NAPLEX required formulas
RRR
(%risk in control group-%risk in trt group) / % risk in control group
correction dose
(blood glucose now) - (target blood glucose) / CF = correction dose
compounds and their valencies
*valency of 1* Ammonium Chloride (NH4Cl) Potassium Chloride Kcl potassium gluconate KC6H11O7 sodium acetate NaC2H3O2 sodium bicarb NaHCO3 sodium chloride *valency of 2* calcium carbonate CaCO3 calcium chloride CaCl2 ferrous sulfate FeS02-4 magnesium sulfate MgSO2-4 *(divalent ions 1 mEq=0.5mmol)*
rule of 500
for use with rapid acting insulin 500/TDD = grams of carbs covered by 1 unit of rapid acting insulin
rule of 450
for use with regular insuin 450/TDD = grams of carbs covered by 1 unit of regular insulin
mols or mmols
g/MW or mg/mw
SG
g/mL
HR
hazard rate in trt group / hazard rate in control group
mEq
mg x valence / MW or mEq = mmol x valence
ARR
(% risk in control group) - (%risk in treatment group)
t1/2
0.693/ke
NNT or NNH
1/ARR
ratio strength
100/percentage strength
percentage strength
100/ratio strength
correction factor
1800 rule - rapid acting insulin 1800/TDD = CF for 1 unit of rapid acting insulin 1500 rule - regular insulin 1500/TDD = CF for 1 unit of regular insulin
1 oz
28.4g
IBW for females
45.5kg + (2.3kg)(# of inches over 5 feet)
IBW for men
50kg + (2.3kg)(# inches over 5 feet)
1 grain
65mg
OR
AD/BC
dehydration
BUN:Scr > 20:1
Farenheit -- celsius
C = (F-32)/1.8 F = (Cx1.8) + 32
Corrected Calcium (when alb <3.5, unless ionized Ca given)
Calcium reported + [(4.0-albumin) x 0.8]
isotonicity
E = (58.5)(i) / (MW of drug)(1.8) i = ionization factor/dissociation factor number of dissociated ions being 1 a dissociation factor of 1 then everything after that you add 0.8 so a number of dissocated ions being 2 = dissoc factor of 1.8
Bioavailability
F (%) = 100 x AUCev/AUCiv X DOSEiv/DOSEev
ABW
IBW + 0.4(TBW-IBW)
Elimination Rate constant
Ke = cl/vd
Anion Gap
Na-Cl-HCo3
Cl
Rate of elim (ke) / Conc or F X dose / AUC
BSA calculations
SQUARE ROOT!!! OF (ht (cm) x wt (kg) ) / 3600 sidenote: carboplatin is dosed by the calvert formula -- total carbo dose (mg) = target AUC x (GFR+25)
ANC
WBC x [(segs + bands )/100]
BMI
Weight (kg) / height (m2) <18.5 underweight 18.5-24.9 normal 25-29.9 overweight 30+obese
calcium % elemental
carbonate 40% elemental citrate 21% elemental
LD
desired concentration x Vd / F
Calculating a dose of new dosage form
dose of new dosage form = amount absorbed from current dosage form/F of new dosage form
Vd
dose/cp (amount of drug in body/conc. of drug in plasma)
Dubois-Dubois formula
for BSA for oncology BSA (m2) = 0.007184 x [cm]^0.725 / [kg]^0.425
PPM --> percentage strength
move the decimal 4 places left
percentage strength --> PPM
move the decimal place 4 places right
Risk
number of subjects with unfavorable event in group/total number of subjects in the group
percent ionization weak base
pH = pKa + log [base/salt]
percent ionization weak acid
pH = pKa + log [salt/acid]
ABG
pH/pCO2/PO2/HCO3/O2sat pH <7.35 --> acidosis pH >7.45 --> alkalosis CO2: 35-45 HCO3 22-26
RR
risk in trt group / risk in control group
Sensitivity and specificity
see sheet
MWQ (minimum weighable quantity)
sens. requirement / 0.05
phenytoin correction
total pheny measured / (0.2xalbumin) + 0.1
calculating osmolarity mOsm/L
wt of substance (g/L) / MW x # particles x 1,000 # of particles: Kcl, NaCl, Na acetate = 2 CaCl2 = 3 Na Citrate (Na3C6H5O7) = 4