Will Not use dextromethorphan and guaifenesin When you are using or For those who have utilised an MAO inhibitor prior to now 14 times. A unsafe drug interaction could happen. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, and tranylcypromine. It's not a complete list of Dextromethorphandrug interactions. Check https://apothekedrogen.eu/