Drug used in game turned up in sweet (8)
I believe the answer is:
lollipop
'sweet' is the definition.
(lollipop is a kind of sweet)
'drug used in game turned up' is the wordplay.
'drug' becomes 'pill' (drug taken as a pill).
'used in' indicates putting letters inside.
'game' becomes 'pool' (pool is a kind of game).
'turned up' is a reversal indicator.
'pill' inserted inside 'pool' is 'popillol'.
'popillol' backwards is 'LOLLIPOP'.
'in' is the link.
(Other definitions for lollipop that I've seen before include "Boiled sweet" , "Sweetmeat" , "Sweet; popular work" , "Confectionery" , "Ice confection" .)