Sick notes in disrepute (3,4)
I believe the answer is:
ill fame
'disrepute' is the definition.
(I've seen this before)
'sick notes' is the wordplay.
'sick' becomes 'ill' ('ill' can be a synonym of 'sick').
'notes' becomes 'fame' (note can mean attention or regard**).
'ill'+'fame'='ILL-FAME'
'in' is the link.
(Other definitions for ill fame that I've seen before include "Disrepute" , "notoriety" , "bad report" , "A house of . . . . . . . is a brothel" , "celebrity of sorts" .)