required formulas

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1
BSA
2
BMI
3
tsp, tbsp
5ml, 15ml
4
1 oz
30 ml (29.47)
5
1 cup
8oz, 240 ml (236.56)
6
1 pint
16 oz, 480 ml (473)
7
1 quart
2 pints, 960ml (946)
8
1 gallon
4 quarts, 3840 ml (3875)
9
1 kg
2.2 lb
10
1 oz
28.4 grams
11
1 lb
454 grams
12
1 grain
65 mg (64.8)
13
mEq to mmol
1:1 for monovalent ions
1:0.5 for divalent ions
14
1 inch
2.54 cm
15
1 meter
100 cm
16
% w/v
x g/100 mL
17
% w/w
x g/ 100 g
18
% v/v
x mL/100 mL
19
ratio strength
100/ percentage strength
20
percentage strength
100/ ratio strength
21
PPM --> percentage strength
move the decimal left 4 places
22
percentage strength --> PPM
move the decimal right 4 places
23
specific gravity equation
grams of substance / grams of water
or
g/mL
dilution &concentration
(changing strength or volume)
24
2 concentrations given
Q1C1 = Q2C2
Q1 = old quantity
C1 = old conc
Q2 = new quant
C2 = neq conc
alligation
25
3 or more concentrations given
higher % strength X parts high %..........Y amt
desired
% strength
lower % strength X parts low %.......... Y amt
-----------------
total amount parts X% ...... Y amt

use proportions to calculate the amount if high or low percent required
will be given some of the x's and y's
26
mOsmol/L
(wt of substance (g/L)/MW (g/mol)) x(# particles) x1000
27
isotonicity (E value)
58.5i/1.8MW
28
MOLS
g/MW
29
MMOLS
mg/MW
30
mEq
(mg x valence)/MW
or
mmol x valence
31
corrected calcium (mg/dl)
for albumin <3.5
not needed when ionized calcium is given in labs
parenteral nutrition calories
dextrose monohydrate
32
(carbs)
3.4 kcalram
parenteral nutrition calories
amino acid solutions
33
(protein)
4 kcalram
parenteral nutrition calories
lipids (ILE)
34
(fats)
10% = 1.1 kcal/mL
20% = 2 kcal/mL
30% = 3 kcal/mL
enteral nutrition calories
dextrose or amino acids
35
(carbs or protein)
4 kcalram
enteral nutrition calories
lipids
36
(fats)
9 kcalram
37
determining fluid needs
when weight > 20kg
1500 mL + (20 mL)(wt in kg - 20)
**can estimate using 30-40 mL/kg/day
38
Total Energy Expenditure (TEE)
BEE x activity factor x stress factor
39
grams of nitrogen from protein
40
Crockcroft-Gault equation
41
BMI (kg/m2)
(wt kg)/(ht m)^2
or
[(wt lb)/(ht inch)^2] x 703
42
Ideal Body Weight (IBW)
43
Adjusted Body Weight
IBW + 0.4(TBW-IBW)
44
selecting patient weights for dosing calculations
all drugs, (if under weight) = use TBW
most drugs (if normal weight or obese) = use TBW
- under wt: TBW < IBW
- normal wt: TBW = IBW or TBW </= 1.2xIBW
- obese wt: TBW > 1.2xIBW
exceptions:
1) IBW for acyclovir, levothyroxine, aminophylline, theophylline (normal weight, obese)
2) AdjBW for aminoglycosides (obese)
45
flow rates drop factor (drops/min)
(drops/mL) x (mL/hr) x (1hr/60min) = drops/min
46
dehydration
BUN:Scr > 20:1
47
arterial blood gas (ABG)
ABG: pH/pCO2/pO2/HCO3/O2 sat
1) pH < 7.35 acidosis / pH > 7.45 alkalosis
2) respiratory: pCO2 < 35 alkalosis / pCO2 > 45 acidosis
metabolic: HCO3 > 26 alkalosis / HCO3 < 22 acidosis
3)which abnormal value matches the pH from step #1?
ROME: Respiratory Opposite Metebolic Equal
Ex 1: decreased pH + increased pCO2 = resp acidosis
Ex 2: increased pH + decreased pCo2 = resp alkalosis
Ex 3: decreased pH + decreased HCO3 = meta acidosis
Ex 4: increased pH + increased HCO3 = meta alkalosis
48
Anion Gap
Na - Cl - HCO3
pH calculation
49
weak acid

pH calculation
50
weak base

percent ionization
51
weak acid
100 / 1+10^(pKa-pH)
percent ionization
52
weak base
100 / 1+10^(pH-pKa)
53
Absolute Neutrophil Count (ANC) cells/mm^3
where segs = neutrophils
temperature conversion
54
celsius
(F-32)/1.8
temperature conversions
55
fahrenheit
(Cx1.8)+32
56
mean, median, mode
mean = average value
median = value in the middle of an ordered list
mode = value that occurs most frequently
57
Risk
# with unfavorable event in group / total in group
58
Relative Risk (RR)
risk in TMT group / risk in CTRL group

when RR = 1 (or 100%) then no diff b/t grps
when RR < 1 (or 100%) then benefit w/ drug
when RR > 1 (or 100%) then no benefit (harm?) w/ drug
59
Relative Risk Reduction (RRR)
(% risk CTRL grp - % risk TMT grp) / (% risk CTRL grp)
60
Absolute Risk Reduction (ARR)
(% risk CTRL grp) - (% risk TMT grp)
61
NNT or NNH
100/ARR**
**AS A PERCENT
62
odds ratio (OR)
outcome
yes no

yes (TMT) A B
exposure
no (CTRL) C D
----------------------------------------------------------
OR = AD/BC

(# w/outcome TMT) x (# w/out outcome CTRL)
OR = ---------------------------------------------------
(# w/out outcome TMT) x (# w/outcome CTRL)
63
Odds Ration (OR)
hazard rate in TMT grp / hazard rate in CTRL grp
64
sensitivity
measures how well a test can correctly identify patients WITH the condition (TRUE POSITIVE)

= [TP / (TP + FN)] X 100
65
specificity
measures how well a test can correctly identify patients WITHOUT the condition (TRUE NEGATIVE)

= [TN / (TN + FN)] X 100
66
time to burn (TTB)
TTB (without sunscreen) x SPF
67
initiating basal-bolus insulin in T1DM
1) calculate TDD 0.6 units/kg/day using TBW
2) divide into 1/2 basal & 1/2 rapid acting
- If using NPH/R use 2/3 & 1/3
3) split rapid acting among meals
insulin to carb ratio
68
rule of 500 for rapid acting insulin
500/TDD = g carbs covered by 1 unit RA insulin
insulin to carb ratio
69
rule of 450 for regular insulin
450/TDD = g carbs covered by 1 unit regular insulin
correction factor
70
rule of 1800 for rapid acting insulin
1800/TDD = correction factor for 1 unit RA insulin
correction factor
71
rule of 1500 for regular insulin
1500/TDD = correction factor for 1 unit regular insulin
72
correction insulin dose equation
(BG now - target BG) / correction factor
73
LDL (friedewald equation)
TC - HDL - (TG/5)
**do not use if TG > 400
74
minimal weighable quantity (MWQ)
sensitivity requirement / 0.05
75
BSA calculation
m^3 = square root of [(cm x wt)/3600]
**use for oncology chemo calculations
76
Bioavailability (F, %)
100 x (EV AUC / IV AUC) x (IV dose / EV dose)

EV = extravascular
77
volume of distribution (Vd)
AMT drug in body / conc drug in plasma
78
clearance
(F x dose)/AUC
or
Ke x Vd
79
elimination rate constant (Ke)
Ke = Cl/Vd
80
predicting drug concentrations
C1 = C2 x e^-kt
Ke = ln(C1/C2) / t
81
half-life (t1/2)
0.693/Ke
82
loading dose (LD)
(desired conc x Vd) / F
83
Phenytoin correction (mcg/mL)
= total phenytoin measured / [(0.2 x albumin) + 0.1]
** for albumin < 3.5, not needed for free phenytoin, can also be used for valproic acid
84
KCl solution (oral) to tablets
KCl 10% = 20 mEq/15 mL
KCl 20% = 40 mEq/15 mL
85
Calcium salts
calcium carbonate = 40% elemental calcium
calcium citrate = 21% elemental calcium
86
aminophylline <--> theophylline
A-->T : multiply by 0.8 (remember: ATM)
T-->A : divide by 0.8 (remember: TAD)
87
Loop diuretics
ethacrynic acid = 50 mg
furosemide = 40 mg
torsemide = 20 mg
bumetinide = 1 mg

furosemide IV:PO = 1:2
other loops IV:PO = 1:1
88
metoprolol conversions
IV:PO = 1:2.5
89
iron elemental conversions
ferrous sulfate = 20% elemental iron
e.g. 325 mg x 0.2 = 65 mg
90
insulin conversions
usually, 1:1 conversion

EXCEPTIONS:
1) NPH dosed BID to glargine dosed daily --> use 80% NPH dose
2) Toujeo --> Lantus or Basaglar, use 80% Toujeo dose
91
Steroid conversions
Cute Hot Pharmacists & Physicians Marry Together & Deliver Babies

Cortisone 25 mg
Hydrocortisone 20
Prednisone 5
Prednisolone 5
Methylprednisolone 4
Triamcinolone 4
Dexamethasone 0.75
Betamethasone 0.6
92
Statin conversions
Pharmacists Rock At Saving Lives & Preventing Fatty-deposits

Pitavastatin 2 mg
Rosuvastatin 5
Atorvastatin 10
Simvastatin 20
Lovastatin 40
Pravastatin 40
Fluvastatin 80
93
Opioid conversions
morphine 10 mg IV/IM --> 30 mg PO
hydromorphone 1.5 mg IV/IM --> 7.5 mg PO
94
CYP3A4 inducers
PS CROPS
decrease substrate concentrations --> decrease effect
subtherapeutic doses --> treatment failure

Phenytoin
Smoking
Carbamazepine
Rifampin
Oxcarbazepine
Phenobarbital
St. John's Wort
95
CYP3A4 inhibitors
G PACMAN
increase substrate concentrations --> increase effect
supratherapeutic doses --> more toxicity

Grapfruit
Protease inhibitors (-navir)
Cobicistat, Cyclosporine
Macrolides
Amiodarone
Non-DHP CCB (verapamil, diltiazem)
96
warfarin colors
Please Let Granny Brown Bring Peaches To Your Wedding

Pink 1 mg
Lavender 2 mg
Green 2.5
Brown 3
Blue 4
Peach 5
Teal 6
Yellow 7.5
White 10
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