Crazy fast driver starts to joyride, eventually hospitalising us (4)
I believe the answer is:
jehu
'crazy fast driver' is the definition.
'starts to joyride eventually hospitalising us' is the wordplay.
'starts to' suggests taking the first letters.
The first letters of 'joyride eventually hospitalising us' is 'JEHU'.
(Other definitions for jehu that I've seen before include "OT king" , "fast driver" , "OT charioteer" , "Reckless driver" , "Ahab's successor" .)