Equations Flashcards
Half-life
T1/2= (0.7*Vd)/(CL)
Maintenance dose
MD=(Steady state plasma concentration*CL)/(Bioavailibility fraction)
Loading dose
LD=(Volume of distribution * Steady state plasma concentration)/(Bioavailability fraction)
Cardiac output (using oxygen stuff)
CO=O2 consumption/arteriovenous difference
Volume of distribution (Vd)
Vd=amount of drug in the body/plasma drug concentration
Minute ventilation
Tidal volume x breath rate
Alveolar ventilation
(Tidal volume-dead space) x breath rate
Odds ratio
OR=(A/C)/(B/D)
or
OR=(AD)/(BC)
used in case-control studies
Odds ratio in words
Odds that the group w/ the disease (A/C) was exposed to the risk factor divided by the odds those w/out the disease (B/D) were exposed
Attributable risk
(a/(a+b))-(c/(c+d))
Number needed to treat
1/absolute risk reduction
Absolute risk reduction example
8% of people who receive a placebo develop disease and 2% of people who get vaccine develop the disease, the ARR is 6% (8-2=6, high level stuff)
Number needed to harm
1/attributable risk
Body mass index (BMI)
BMI=Weight(kg)/height(m)^2
Hardy-Weinberg equation
p^2 + 2pq +q^2=1=p+q
Drug clearance
CL=rate of elimination/plasma drug concentration
or Vd*Ke(elimination constant)
Mean arterial pressure
CO*TPR=2/3 diastolic + 1/3 systolic
Stroke volume
CO/HR=EDV-ESV
Ejection fraction
SV/EDV=(EDV-ESV)/EDV
Resistance
P/Q=(8n(viscosity))length/(pier^4)
Renal clearance
Cx=(Ux*V)/Px
GFR
GFR=Cinulin=Uinulin*V/Pinulin (creatinine can also be used to estimate)
Renal plasma flow
RPF=Cpah=Upah*v/Ppah
Renal blood flow
RBF=RPF/(1-Hct)
