Dextromethorphan hydrobromide--what should i expect for "side effects?

I tell patients: To expect no side effects.....However dextromethorphan can cause drowsiness. More significant side effects include anxiety, slowed breathing, hallucinations all of which require attention. Hopefully it will also suppress a cough which is usually why it is prescribed. www.drugs.com has a lot of good information if you want to check it out.