a.c.
before meals
p.c.
after meals
ad. lib.
as desired, freely
p.r.n.
when necessary
stat
immediately, at once
asap
as soon as possible
b.i.d.
twice a day
t.i.d.
3 times a day
q.i.d.
4 times a day
min
minute
h
hour
q.h
every hour
q.2h
every 2 hours
q.3h
every 3 hours
q.4h
every 4 hours
q.6h
every 6 hours
q.8h
every 8 hours
q.12h
every 12 hours