Dextromethorphan
"Took my first dose last night before bed since I have been having a nagging cough from allergies. Helped suppress the cough a little (not completely) but I was up on and off all night with anxiety, nausea, night sweats, and of course, coughing. It is now 2pm the following day and I have been extremely dizzy all day and have been having very gassy diarrhea and stomach cramps. I have been stuck at home all day feeling bad. Will never use this medication again. I prefer coughing over vertigo and diarrhea."