Amlodipine
"Worst drug I've ever tried and the reason I'm scared of new drugs.
It made me have tachycardia. My heart was speeding at over 200 bpm sitting still. Worse if I got up to walk around or anything like that. I couldn't sleep because it felt like I was running. I would stay in bed propped up (because laying down made it worse) and occasionally drift off when I got so exhausted I couldn't stay awake anymore. This sleep only lasted about an hour at a time before I woke up again. Docs increased the dose saying I just needed to get used to it. It made it worse. I made them take me off of it after "giving it a try" for three hellish weeks."