Ive been taking opiate medication, ive been having palpitations?! anyone ever experienced this?

Im 27, male, medium build, i take opiate medication, and have never in my life had heart problems, ever. I started taking my meds about 9 months ago, and before i took them i never had any problems. about 3 months ago i started experiencing heart palpitations out of the blue. i was not doing any physical stress, or anything. almost feels like my eyes are kinda teary sometimes. well, i didnt know what to do, i didnt get any chest pains or anything, so i took some advice and took magnesium and potium. they stopped. well after about 3 weeks of taking potium, the palps went away. well here we are about 9 months later, and out of the blue, the palps started up again. i took a potium pill and they went away for the night. the next morning, they came back. I had a infected tooth this time and was gonna start taking penicillin that day (penicillin VK has potium in it) and the penicillin made them go away, i figured because of the potium that was in the penicillin. Ive cut back alot on the salts ( i dont even use it anymore on food) and i dont eat too much junk. I thought it might be because of the tooth infection, but im not too sure, i did notice when i have a bad tooth ache, i get heart palpitations from the pain. Now, ive never had them before, i dont know what it could be, it doesnt seem to be anything serious at least it doesnt feel like it. I get constipation from the meds, but it doesnt get too bad, and i dont get dizzy or light headed. when i lay down it doesnt get worse or change really. Im thinking it might be low sodium, or a potium deficency. but how long would i have to take potassium to get my levels back up? ive never had this problem till i took the medication, but it doesnt make sense, because opiates arent supposed to cause palpations. anyone with a similiar story? ive looked all over to see what the cause was and im desperate for some answer. Id really appreciate someone to take the time and really help me. Everytime ive told the doctor about it, he brushes it off and says everything is fine with my heart. I do have to say that i do have bad anxiety and panic attacks, but most of the time when it happens my anxiety is not even around. is it an adrenaline thing? any ideas? any suggestions as far as something i could do to pin point the reason? its getting annoying, and my doctor is a old quack, lol he is oldschool, im really healthy and have no other symptoms besides my hearing is some what off and i have a few bad teeth, other then that im as healthy as an ox. please help! thank you i appreciate it so much.!