So illegal narcotics and the drug trade are a big part of my campaign world. Take a look at these rules and let me know what you think!
http://worldbuilderblog.me/2015/04/07/return-of-the-orange-spice/
I really like how you've taken the opportunity to world build. What would a world look like that was impacted by the discovery of this substance? Including careers related to it. Perhaps look into the impact on local law enforcement and legal codes.
Much better than my introduction of Cinorch-a weed (Chronic spelled backwards har har) that makes the consumer have a strong desire to consume food. 
I used it as a cure for the blindness caused by certain beasts (advanced glaucoma har har). You had to find it in the wilderness and there was almost always some hippie cleric dude hanging around to talk about how great it was "mannnnnn".
Keep up the great work!
Nice touch,
Once had 2 characters "addicted" to black-tabacco. A substance that had really no effect once taken, but after every 2 days of not smoking it it gave a -2 to CON with 1 being the lowest.
Gave a few plot hooks. Characters needed to steal more gold to finance there addiction, had to find dealers, had to stock up when going on an adventure and such.
Can be great to start an adventure with, but also a crime to have in the party...
I have a substance in my pirate campaign called Black Betel. It's a highly addictive variant of chewing tabacco, that turns the teeth of its users black, and causes teeth to rot. It is illegal in my campaign, but since the players are pirates, some smuggling is of course involved.
There might be trouble with the effects of that Orange Spice, Jimbo. The effect of it granting an extra action per round for an hour is extremely powerful. Not only is the positive effect worth the negative effect, but using this substance will change a difficult dungeon to a cakewalk. Are you sure you want 5th level fighters making 4 greatsword attack per turn and wizards lobbing two fireballs? And what if npc's start using it? The pc's breaking into his lair sounds like a good time for mr. ogre to start smoking and hitting like a giant.
I like the idea of a positive mechanical effect though, that'll certainly seduce players to use it faster than "euphoric feelings" or "nice hallucinations".
As to the negative effects, the players will have means to negate those. The poisoned condition is quite easy to cure. Even addiction is pretty easy to handle with a month of not touching the stuff.
I suggest toning down the positive effect (a lot).