I have taken toprol for seven years. I never had any bad side effects and it controlled my blood pressure most of the time. However, I suffer from anxiety and depression and was recently put on Lexapro. My heart rate dropped into the 40's and I was exhausted all the time. Turns out Lexapro interacts with Toprol in that the drug (Toprol) does not break down in your system and keeps building up! Because the Lexapro was helping my anxiety I decided to lower the Toprol dosage. Down to 12.5 mg and still extremely low heart rate and fatigue. Decided to go off the Toprol and monitor my blood pressure, which has been amazingly good so far. Went off completely six days ago and it has been rough. Anxiety, insomnia, pounding heart, heart palpitations. This stuff is a real B*tch to get off from. Have talked to both the pharmacist and my doctor and both said to NOT start taking it again. There are plenty of newer medications out there. I also experienced weight gain when I first started taking it...I think because it slows your metabolism down. So now I am on xanax to counteract the Toprol until the Lexapro kicks in more. It it isn't one thing, it's another.