What the American pharmacist has in store (5)

I believe the answer is:
drugs
'has in store' is the definition.
'drugs' can be an answer for 'has' (drugging is a kind of having). I am not sure about the 'in store' bit.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for drugs that I've seen before include "Medication" , "Narcotics" .)
