Formulas Flashcards
tsp (t)
5 mL
tbsp (T)
15 mL
1 f oz
30 mL (actual 29.57 mL)
1 cup
8 oz, 240 mL (approx.); 236.56 mL (actual)
1 pint
16 oz, 480 mL (approx.); 473 mL (actual)
1 quart
2 pints, 960 mL (approx.); 946 mL (actual)
1 gallon
4 quarts, 3,840 mL (approx.); 3,785 mL (actual)
1 kg
2.2 pounds (lbs)
.
So to find Lbs from Kg? x 2.2
1 oz (to grams)
28.4 grams (g)
1 lb to grams
1 lb = 454 g
1 grain to mg
1 grain = 65 mg (approx.); 64.8 mg (actual)
Inch (in) to cm
2.54 centimeters (cm)
cm to mm
x 10
cm –> mm? cm * 10 = mm
Meter (m) to cm
Meter (m) = 100 cm
Ratio Strength
Percentage strength(%)= 100 / Ratio strength
.
Ratio strength(#:#) = 100 / Percentage strength
Parts Per Million (PPM) and percentage strength
PPM –> Percentage strength Move the decimal left 4 places to get % strength
.
Percentage strength–> PPM Move the decimal right 4 places (to get PPM)
Calculations of ppm
Express 5 ppm of iron in water in percentage strength and ratio strength
PPM to percentage? think of 1 PPM as 1/1,000,000… which is 0.000001 or *100 = 0.0001%
.
So 5 PPM = 5/1,000,000 = 0.000005% or *100 = 0.0005%
.
LONG STORY SHORT = divide ppm/10,000
% strength to PPM?
Just multiple % * 10,000!
Changing Strength or Volume (Dilution & Concentration)
Q1 x C1 = Q2 x C2
.
Q1 = old quantity Q2 = new quantity
C1 = old concentration C2 = new concentration
Osmolarity
Isotonicity (E-value)
E = (58.5)(i)/ (MW of drug)(1.8)
mEq
mg * valance / mw
BMI (kg/m2)
kg/m^2
or
lbs/inches^2 * 703
Ideal Body Weight (IBW) male? female?
IBW (males) = 50 kg + (2.3 kg)(number of inches over 5 feet)
.
IBW (females) = 45.5 kg + (2.3 kg)(number of inches over 5 feet)
AdjBW
IBW + 0.4(TBW – IBW)
CrCl (mL/min)
Mean, Median and Mode
Mean - the average value
.
Median - the value in the middle of an ordered list
.
Mode - the value that occurs most frequently
Relative Risk (RR)
suck in treatment/ suck in control
Relative Risk Reduction (RRR)
%SC-%ST/ %SC * 100
Absolute Risk Reduction (ARR)
ARR = (% risk in control group) – (% risk in treatment group) .. . think of top RRR *100
NNT (ROUND UP)
1/ %SC-%ST
Odds Ratio (OR)
Sensitivity and Specificity
Pack year smoking hx
cig packs/day * years smoked
Incremental cost ratio
C2-C1/ E2-E1
c= cost
e= effects
Minimum weighable quantity MWQ
MWQ = sensitivity requirement/ acceptable error rate (usually 0.05)
Bioavailability (F)
F% = 100* AUC extra/AUC intra * Dose intra/Dose extra
Volume of distribution
Vd = amount of drug in body (in mg) / conc of drug in plasma (peak level in mg/L)
Clearance (CI)
CI = Fdose/ AUC
or
CI = keVd
Half life t1/2
t1/2 = 0.693/ke
Loading Dose
(desired conc * Vd) / F
Common Valance to know?
of particles dissociation?
IV dose to oral dose formula?
IV dose = oral dose * (bioavailability/ 100)
mg to dL
.
ml to dL
1 mg = 0.01dL
.
mL —> dL (ml * 100) 100mL is 1 dL
mcg to mg
1 micrograms (mcg) is equal to 0.001 milligrams (mg). Conversely, 1 milligrams (mg) is equal to 1000 micrograms (mcg).
Relative Risk
Relative Risk Reduction
Absolute Risk Reduction
no neg
NNT/NNH
NNT = round up
NNH = round down
1 ppm to mg?
1 ppm = 1 mg per liter
Million
1,000,000 (6 zeros)
Young’s rule
Density
Density = mass/volume (g/mL)
.
SIMILAR TO SG!!!!
Specific Volume
Volume of substance (mL sub) / Volume of equal weight of water (mL h20)
From the following formula for 40 sertraline capsules, calculate the factor that would be used if a pharmacist wished to prepare 250 capsules
Factor = want/give
.
F = 250/40 = 6.25
so wanna know gram needed? x 6.25!