I was diagnosed with adult ADHD after both of my boys were diagnosed. I was taking Adderall 10mg x 2 times a day. That didn't work for long, so he put me on 20mg for am and 10mg for pm. For the last couple of weeks, I've noticed that if I take my afternoon dose (and I don't always take it... just only if I feel like I need it and I rarely take it on my days off unless I have to drive) my heart will race and do what I call a "triple beat" and I'll lose my breath. At one time, due to finances, I couldn't fill my script for almost two weeks and a friend gave me a ritalin before I got into serious trouble at work. Within minutes, I was calm, relaxed so focused better than I ever have been. It was almost like taking a valium. Should I talk to my dr about changing?