Block 4: Revenge Of Clinical Pharmacokinetics

Front 1

Volume of Distribution

Back 1

Vd = total amount of drug in the body/drug blood concentration

Front 2

Ideal Body Weight (IBW) for a female with a medium body build

Back 2

100 lbs for 1st 5 ft, plus 5 lbs for each additional inch

Front 3

Ideal Body Weight (IBW) for a female with a small body build

Back 3

Calculate IBW, then subtract 10%

Front 4

Ideal Body Weight (IBW) for a female with a large body build

Back 4

Calculate IBW, then add 10%

Front 5

Ideal Body Weight (IBW) for a male with a medium body build

Back 5

100 lbs for 1st 5 ft, plus 6 lbs for each additional inch

Front 6

Ideal Body Weight (IBW) for a male with a small body build

Back 6

Calculate IBW, then subtract 10%

Front 7

Ideal Body Weight (IBW) for a male with a large body build

Back 7

Calculate IBW, then add 10%

Front 8

If the pt's total body weight (TBW) is less than their Ideal Body Weight (IBW), should you go with the TBW or the IBW?

Back 8

Go with the TBW

Front 9

What is the Cockroft-Gault equation?

Back 9

Creatinine Clearance = (140 - age) x Ideal Body Weight/72 x Serum Creatinine

Front 10

How do you modify the Cockroft-Gault equation for females?

Back 10

Multiply the CLcr you get by 0.85

Front 11

TRUE or FALSE: Some elderly pts w/serum creatinine values in the high-normal range will have almost normal renal fxn.

Back 11

TRUE

Front 12

TRUE or FALSE: the Cockroft-Gault equation will still work for pts with unstable renal fxn

Back 12

FALSE

Front 13

TRUE or FALSE: If the pt has a normal serum creatinine, they have normal renal fxn.

Back 13

FALSE

Front 14

You give a pt drug X. You take a blood level and decide to double the dose to get the pt into the therapeutic range. Two days later, the pt is lethargic. What happened?

Back 14

Possibly didn't wait long enough to take blood level, so pt wasn't in steady state when you decided to up the dose.

Front 15

Why do you need to be aware of 2 compartment kinetics?

Back 15

If you take a blood level too early, you may inappropriately decrease the dosage (digoxin's 2nd, slower elimination phase most closely mimics the concentration in the heart)

Front 16

Name four common causes of misleading drug concentrations.

Back 16

1)dose not given at correct time
2)drug concentration is ordered at correct time, but sample is collected early or late (but marked as collected at correct time)
3)failure to recognize a drug interaction affecting drug pharmacokinetics
4)non-compliance by pt

Front 17

t1/2=

Back 17

.693/k

Front 18

CL=

Back 18

Vd x k

Front 19

Dosing rate=

Back 19

CL x Css

Front 20

Maintenance dose=

Back 20

dosing rate x dosing interval

Front 21

loading dose=

Back 21

Vd x TC

Front 22

dose=

Back 22

change in C x Vd / F

F = bioavailability