Formulas

Question 1

Covert C to F

Answer 1

F= (C * 1.8) +32

Question 2

Convert F to C

Answer 2

C = (F-32)/1.8

Question 3

% w/v

Answer 3

X g/ 100 mL

Question 4

% v/v

Answer 4

X mL/ 100 mL

Question 5

%w/w

Answer 5

X g/ 100 g

Question 6

Precent Strength =

Answer 6

100/ ratio strength

Question 7

Ratio Strength =

Answer 7

100/ percent strength

Question 8

PPM –> Percentage Strength

Answer 8

move the decimal LEFT 4 places

Question 9

Percentage Strength –> PPM

Answer 9

move the decimal RIGHT 4 places

Question 10

Specific Gravity =

Answer 10

G / mL

Question 11

mOsmol/L =

Answer 11

wt of substance (g/L) / MW (g/mole) * # of particles * 1,000

Question 12

Isotonicity (E) =

Answer 12

(58.8) (i) / (MW of drug)(1.8)

Question 13

moles =

Answer 13

Gram/ MW

Question 14

mmoles =

Answer 14

mg / MW

Question 15

mEq =

Answer 15

mg * valence / MW

OR

mmols * valence

Question 16

Enteral Nutrition
Carbs:
Protein:
Fat:

Answer 16

Carbs: 4 kcal/g
Protein: 4 kcal/g
Fat: 9 kcal/gram

Question 17

Parenteral Nutrition
Dextrose:
Amino Acid:
ILE 10%:
ILE 20%:
ILE 30%:

Answer 17

Dextrose: 3.4 kcal/g
Amino Acid: 4 kcal/g
ILE 10%: 1.1 kcal/ml
ILE 20%: 2 kcal/ml
ILE 30%: 3 kcal/ml

Question 18

Determine Fluid needs

Answer 18

when weight > 20 kg:
1500 mL + (20mL)(wt in kg - 20)

Question 19

Total Energy Expenditure

Answer 19

TEE = BEE * activity factor * stress factor

Question 20

grams of nitrogen from protein

Answer 20

N = protein intake (g) / 6.25

Question 21

Corrected calcium (from when albumin < 3.5)

Answer 21

Ca reported + [(4-albumin) * .8]

Question 22

BMI

Answer 22

[weight (lbs) / (ht in inches)^2 ] * 703

Question 23

IBW males:
IBW females:

Answer 23

IBW males: 50 + (2.3 * inches. over 5 ft)
IBW females: 45.5 + (2.3 * inches over 5 ft)

Question 24

Adjusted Body weight

Answer 24

IBW + .4 (TBW-IBW)

–> use for aminoglycosides (obese)

Question 25

What drugs do you use IBW always

Answer 25

-acyclovir
-aminophylline
-levothyroxine
-theophylline

Question 26

Flow rate/Drop factor (drops/min)

Answer 26

drop / mL * mL/hr * hr/60 min

Question 27

How to determine dehydration based on lab values

Answer 27

BUN:Scr = 20:1

Question 28

Anion gap

Answer 28

Na- Cl - HCO3

Question 29

pH calculation for weak acid

Answer 29

pH = Pka + log (salt/acid)

Question 30

pH calculation for weak base

Answer 30

pH = Pka + log (base/salt)

Question 31

% ionization for weak acid

Answer 31

100 / ( 1+ 10 ^(Pka- pH)

Question 32

Time to burn

Answer 32

TTB = SPF * TTB (w/o sunscreen)

Question 33

% ionization for weak base

Answer 33

100 / ( 1+ 10 ^ (pH - PKa)

Question 34

Absolute Neutrophil Count

Answer 34

ANC = WBX * [ (segs + bands) / 100]

Question 35

Pack year smoking history

Answer 35

cig packs/day * years smoked

Question 36

Friedewald Equation

Answer 36

LDL = TC - HDL - (TG/5)

*do not use if TG > 400

Question 37

Minimal weighable quantity (MWQ)

Answer 37

(sensitivity requirement) / (acceptable error rate - usually 0.05)

Question 38

BSA calculation

Answer 38

sq rt [ (ht in cm * wt in kg) / 3600]

Question 39

Bioavailability (F)

Answer 39

100 * (AUC extravas / AUC intravas) * (dose inta/ dose extra)

Question 40

Volume of distribution

Answer 40

(amount of drug in the body) / (concentration of drug in the plasma)

Question 41

Clearance (cl)

Answer 41

F * dose / AUC
OR
ke * Vd

Question 42

Elimination rate constant (ke)

Answer 42

Cl/ Vd

Question 43

Predicting Drug Concentrations

Answer 43

C2 = C1 * e ^(-kt)

ke = (ln (c1/c2)) / t

Question 44

Half life (t 1/2)

Answer 44

0.693 / ke

Question 45

Loading Dose

Answer 45

(desired concentration * vd) / F

Question 46

Mean arterial Pressure (MAP)

Answer 46

[ (2 * diastolic pressure) + systolic pressure] / 3

Question 47

Phenytoin (total) correction for albumin < 3.5

Answer 47

(total. phenytoin measured) / (0.2 * albumin) + 0.1