Rogue nurse's cold treatment not satisfactory at first (9)
I believe the answer is:
scoundrel
'treatment not satisfactory at first' is the definition.
I can't tell whether this definition defines the answer.
'rogue nurse's cold' is the wordplay.
'rogue' is an anagram indicator (letters go rogue).
'nurse'+'cold'='nursecold'
'nursecold' anagrammed gives 'SCOUNDREL'.
(Other definitions for scoundrel that I've seen before include "Untrustworthy figure" , "Bounder" , "Rat" , "Knave" , "Disreputable type" .)