My father is having 70% blockage in right carotid artery’s and 50% blockage in left carotid artery before 2 years he used to black out frequently. We consulted neurologist and after doing carotid doppler test, as per doctors advice. He is taking clopitab cv 10 since last 2 years and levera 500. After taking these medicine, he have never blacked out again. Recently we did the doppler test again and the report is still the same. No reduction in blockage. Could you please suggest what should we do to reduce the blockage.