This document contains abbreviations commonly used in medical prescriptions and documentation. It includes abbreviations for timing of medication administration, drug formulations, routes of administration, amounts, weights and measures. It also provides formulas for calculating dosages for children based on their age, weight or months for infants under 1 year old.

1. Mr. Manikandan.T,
RN., RM., M.Sc(N)., D.C.A .,(Ph.D)
Assistant Professor,
Dept. of Medical Surgical Nursing,
VMCON, Puducherry.

2. ABBREVIATION DERIVATION MEANING
a.c. Ante cibum Before meals
p.c. Post cibum After meals
a.m. Ante merediem Before noon
p.m. Post merediem After noon
Alt, die Alternis diebus Alternate days
o.m. Omni mane Each morning
o.d. Omni die Daily once
o.n. Omni note Each night
h.s. Hora somni At bed time
P.r.n Pro re nata When required
s.o.s Si opus sit If necessary in emergency
Abbreviation regarding time of administration

3. ABBREVIATION DERIVATION MEANING
b.d. Bis in die Twice a day
t.i.d Ter in die Three times a day
Stat. statim At once
q.i.d Quarter in die Four times a day
h hora hour
Cont.,

4. ABBREVIATION DERIVATION MEANING
Aq. aqua water
Dil. dilutis dilute
Fl. fluidium fluid
Inf. infusum infusion
Lin. linimentum liniment
Liq. liquer liquid
Lot. lotio lotion
Ol. oleum oil
Pulv. pulvis powder
Sp. spiritus Spirit
Syr. syrupus syrup
Abbreviation regarding the preparation of drug

5. Abbreviation regarding AMOUNT
ABBREVIATION DERIVATION
cc Cubic centimeter
gr grain
gtt A drop
m minim
kg kilogram
o A pint
Mg or mgm milligram
oz ounce
c with
s without
cm centimeter
Gm, g gram
ml milliliter
Garg. gargle

6. Abbreviation regarding AMOUNT
ABBREVIATION DERIVATION
l liter
gal gallon
tsp teaspoonful
dr dram
Meq milliequivalent
tab tablet
Cap,caps capsule
Dist. distilled
qt quart

7. Abbreviation regarding route
ABBREVIATION DERIVATION
AD Right ear
AS Left ear
AU Each ear
H hypodermic
IM Intramuscular
IV Intra venous
IVP Intravenous push
RX Treatment, prescription
OD Right eye
sc subcutaneously
SC Subcutaneous
OS Left eye
OU Both eyes
p or P after or per

8. Abbreviation regarding route
ABBREVIATION DERIVATION
Per os, PO By mouth
EC Enteric coated
elix elixir
Ext. External,extract
os mouth

9. ABBREVIATION MEANING TIME
Q4H Every 4 hours(6times) 8-12-4-8-12-4
Q6H Every 6 hours(4 times) 6-12-6-12
T.D.S Thrice a day 8-2-8
B.D. Twice a day 8-8
O.D. Once a day 8
H.S. At bed time 8
Q8H Every 8 hours 6-2-10
Alt h Alternate hours Every 3 hour
qh Every hour Every one hour
qod Every other day, noct night
Abbreviation regarding the preparation of drug

10. Weights and measures
unit Approximate value
1 dram 60 minim/ 60 grains/ 4gms/4ml(cc)/1 tsf/60 drops
1 ounce 30gm/ 30ml/ 2 tablespoon/8 teaspoonful/8 dram
1 litre 1000ml/ 40 ounces/2 pint/ 1 quart
1 gram 1000mg/ 15 grain/1,000,000mcg
1 grain 60 mg
1cc 1 ml/15minim
1 minim 1 drop/0.06ml
1 pint 20 0unce/500ml
1 pound 450 gm

11. Weights and measures
unit Approximate value
1 table spoon 4 dram/4 tsf/15ml/half ounce
1 teacupful 6 ounce/180ml
1 glassful 8 ounce/240ml
1 meter 40 inch/100cm/1000mm
1 cm 10mm
1 km 1000m/ 0.6 mile
1 foot 12 inch/30cm
1 inch 2.5 cm
1 ml 15 minim/60microdrop/15 macrodrop

12. Weights and measures
unit Approximate value
4 ml 1 fluid um
1 gallon 4liter/4000ml
1000gm 1kg/2.2 pound(lb)

13. Dosage calculation
Young’s rule(1-12 yrs)
age of child in years
Child dose= adult dose
age of child + 12

14. Dosage calculation
clark’s rule(weight)
weight of child in pounds
Child dose= adult dose
150

15. Dosage calculation
fried’s rule(under1 yr)
age of child in month
Child dose= adult dose
150

16. Dosage calculation
Intravenous drip
Total amount of fluid to be infused
Drop factor
Total time x 60 min
Drop factor = 15 drops/ min