Many patients find that they must try different drugs to find the best one to treat their symptoms and minimze side-effects..... everyone seems to react differently..
Calcium channel blockers are also not without their side-effects. In my case, my ankles swelled up and my cardiologist had to put me on a diuretic. Others I know have complained about being tired, joint pain, coughing, upset stomach and constipation. But many have no problems whatsoever. It's like a roll of the dice.
Good luck!
consult your doctor.. If the side effects of the toprol are bothersome, he/she will likely switch you to a calcium channel blocker.