In terms of drug use nobody beats Afghanistan and Iran in the entire Muslim world.
ISIS/Al-QAEDA are trash like the Irani regime sponsored terrorist militias. Both sides are a stain on anything to do with Arabs or Iran.
Camp Speicher massacre was wrong, as was Talibans killing of Iranian diplomats etc. And the numerous Al-Assad regime (Shabiha in particular) regime crimes.
As for Captagon, your Iranian "Arab" Mullah regime's greatest regional (and oldest) allies (Al-Assad regime - now gone permanently) and Hezbollah are the masterminds of the Captagon trade. This has been confirmed already. All Captagon drugs that enter neighboring Arab countries (KSA, Iraq, Egypt,) all origin from Syria and Southern Lebanon. Recently KSA executed 10 drug smugglers from Egypt, Lebanon and Syria. All captured with tons of captagon pills.
So this trade was run by the Al-Assad family and Hezbollah.