A young rookie cop responds to noise complaint that turns sour when the offender turns out to be a mentally disturbed drug addict that forces him to take a drug that allows him to see demons.

I think this sounds really interesting. I love stories like this where you have a normal guy that gets thrown into a situation. I was going to give critique, but patrockable said everything I had to say. This sounds really cool though.

Sorry, I meant "demon revealing"

You're welcome, glad I could help!

The "stop being able to see demons" goal sounds to me like a "refusual of the call" reaction, I'd say the main action would be to fight the demons and save the world, so this would be better for your logline.

Also, maybe "demon world revealing" drug might better suggest that the demons were always there?

So something like:

When a deranged addict forces a rookie cop to take a "demon revealing" drug, he must destroy the demons to save the world. :)

It reads like the way in which the demons are discovered and released are less important rather what is important is the cop fighting demons.

Maybe try and use the victory over demons as the goal and the discovery regardless its device the II:
"When a young cop discovers a portal for demons in a drug addicted mental patient he must fight to stop the demons coming through whilst under the influence of drugs himself."

Patrockable is correct ;)

" I assumed the demons always existed, and the drug just activates a dormant Sixth Sense?, allowing the user to see this supernatural world."

You would be correct :)