beneficial, it is more frequently considered in cases where a patient is intolerant to aspirin or where there is a specific indication such as acute coronary syndrome. Additionally, warfarin, an anticoagulant, is typically reserved for patients with certain conditions, such as atrial fibrillation or certain types of thrombophilia, rather than being the standard choice for most ischemic stroke patients. Lastly, statins are primarily used for their cholesterol-lowering effects and the reduction of cardiovascular risk but do not have the same direct role in preventing recurrent ischemic strokes in patients already on aspirin. Therefore, the combination of aspirin and dipyridamole provides a well-supported approach for effective secondary prevention of strokes.