Moan endlessly about tablets for hearing and breathing problem? (8)
I believe the answer is:
wheezing
'breathing problem?' is the definition.
'moan endlessly about tablets for' is the wordplay.
'moan' becomes 'whinge' (I've seen this before).
'endlessly' means to remove the last letter.
'about' is an insertion indicator.
'tablets for' becomes 'eez' (I can't explain this - if you can you should give a lot more credence to this answer).
'whinge' with its last letter removed is 'whing'.
'whing' enclosing 'eez' is 'WHEEZING'.
'hearing and' acts as a link.
This may not be right. Some or all of it may be part of another bit of the clue.
(Other definitions for wheezing that I've seen before include "Breathing with difficulty" , "Breathing noisily" .)