Cilostazol is a medication that has been approved for the treatment of intermittent claudication, a condition that causes pain and cramping in the legs due to poor blood circulation. Cilostazol works by inhibiting an enzyme called phosphodiesterase III, which increases the levels of a molecule called cyclic adenosine monophosphate (cAMP) in the blood vessels. This leads to vasodilation, antiplatelet, and antiproliferative effects, which improve blood flow and oxygen delivery to the muscles1.
Besides intermittent claudication, cilostazol has been investigated for other potential uses in patients with vascular diseases, such as:
- Prevention of restenosis after coronary or peripheral endovascular interventions. Restenosis is the narrowing of a blood vessel after it has been opened by a procedure such as angioplasty or stenting. Cilostazol may prevent the growth of smooth muscle cells and the formation of blood clots that can cause restenosis2.
- Secondary prevention of stroke. Stroke is a serious condition that occurs when the blood supply to a part of the brain is interrupted, causing brain damage. Cilostazol may reduce the risk of recurrent stroke by preventing platelet aggregation and improving cerebral blood flow3.
- Treatment of cerebral small vessel disease. Cerebral small vessel disease is a disorder that affects the small arteries and capillaries in the brain, causing cognitive impairment, dementia, and stroke. Cilostazol may improve the symptoms and outcomes of this disease by enhancing nitric oxide production and reducing inflammation4.
However, the evidence for these uses is not conclusive and cilostazol is not approved for them by the FDA. More research is needed to confirm the efficacy and safety of cilostazol in these settings. Cilostazol may also have some side effects, such as headache, diarrhea, dizziness, and bleeding, and it may interact with other medications. Therefore, cilostazol should only be used under the guidance of a doctor.
Cilostazol and aspirin are both antiplatelet drugs that prevent blood clots from forming in the arteries. However, they have different mechanisms of action and effects on blood thinning. Cilostazol inhibits an enzyme called phosphodiesterase III, which increases the levels of a molecule called cyclic adenosine monophosphate (cAMP) in the blood vessels. This leads to vasodilation, antiplatelet, and antiproliferative effects, which improve blood flow and oxygen delivery to the muscles1. Aspirin inhibits an enzyme called cyclooxygenase, which reduces the production of a molecule called thromboxane A2, which promotes platelet aggregation and vasoconstriction.
According to some studies, cilostazol has a better blood thinning effect than aspirin, as measured by the inhibition of platelet aggregation and the prolongation of bleeding time. For example, a study by Kim et al. compared the effects of cilostazol and aspirin on platelet function and coagulation in patients with ischemic stroke. They found that cilostazol significantly inhibited platelet aggregation induced by adenosine diphosphate (ADP) and collagen, and significantly prolonged the bleeding time, compared to aspirin. Another study by Lee et al. compared the effects of cilostazol and aspirin on platelet aggregation and thromboelastography in patients with coronary artery disease. They found that cilostazol significantly inhibited platelet aggregation induced by ADP, arachidonic acid, and epinephrine, and significantly reduced the clot strength and elasticity, compared to aspirin.
However, the blood thinning effect of cilostazol may also increase the risk of bleeding, especially in combination with other anticoagulants or antiplatelet drugs. Therefore, cilostazol should be used with caution and under the guidance of a doctor.
