Abbreviations used in prescriptions:

• a.c. (ante cibum) – before meals
• ad lib. (ad libitum) – use as much as one desires; freely
• alt. h. (alternis horis) – every other hour
• c (cibos) – food
• D.A.W. – dispense as written
• dc, D/C, disc – discontinue
• e.m.p. (ex modo prescripto) – as directed
• ex aq – in water
• h.s. (hora somni) – at bedtime
• L.A.S. – label as such
• N.K.A. – no known allergies
• noct. (nocte) – at night
• NPO, n.p.o. (non per os) – nothing by mouth
• p.c. (post cibum) – after meals
• p.o. (per os) – by mouth or orally
• s.a. (secundum artum) – use your judgement
• sig – write on label
• s.o.s., si op. sit (si opus sit) – if there is a need

Napoleon Bonaparte described medicine as “a collection of uncertain prescriptions the results of which, taken collectively, are more fatal than useful to mankind.”