I can't find the Commandment that says, "Thou shalt not smoke pot - but alcohol is OK."
Drunkenness, the state of being intoxicated, that's what the Bible exhorts against.
By "drunk" are you using the ordinary secular meaning, which excludes moderate effect (such as 'relaxation')? If so, then use of other drugs to that degree is likewise not contrary to the Bible.
Or if you include any degree of effect in "drunk," then should the "bigger stick" of government appealed to by the original poster be brought to bear against being to any degree affected by alcohol?