American Board of Internal Medicine (ABIM) Certification Practice Exam

Which of the following is a contraindication for cilostazol?

1. History of stroke

2. Diabetes mellitus

3. Heart failure with ejection fraction below 40%

4. Chronic kidney disease

The correct answer is: Heart failure with ejection fraction below 40%

Cilostazol is a medication primarily used to treat symptoms of intermittent claudication in patients with peripheral arterial disease. It works by inhibiting phosphodiesterase type 3, leading to vasodilation and improved blood flow. However, there are specific contraindications associated with its use. The primary reason for the contraindication in patients with heart failure and an ejection fraction below 40% is that cilostazol can exacerbate heart failure symptoms. In patients with reduced ejection fraction, the ability of the heart to pump efficiently is already compromised. The additional vasodilatory effects of cilostazol can lead to decreased preload and worsening heart failure symptoms. Clinical studies have indicated that cilostazol may increase the risk of adverse cardiovascular events in hearts that are not functioning optimally. Hence, its use in this patient population is discouraged to prevent potential complications. In contrast, having a history of stroke, diabetes mellitus, or chronic kidney disease does not inherently contraindicate the use of cilostazol, although caution may be warranted in managing these conditions. Patients with a history of stroke might need additional monitoring for potential bleeding risks with concurrent medications. Diabetes mellitus can be managed alongside cilostazol, and chronic kidney disease may require dose adjustments but is not