S Coe's rival, bolstered by medicine, went very quickly (8)

'went very quickly' is the definition.
I can't tell whether this definition defines the answer.

's coe's rival bolstered by medicine' is the wordplay.
I cannot really understand how this works, but
's' is within the answer.
'medicine' could be 'med' (as in the informal term 'meds') and 'med' is found in the answer.
The remaining letters 'cram' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?