The abuse of dextromethorphan

Q1) Talk about the abuse of dextromethorphan

Lets talk about the current issues with:
Loperamide-
Coricidin HBP
Ranitadine Zantac Recall
and how about this: https://www.empr.com/home/news/methemoglobinemia-f…

Q2) Lots of clinical debate about this- what is the difference and what do you think (Read and use PDF attachment to answer this question)