Information on daughter, drugged (5)
I believe the answer is:
doped
'drugged' is the definition.
('doped' can be a synonym of 'drugged')
'information on daughter' is the wordplay.
'information' becomes 'dope' (dope is a kind of information**).
'on' means one lot of letters go next to another.
'daughter' becomes 'd'.
'dope'+'d'='DOPED'
(Other definitions for doped that I've seen before include "Under the influence of narcotics" , "Nobbled" , "Drugged" .)