Hi, I was put on clopidogrel 75 mg, labetalol 200 mg and amlodipine besylate 5mg after the placement of a stent one year ago. When I exert myself, I experience shortness of breath. I have had many tests including EKG, Ultrasound, stress test and all come back in the normal range. Can one of these drugs be causing the shortness of breath? Thank you, Wally