Drinks up: sot finally swallowed tablet (5)
I believe the answer is:
stela
'tablet' is the definition.
(I've seen this before)
'drinks up sot finally swallowed' is the wordplay.
'drinks' becomes 'ales' (ale is a kind of drink).
'up' shows that the letters should be reversed in order (in down clue: letters go upwards).
'finally' indicates one should take the final letters.
'swallowed' is an insertion indicator.
The final letter of 'sot' is 't'.
'ales' reversed gives 'sela'.
'sela' going around 't' is 'STELA'.
(Other definitions for stela that I've seen before include "People having digs" , "Ancient column" , "Stone tablet" , "Upright stone slab" , "Standing stone" .)