Pharmacy Abbreviations (NAPLEX, PTCB, ExCPT)

Sig abbreviations are shorthand notations commonly used in prescriptions and medical orders to convey essential instructions to patients, healthcare providers, pharmacists and pharmacy technicians.

These abbreviations are critical for improving communication, efficiency, and safety in the medication dispensing process. They are typically derived from Latin and are used to describe dosage, frequency, route of administration, and other key instructions on how a medication should be used.

Time & Frequency

Abbreviation	Meaning	Sig Example
q	Every	Take 1 tablet q6h (every 6 hours)
qAM	Every morning	Take 1 tablet qAM
qPM	Every evening	Take 1 tablet qPM
qhs	Every night at bedtime	Take 1 capsule qhs
qam	Every morning	Take 1 tab qam with food
qod	Every other day	Take 1 tablet qod
qd or q.d.*	Once daily	Take 1 tab qd
bid or b.i.d.	Twice daily	Take 1 tab bid
tid or t.i.d.	Three times daily	Take 1 capsule tid
qid or q.i.d.	Four times daily	Apply ointment qid
q4h	Every 4 hours	Take 2 tablets q4h
q6h	Every 6 hours	Take 1 capsule q6h
q8h	Every 8 hours	Take 1 tab q8h
q12h	Every 12 hours	Take 1 tab q12h
stat	Immediately	Take 1 tablet stat for chest pain
prn	As needed	Take 1 tab prn for pain
q__h prn	Every __ hours as needed	Take 1 tab q6h prn for headache
ac	Before meals	Take 1 capsule ac
pc	After meals	Take 1 capsule pc
hs	At bedtime	Take 1 tablet hs
ud	As directed	Use 1 puff ud
qwk	Every week	Take 1 tablet qwk
biw	Twice a week	Take 1 capsule biw
tiw	Three times a week	Take 1 tablet tiw
qh	Every hour	Instill 1 drop qh in left eye
sig	Directions	–

Route of Administration

Abbreviation	Meaning	Sig Example
i.d.	Intradermal	Inject 0.1 mL i.d. once for TB test
IM	Intramuscular	Inject 1 mL IM every 12 hours
IV	Intravenous	Administer 500 mL IV over 1 hour
PO	By mouth (oral)	Take 1 tablet PO twice daily
SC or SQ or SubQ	Subcutaneous	Inject 10 units SC before meals
Inj	Injection	Inj 1 mL SC daily

Ear-Related

Sig abbreviations related to the ear (otic administration), which are commonly used in pharmacy practice. These abbreviations are derived from Latin terms and are used to indicate how and where medications should be applied to the ear(s).

Abbreviation	Meaning	Sig Example
gtt	Drop	Instill 1 gtt in affected ear tid
gtts	Drops	Instill 3 gtts in affected ear bid
Otic	For the ear	Apply otic drops as directed
AD	Right ear (auris dextra)	Instill 3 drops in AD twice daily
AS	Left ear (auris sinistra)	Instill 2 drops in AS at bedtime
AU	Both ears (auris utraque)	Instill 4 drops in AU every 8 hours

Eye-Related (Ophthalmic)

Common eye-related sig abbreviations used in prescriptions for ophthalmic (eye) medications.

Abbreviation	Meaning	Sig Example
gtt or gtts	Drop(s)	Instill 1 gtt in affected eye q8 hours
OD	Right eye (oculus dexter)	Instill 1 drop OD twice daily
OS	Left eye (oculus sinister)	Instill 1 drop OS at bedtime
OU	Both eyes (oculi uterque)	Instill 2 drops OU every 4 hours

Dosage Form

Abbreviation	Meaning (Dosage Form)	Sig Example
cap	Capsule	Take 1 cap PO daily
tab	Tablet	Take 1 tab PO twice daily
gtt	Drop(s)	Instill 2 gtt in each eye twice daily
supp	Suppository	Insert 1 supp rectally at bedtime
sol	Solution	Take 10 mL of sol PO every 8 hours
susp	Suspension	Shake well and take 1 tsp of susp PO twice daily
elix	Elixir	Take 2 tsp of elix PO every 6 hours
syr	Syrup	Take 5 mL of syr PO three times a day
ung	Ointment	Apply a thin layer of ung to affected area daily
crm	Cream	Apply crm to rash BID
lot	Lotion	Apply lot to skin twice a day
soln	Solution (topical/oral)	Rinse mouth with 10 mL of soln and spit
inhal	Inhaler	Inhale 2 puffs via inhal every 4 hours PRN
MDI	Metered Dose Inhaler	Use 1 puff via MDI every 6 hours
neb	Nebulizer solution	Neb 1 vial QID
troche	Lozenge	Dissolve 1 troche in mouth TID
patch	Transdermal Patch	Apply 1 patch to skin every 72 hours
pwd	Powder	Apply powder to feet daily
spr	Spray	Spr 2 sprays into each nostril once daily
film	Oral film (e.g., buccal)	Place 1 film on tongue once daily
inj	Injection	Inj 1 mL SC every morning
liq	Liquid	Take 10 mL of liq PO once daily
chew tab	Chewable Tablet	Chew 1 chew tab after meals
ODT	Orally Disintegrating Tab	Place 1 ODT on tongue and allow to dissolve

Allergy and Condition Abbreviations

Abbreviation	Meaning	Sig Example
NKDA	No Known Drug Allergies	Pt reports NKDA in EHR.
NKA	No Known Allergies	Allergies: NKA.
PCN	Penicillin	Allergy: PCN – causes rash.
ASA	Acetylsalicylic Acid (Aspirin)	Avoid ASA due to GI bleeding.
HTN	Hypertension	Take 1 tab PO QD for HTN.
DM	Diabetes Mellitus	Monitor glucose BID for DM.
CHF	Congestive Heart Failure	Take 40 mg furosemide PO QAM for CHF.
COPD	Chronic Obstructive Pulmonary Disease	Use inhaler QID PRN for COPD symptoms.
CAD	Coronary Artery Disease	Take atorvastatin HS for CAD.

Dry Weight Units

Abbreviation	Unit	Equivalent	Sig Example
mcg	Microgram	1 mcg = 0.001mg	Give 400 mcg PO once daily
mg	Milligram	1 mg = 1,000mcg	Take 500 mg PO BID
g or gm	Gram	1 g = 1,000mg	Take 1 g PO daily
kg	Kilogram	1 kg = 1,000g	Dose: 10 mg/kg body weight
gr	Grain	1 grain ≈ 65 mg	Take 1 gr tablet TID (rare/old use)
oz (avoirdupois)	Ounce (weight)	1 oz = 28.35g	Apply 1 oz ointment to affected area
lb	Pound	1 lb = 16 oz = 453.6g	Pediatric dose based on 20 lb weight
dr or ʒ	Dram	1 dram ≈ 1/16 oz ≈ 1.77g	Mix 1 dr into 100 mL of water

Liquid Weight Units

Abbreviation	Meaning	Metric Equivalent	Sig Example
gtt(s)	Drop(s)	Varies (commonly ~0.05 mL)	Instill 2 gtt in each eye QID
mL	Milliliter	1 mL = 1 cc	Take 5 mL PO every 6 hours
cc	Cubic centimeter	1 cc = 1 mL	Inject 1 cc IM once daily
tsp	Teaspoon	1 tsp = 5 mL	Take 1 tsp PO TID
tbsp	Tablespoon	1 tbsp = 15 mL	Take 1 tbsp PO BID
oz	Ounce	1 oz = 30 mL	Drink 1 oz PO at bedtime
fl oz	Fluid ounce	1 fl oz = 30 mL	Take 2 fl oz PO every 4 hours
pt	Pint	1 pt = 473 mL	Drink 1 pt water after prep
qt	Quart	1 qt = 946 mL	Take 1 qt prep night before procedure
gal	Gallon	1 gal = 3,785 mL	Take 1 gal of prep solution over 4 hours
L	Liter	1 L = 1,000 mL	Drink 1 L of oral rehydration solution daily

Source

Lab Test Abbreviations (Medical Abbreviations)

Abbreviation	Meaning	Example
ABG	Arterial Blood Gas	Order ABG to assess blood pH, oxygen, and CO2 levels
CBC	Complete Blood Count	CBC with differential, check for WBC, RBC, platelets
CMP	Comprehensive Metabolic Panel	CMP to evaluate glucose, electrolytes, liver, and kidney function
BMP	Basic Metabolic Panel	BMP to assess blood glucose, calcium, and kidney function
LFT	Liver Function Tests	LFT to check enzymes like AST, ALT, bilirubin levels
PT	Prothrombin Time	PT to assess blood clotting (INR calculation)
INR	International Normalized Ratio	INR to monitor warfarin therapy
PTT	Partial Thromboplastin Time	PTT for clotting disorders or to monitor heparin therapy
HGB	Hemoglobin	HGB level is measured for anemia or blood disorders
HCT	Hematocrit	HCT to determine the percentage of red blood cells
WBC	White Blood Cells	WBC count is assessed in infection or immune response
RBC	Red Blood Cells	RBC count is evaluated in anemia or blood loss
PLT	Platelet Count	PLT is assessed for bleeding disorders or bone marrow function
BUN	Blood Urea Nitrogen	BUN to assess kidney function
Cr	Creatinine	Serum Cr to evaluate renal function
TSH	Thyroid Stimulating Hormone	TSH to evaluate thyroid function
T4	Thyroxine	Free T4 to assess thyroid function
T3	Triiodothyronine	T3 to assess thyroid function
HBA1C	Hemoglobin A1C	HBA1C for long-term blood glucose control in diabetes
FBS	Fasting Blood Sugar	FBS to check for diabetes or blood sugar management
OGTT	Oral Glucose Tolerance Test	OGTT to diagnose diabetes or prediabetes
Lipid Panel	Lipid Profile	Lipid panel to assess cholesterol, LDL, HDL, and triglycerides
CRP	C-Reactive Protein	CRP to measure inflammation in the body
ESR	Erythrocyte Sedimentation Rate	ESR to detect inflammation or infection
U/A	Urinalysis	U/A to detect urinary tract infections, kidney function
C&S	Culture and Sensitivity	C&S to determine the infecting organism and its drug sensitivity
D-dimer	D-dimer Test	D-dimer to rule out blood clots or deep vein thrombosis
Amylase	Amylase	Amylase to evaluate pancreatitis or digestive disorders
Lipase	Lipase	Lipase to check for pancreas inflammation
A1AT	Alpha-1 Antitrypsin	A1AT to assess genetic risk for lung diseases (e.g., emphysema)
TIBC	Total Iron Binding Capacity	TIBC to assess iron levels in the blood
Uric Acid	Uric Acid	Uric Acid test to evaluate gout or kidney stones

Benefits of Pharmacy Abbreviations for Pharmacy Professionals (NAPLEX, PTCB, ExCPT)

For pharmacy professionals, sig abbreviations are invaluable as they provide a standardized, concise way to convey instructions that would otherwise require lengthy descriptions. This reduces the potential for errors related to misinterpretation and helps speed up the prescription process.

For example, “PO” (per os) indicates the medication should be taken orally, and “BID” (bis in die) means twice daily. These shorthand notations save time while ensuring consistency across healthcare settings.

In addition, sig abbreviations help prevent medication errors by promoting clear, unambiguous instructions. Pharmacists, technicians, and clinicians are all trained in the same set of abbreviations, which minimizes confusion when interpreting medical orders. Moreover, accurate sigs ensure that the right dose is taken at the right time, improving patient adherence and treatment outcomes.