The GameMastery Guide introduces rules for drugs. Among other things, it specifically states that drugs can be created via a Craft: Alchemy check. However, it fails to list a craft DC for any of them.
What's the craft DC? Should I assume it is equal to the addiction DC (just like poisons)?
Drugs can be manufactured using Craft (alchemy). The DC to make a drug is equal to its addiction DC. Rolling a natural 1 on a Craft skill check while making a drug exposes the crafter to the drug.
I hope he figured it out before 3.5 years went by.