Still unwell at home, visited by nurse giving drug (10)
I believe the answer is:
penicillin
'drug' is the definition.
(penicillin is a kind of drug)
'still unwell at home visited by nurse' is the wordplay.
'still' becomes 'pic' (short for picture).
'unwell' becomes 'ill' (similar in meaning).
'at home' becomes 'in' ('I'm in' can mean 'I'm at home').
'visited by' indicates putting letters inside.
'nurse' becomes 'EN' (abbreviation for enrolled nurse).
'pic'+'ill'+'in'='picillin'
'picillin' going around 'en' is 'PENICILLIN'.
'giving' acts as a link.
(Other definitions for penicillin that I've seen before include "Common antibiotic" , "17" .)