Nursing Math Academy ยท Module 1
Medical Abbreviations & SIG Codes
Learn common routes, frequencies, timing instructions, dosage forms, and medication safety abbreviations. This is the first module in a series building nursing medication-math fluency.
Lesson 1
Abbreviation Library
Search or filter by category. Flagged (โ ๏ธ) abbreviations are error-prone.
By mouth (oral)
from per os
Example: Ibuprofen 400 mg PO q6h PRN pain
๐ก P.O. = Pop it Orally
Sublingual (under the tongue)
from sub lingua
Example: Nitroglycerin 0.4 mg SL q5min ร 3 PRN chest pain
Per rectum (rectally)
from per rectum
Example: Acetaminophen 650 mg PR q6h PRN fever
Intravenous
from intra venam
Example: Normal saline 0.9% 1 L IV over 1 hour
Intramuscular
from intra musculum
Example: Ceftriaxone 1 g IM ร 1
Subcutaneous
from sub cutis
Example: Enoxaparin 40 mg SubQ daily
๐ก Avoid 'SQ' โ can be misread as '5Q' or '5 every'
Intradermal
Example: Tuberculin 0.1 mL ID (Mantoux test)
Nasogastric tube
Example: Metoclopramide 10 mg NG q6h
Percutaneous endoscopic gastrostomy
Example: Levothyroxine 100 mcg PEG daily on empty stomach
By inhalation
Example: Albuterol 2 puffs INH q4h PRN wheeze
Topically (on the skin)
Example: Hydrocortisone 1% TOP BID to affected area
Transdermal (through the skin)
Example: Fentanyl 25 mcg/hr TD patch q72h
Once daily
from quaque die
Example: Write 'daily' โ 'QD' may be read as 'QID' (four times daily)
Twice daily
from bis in die
Example: Metoprolol 25 mg PO BID
Three times daily
from ter in die
Example: Amoxicillin 500 mg PO TID ร 10 days
Four times daily
from quater in die
Example: Ondansetron 4 mg PO QID PRN nausea
Every other day
Example: Write 'every other day' โ 'QOD' can be misread as 'QD' or 'QID'
Every hour
from quaque hora
Every 2, 4, 6, or 8 hours
Example: Morphine 2 mg IV q4h PRN pain
As needed
from pro re nata
Example: Acetaminophen 650 mg PO q6h PRN pain โ always requires an indication
Immediately
from statim
Example: Furosemide 40 mg IV STAT
At bedtime
from hora somni
Example: Consider spelling 'at bedtime' โ 'HS' can be confused with 'half-strength'
Before meals
from ante cibum
Example: Regular insulin 4 units SubQ AC
After meals
from post cibum
Morning
from ante meridiem
Evening
from post meridiem
Nothing by mouth
from nil per os
Example: NPO after midnight prior to procedure
As desired / freely
from ad libitum
Tablet
Capsule
Suspension (shake before use)
Solution
Syrup
Suppository
Ointment
from unguentum
Sustained-, extended-, or extended-release โ do not crush
Example: Metoprolol succinate ER 50 mg PO daily โ swallow whole
Right eye
from oculus dexter
Example: Confusable with 'overdose' โ write 'right eye'
Left eye
from oculus sinister
Both eyes
from oculus uterque
Right ear
from auris dextra
Example: Write 'right ear' โ 'AD' has been confused with 'right eye'
Left ear
from auris sinistra
Both ears
from auris utraque
With
from cum
Without
from sine
Drop(s)
from gutta
Example: Latanoprost 1 gtt OU qHS
Of each (equal parts)
from ana
Dispense
Example: Disp: #30 tablets
Directions for the patient (label as)
from signa
Example: Sig: 1 tab PO BID
Prescription / take
from recipe
Educational use only. Always follow your organization's approved abbreviation policy and verify unclear medication orders before administration.