a corps perdu
abruptly
bang
carelessly
dash
desperately
furiously
happen what may
hastily
head over heels
headfirst
headforemost
headlong
heedlessly
heels over head
helter-skelter
holus-bolus
hotfoot
hotheadedly
hurriedly
hurry-scurry
impulsively
like a flash
like a thunderbolt
like crazy
like mad
madly
of a sudden
on short notice
overeagerly
overenthusiastically
overzealously
plop
plump
plunk
pop
precipitantly
precipitately
precipitously
quickly
ramble-scramble
rashly
recklessly
sharp
slam-bang
slap
slap-bang
slapdash
smack
startlingly