I have taken KLOR-CON 10MEQ ER Tablets for several. During the holidays I needed the prescription refilled. My doctor was away, so his stand-in replaced KLOR-CON with POTASSIUM CL MICRO 10MEQ ER Tablets. Is there a difference in the generic version of potassium? I have noticed a side effect that I never experienced before, intermittent pain and weakness in my arms and shoulders. I suspect that potassium I am getting might be the cause.