Mixed Antagonist of Serotonin for Claudication Optimal Therapy

Inclusion Criteria: * 1\. Patient with stable symptoms of intermittent claudication of the lower extremities, secondary to chronic occlusive arterial disease from atherosclerosis origin (symptoms present for 6 months or longer and not significantly changed within the past 3 months); * 2\. ICD of 30 to 200 m at screening constant workload treadmill test * 3\. Doppler-measured pre-treadmill ABI of 0.90 or lower after 10 minutes of rest or, for patients with an ABI of greater than 1.3 (non-compressible arteries), a Toe-Brachial Index (TBI) of less than 0.7. Exclusion Criteria: * 1\. Age below 40 years and/or onset of symptoms of PAD before the age of 40 years; * 2\. Non-atherosclerotic vascular disease (e.g. Buerger's disease, popliteal entrapment syndrome); * 3\. Limb-threatening (grades III and IV) chronic limb ischemia, manifested by ischemic rest pain, ulceration, or gangrene. * 4\. Patients with a history of malignant or proliferate breast disease.