gal or gals = gallons g = gram
O, pt or pts = pints kg = kilogram (1,000g)
oz or ozs = ounces mg = milligram (1/1,000g)
fl.oz = fluid ounces mcg or µg = microgram (1/1,000,000g)
lb or lbs = pounds L or l = litre (or liter in US)
st = stones cl = centilitre (1/100 L)
gtts = drops ml = millilitre (1/1000 L)
iu = international units µl = microlitre (1/1,000,000 L)
m or min = minims meq or mEq = Milliequivalent
hr = hour m = metre (or meter in US)
min = minutes mm = millimetre (1/1,000 m)
sec = seconds cc or cu.cm = cubic centimetres (1/1,000 L)
ft = foot or feet dr = dram or drachm
gr = grains sc = scruple
t or tsp = teaspoon T or tbsp = tablespoon
Of General Interest
&S226; One litre of pure water weighs approx. one kilogram so 1cc of water weighs 1 gram.
&S226; A steel paper clip weighs about 1 gram.
&S226; "A spoonful" means heaped or rounded, with as much above the bowl of the spoon as in the spoon. Obviously, a measure of liquid is a level spoonful.
Liquid Metric Conversions
1 gallon (gal)(US) = 3785 ml 1 gallon (UK) = 4546 ml
1 pint (pt)(US) = 473.18 ml 1 pint (UK) = 568.26 ml
16 fluid ounces (US) = 473.18 ml 20 fluid ounces (UK) = 568.26 ml
8 fluid ounces (US) = 236.59 ml 10 fluid ounces (UK) = 284.13 ml
4 fluid ounces (US) = 118.29 ml 5 fluid ounces (UK) = 142.07 ml
1 fluid ounce (fl.oz)(US) = 29.57 ml 1 fluid ounce (UK) = 28.41 ml
- - - -
1cc = 1g = 1ml (approx) 1 teaspoon = 5 ml (approx)
10 minims = 0.616 ml 1 tablespoon = 15 ml (approx)
15 to 16 drops ( gtts ) = 1 cc = 1ml 1 drop = 1 minim approx
Note:- Spoon and drop conversions should be regarded as approximations due to the different surface tensions and specific gravity of various liquids.
Solid Metric Conversions
1 pound (avoirdupois) = 453.592 g 1/2 grain = 30 mg
1 pound (apothecary) = 373.242 g 1/4 grain = 15 mg
1 ounce (avoirdupois) = 28.35 g 1/8 grain = 8 mg
1 ounce (apothecary) = 31.10 g 1/12 grain = 5 mg
15 grains = 1 g 1/100 grain = 600 mcg
10 grains = 600 mg 1/150 grain = 400 mcg
7 1/2 grains = 500 mg 1/200 grain = 300 mcg
5 grains = 300 mg 1/250 grain = 250 mcg
1 1/2 grains = 100 mg 1/300 grain = 200 mcg
1 grain = 64.79891 mg 1 kilogram = 2.2 pounds
1 pound = 0.45 kilograms (kg) 1 stone = 6.35 kg
1000 mcg = 300 to 7000 iu (below) 1000 mcg = 1 mg
1 scruple = 1.2 g 1 drachm = 28.8 g
Note on International Units ( i.u. )
An old measurement of vitamin activity determined by biological methods as opposed to new measures that are determined by direct chemical analysis.
Many health foods and supplements still use i.u. ( IU ).
For Vitamin A, 1 i.u. = 0.3µg retinol, 3.6µg b-carotene, or 7.2µg other vitamin A carotenoids
For Vitamin D, 1 i.u. = 0.025µg cholecalciferol
For Vitamin E, 1 i.u. = 0.67µg natural a-tocopherol (different conversion factors are used for different forms of vitamin E)
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Ratios and Percent Solutions
1:100 = 1g/100ml [10mg/ml] = 1%
1:200 = 500mg/100ml [5mg/ml] = 0.5%
1:1,000 = 100mg/100ml [1mg/ml] = 0.1%
1:5,000 = 20mg/100ml [200mcg/ml] = 0.02%
1:10,000 = 10mg/100ml [100mcg/ml] = 0.01%
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Calculation of Milliequivalents (mEq)
mEq = Weight (grams) / mEq Weight (grams)
Ion or Compound mEq W.(g) Ion or Compound mEq W.(g)
Na+ 0.023 HC03- 0.061
K+ 0.039 NaCl 0.0585
Ca++ 0.020 KCl 0.0745
Mg++ 0.012 CaCl.2H2O 0.0735
NH4+ 0.018 NH4Cl 0.0535
Cl 0.0355 MgSO4.7H20 0.123
Lactate 0.089 NaHCO3 0.084
Acetate 0.059 Ca Gluconate 0.224
Citrate 0.063 Phosphorus 0.031
For milliequivalent weights not shown, use the formula:-
milliequivalent weight (mEq W.) = Atomic Weight (g) / (Valence) x 1,000
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Drug Administration Times
Standardised medication administration times should be followed as much as possible. The following table shows those hours of the day which are to be used as standardised times of medication administration. If the prescriber wishes the first dose to be administered before the earliest available standardised time then the prescriber should state "expedite" or "first dose now" with the drug order.
In ICU's the first dose of a newly ordered parenteral antibiotic regimen should be administered within 2 hours unless specified otherwise by the prescriber.
Ordered Time Hour(s) to be given
QAM 08
QD 08
QHS 21
QPM 17
BID 08 17
Q12H 08 20
Q8H 08 16 24
TID 08 12 17
TID AC 07 12 17
TID W/M 0730 1230 1730
QID 08 12 17 21
Q6H 06 12 18 24
AC & HS 07 12 17 21
PC & HS 08 13 18 21
1 HR AC & HS 0630 1130 1630 2100
1 HR PC & HS 0830 1330 1830 2100
5 X's/day 06 1030 15 1930 23
Q4H 04 08 12 16 20 24
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Common Terms and Abbreviations
Term or Phrase Abbreviation Meaning
ad ad to, up to
ad libitum ad. lib. at pleasure
ana a.a. of each
ante cibos a.c. before meals
aqua aq. water
bis in die b.i.d. twice a day
collyrium collyr. eye lotion
cum c. with
cum aqua cum aq. with water
dentur tales doses d.t.d. give such doses
dispensa disp. dispense
et et and
gutta, guttae gtt. drop, drops
hora somni h.s. at bedtime
in vitro in vit. in glass
misce m. mix
non repetatur non. rep. do not repeat
oculus dexter o.d. right eye
oculus sinister o.s. left eye
omni die o.d. daily
omni mane o.m. every morning
omni nocte o.n. every night
per os p.o. by mouth
placebo placebo to please
post cibos p.c. after meals
pro re nata p.r.n. as the occasion arises
quantum sufficiat q.s. sufficient quantity
quater in die q.i.d. four times a day
recipe Rx take
semis ss _ one-half
sine s,s without
si opus sit s.o.s. if necessary
ter in die t.i.d. three times a day
trochiscus, torchisci troch. lozenge, lozenges
unguentum ungt. ointment
ut dictum ut dict. as directed
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Estimating Lean Body Weight
Lean Body Weight Calculation: Males 50kg + 2.3kg per each inch over 5 feet of height
Females 45kg + 2.3kg per each inch over 5 feet of height
In patients whose actual weight is > 20% over the above calculated ideal body weight, add 40% of the difference between the actual and the calculated ideal weights to the calculated ideal weight to arrive at a corrected ideal body weight.
1kg = 2.2 lbs. 14 lbs. = 1 stone = 6.35 kg
Height Estimated Lean Body Weight
(+) or ( - ) 2.3kg per inch over/under 5 feet tall
(+) 50kg for men or (+) 45.5kg for women
Imperial / metric Males (kg) Females (kg)
4 ft 8 in / 142 cm 40.8 36.3
4 ft 9 in / 145 cm 43.1 38.6
4 ft 10 in / 147 cm 45.4 40.9
4 ft 11 in / 150 cm 47.7 43.2
5 ft 0 in / 152 cm 50.0 45.5
5 ft 1 in / 155 cm 52.3 47.8
5 ft 2 in / 157 cm 54.6 50.1
5 ft 3 in / 160 cm 56.9 52.4
5 ft 4 in / 163 cm 59.2 54.7
5 ft 5 in / 165 cm 61.5 57.0
5 ft 6 in / 168 cm 63.8 59.3
5 ft 7 in / 170 cm 66.1 61.6
5 ft 8 in / 173 cm 68.4 63.9
5 ft 9 in / 175 cm 70.7 66.2
5 ft 10 in / 178 cm 73.0 68.5
5 ft 11 in / 180 cm 75.3 70.8
6 ft 0 in / 183 cm 77.6 73.1
6 ft 1 in / 185 cm 79.9 75.4
6 ft 2 in / 188 cm 82.2 77.7
6 ft 3 in / 191 cm 84.5 80.0
6 ft 4 in / 193 cm 86.8 82.3
6 ft 5 in / 196 cm 89.1 84.6
6 ft 6 in / 198 cm 91.4 86.9
6 ft 7 in / 201 cm 93.7 89.2
6 ft 8 in / 203 cm 96.0 91.5