Intervened, having cold, given drug (9)
I believe the answer is:
medicated
'intervened having cold' is the definition.
I can't tell whether this defines the answer.
'drug' is the wordplay.
I cannot quite see how this works, but
'drug' could be 'medicate' (I've seen this before) and 'medicate' is present in the answer.
A single letter 'd' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'given' is the link.
Can you help me to learn more?
(Another definition for medicated that I've seen is " Like some shampoos".)