"fainting spell. about 30 minutes after taking this, for about 15 minutes my heart would race (~135bpm?), and i would feel as if i were about to faint (head rush?). i would spend 15 minutes trying to remain calm, fighting the urge to collapse. i tried it twice and had the same response. thank goodness i wasn&#039;t driving when it kicked in. my wife had a similar reaction. seriously, please be cautious when first trying this medication."