tussionex is a prescription cough suppressant. while taking tussionex you should not have the need for another cough suppressant so i would avoid mucinex dm. if your cough is loose and productive you can take plain mucinex with the tussionex which will help break up the phlegm and not interact with your tussionex.
my doctor gave me tussionex suspension. can i take mucinex dm with it at the same time?