I, too, take this med. I have tolerated it quite well. I never had any of the side effects. Follow ireneo's advice and google the name of the med and read about it.
Cardizem (aka Diltiazem) is a calcium channel blocker, good for high BP, angina and some arrhythmia problems. I take it and it does a decent job of controlling my atrial tachy and chest pains. Also helpful for people with Raynauds.
Best thing is to google the name of the medication and you'll find out all kinds of info: how it's used, side effects, etc.
Except for a few side effects at the beginning (throbbing headache for the first couple of weeks, fatigue and mild dizziness) I adjusted quite well to it. I did not do well with Verapamil, also a CCB. See how this works for you but don't be discouraged if you feel funky for a couple weeks. It takes time for the body to adjust.