I just got the shirt pocket edition of Pharmacopeioa and I'm kind of dissapointed. There's not much in there about the mechanism of action of drugs. I think it's probably more useful as a prescribing or dosing referencing for doctors and pharmacists, than as a tool to look up what drugs do for med students. I hear there's also a "Deluxe, Lab Coat" edition of this book. Is that any better?