Similar to q.a.m.

o_2 - both eyes, sometimes written as o2
p.c. - post cibum - after meals
p.m. - post meridiem - evening or afternoon
p.o. - per os - by mouth or orally
p.r. - per rectum - by rectum
per - per - by or through
pig./pigm. - pigmentum - paint

View all in Prescription