A formal survey of dextromethorphan users[REF] showed that more than half of users reported experience of the following withdrawal-symptoms individually for the first week after long-term/addictive dextromethorphan use: fatigue, apathy, flashbacks, and constipation.
Misuse of multi-symptom cold medications, rather than using a cough suppressant whose sole active ingredient is dextromethorphan, carries significant risk of fatality or serious illness.