Suboxone generally speaking doesn't cause too many issue for the chronic user, however, if you have taken them long enough, any change in your dosing
schedule can cause problems, because, like rawwwr said above, Suboxone
causes a VERY severe withdrawal for most people trying to discontinue them. Therefore, it is entirely possible that the Suboxone contributed to the panic attacks the first time.
Problem with anxiety and panic is that they cause a cycle of anxiety.