If i am taking a mucinexdm pill can i also take an over-the-counter cough syrup? just want to make sure they r safe together

Perhaps: The cough suppressant in Mucinex (guaifenesin) dm is dextromethorfan. It is ralatively mild cough suppressant and ofter combined with an anti-histamine. I'm not sure what other cough medicine you want to use. Codeine often works better and is available by prescription. If the cough is persistant you probably should see your physician.