Pharmocokinetics

Question 1

What are the fates of drug distribuition in the body

Answer 1

• Binding and storage in tissues
• Biotransformation (into metabolites)
• Metaboluites in systematic circulation
• Renal excretion
• Biliary excretion

Question 2

How does protein bind to drugs (method)

Answer 2

Non-covelent binding (also reverible to maintain bound:free)

Question 3

How can drug interactions be explained due to protein binding and ex

Answer 3

2 drugs may both bind to albmin but one may displace the other off of it increasing the free concentration of the drug causing a increased phamo effect (as + morophine)

-Low albumin can also cause this

Question 4

What is the isoelectric point and what does it indicate

Answer 4

Ph5= 100 pos and 100 neg charges

Question 5

What can increased billirubin but low albumin cause

Answer 5

increased conc of free biliirubin causing jaudice

Question 6

What causes kernicterus

Answer 6

failled billirubin tx where it will actially migrate to brain tissue staining it

Question 7

How will non polar vs charged molecules move thru body water

Answer 7

charged molecules will only be in extracellular space where non polar will distribute thru total body water

Question 8

What is the calculation for conc of a drug + apparent volume of distribution

Answer 8

Concentration (drug in plasma)= mass (ammount of drug)/ Volume (of distribution)

Vd= mass of drug given/ conc in plasma

Question 9

For meaningful interpretation of the apparent volume of distribution you should

Answer 9

Should be evaluated from the conc of the free unbound drug

Question 10

What is half life

Answer 10

is the time elapsed for its plasma conc to be reduced by 50%

Question 11

How much longer is the effect of the drug extended when dose it doubled

Answer 11

extended by one half life

Question 12

how many hal lifes does it take to reach steady state in oral administration

Answer 12

5

Question 13

What is the wash out period and how long does it take to get back to a drug conc of zero after stopping IV

Answer 13

wash out period- when administration is stopped

-5 half lives to reach zero

Question 14

When you repetedly administer an oral drug to steady state what will you see

Answer 14

Will see a rise and fall in conc slow and steady up until steady state

Question 15

How many half lives will it take to reach steady state again if you double dose

Answer 15

5

Question 16

how to asses oral bioavaility compared to IV (equation)

Answer 16

bioavailality= (AUC oral/AUC IV) * 100

auc=area under curve

Question 17

What is the formula for desired dose

Answer 17

volume of distribution* desired dose/ bioavailability

Bioavail= 1 in IV