Making Sense of Abbreviations

Once your doctor hands you a written prescription, it is likely that you will not be able to read it. Doctors and pharmacists speak to each other in a shorthand using Latin abbreviations. Here are some you may find:

ac = before meals
ad lib = at will
ad = right ear
as = left ear
bid = twice a day
cc = cubic centimeters
gtt = drop
hs = at bedtime
mEq = milliequivalents
mg = milligrams
mL = milliliters
od = right eye
os = left eye
pc = after meals
PO = by mouth
prn = as needed
qd = every day
qh = every hour
q4h = every 4 hours
qid = 4 times a day
tid = 3 times a day