Pharm midterm

Question 1

What is the Vd?

Answer 1

Amount of drug/ desired plasma concentration

Question 2

What does Vd assume?

Answer 2

Cannot undergo biotransformation till its fully absorbed

Drug distributes instantaneously

Question 3

What happens if a Vd exceeds TBW? (>42L) ?

Answer 3

Considered lipophilic

Needs higher dose to achieve given plasma concentration

Question 4

What happens if the Vd is less than TBW? <42L

Answer 4

Considered to be hydrophilic

Does not go into fat

Need less drug

Question 5

What is drug clearance proportinal to?

Answer 5

Blood flow to organ

Extraction ratio

Drug dose

Question 6

What is drug clearance inversely proportional to?

Answer 6

Half-life

Drug concentration

Question 7

What is steady state?

Answer 7

Rate of Administration = Rate of elimination

Question 8

What is the alpha distribution phase?

Answer 8

Drugs going from the plasma to the tissues?

Question 8

How many half lives to achieve steady state?

Answer 8

5

Question 9

What is the beta phase?

Answer 9

Drugs going from the tissues to reenter the plasma

Question 10

What is context sensitive half time?

Answer 10

** Does not consider time

Time required for the plasma to decline by 50%

Question 11

What happens to the context sensitive half time of fentanyl when it is given for an extended period?

Answer 11

Takes longer to eliminate because of the buildup in peripheral compartments

Question 12

*** What two factors determine the amount of ionization?

Answer 12

pH of the solution
pKa of the drug

Question 13

*** WHAT HAPPENS WHEN PKA AND PH ARE THE SAME??

Answer 13

50% OF THE DRUG IS IONIZED AND 50% IS UNIONIZED

Question 14

What drugs are more likely to undergo renal elimination ? Liver?

Answer 14

Renal - ionized
Liver - unionized

Question 15

What are weak bases usually paried with?

Answer 15

With a negative ion,

Chloride or sulfate

Question 16

What are weak acids usually paired with?

Answer 16

Positive ion such as Na, Ca, Mag

Question 17

What are 3 main plasma proteins?

Answer 17

Albumin
a1-acid glycoprotein
Beta globulin

Question 18

What conditions reduce serum albumin?

Answer 18

Liver and Renal disease
Old age
Malnutrition
Pregnancy

Question 19

What conditions decrease
a1-acid glycoprotein?

Answer 19

Neonates
Pregnancy

Question 20

If a drug is 98% bound and is reduced to 96% bound, what is the change?

Answer 20

100%

Question 21

***A drug is drug is cleared from the body at a rate proportional to plasma concentration, what model is this?

Answer 21

First order

Constant rate of fraction is eliminated per time

Question 22

What is zero order?

Answer 22

Drug is eliminated independent of plasma drug concentration

**Ex: 5mg every hour regardless of how much is in the body

Question 22

What drugs undergo zero order??

Question 23

What is a phase 2 reaction?

Answer 23

Adds a highly polar water substrate

CAN GO STRAIGHT TO PHASE 2

Glucuronic acid
Glycine
Acetic acid
Sulfuric acid
Methyl group

Question 24

What is enterohepatic circulation? Ex:?

Answer 24

Drugs secreted in bile are reabsorbed

Valium
Warfarin

Question 25

What is the extraction ratio?

Answer 25

How much of the drug is delivered and cleared by the organ

Question 26

ER of 1.0 means? ER of 0.5 means?

Answer 26

1.0 - Removes 100% of delivered drug

.5 - Removes 50% of delivered drug

Question 27

Which drugs are metabolized by pseudocholinesterase?

Answer 27

Succ, mivacurium
Tetracaine, Procaine, Benzocaine

Question 28

One drug that is biotransformed by alkaline phosphatase hydrolysis?

Answer 28

Fospropofol

Question 29

What is potency and how is it measured?

Answer 29

Dose required to achieve clinical effect

Question 30

Risk factors for propofol infusion syndrome?

Answer 30

4mg/kg.hr
Duration > 48 hours
Adults > children
Sepsis
Cerebral injury
Inadequate O2

Question 31

S+S of propfol infusion syndrome?

Answer 31

Brady
Asystole

Rhabdo
Metabolic acidosis
Renal failure
HLD
Fatty liver

Question 32

How do halogenated anesthetics produce immobility?

Answer 32

Ventral and Dorsal horn

Question 33

How do halogenated anesthetics produce unconsciousness?

Answer 33

Cerebral Cortex
Thalamus
RAS

Question 34

How do halogenated anesthetics produce amnesia?

Answer 34

Hippocampus
Amygdala

Question 35

How do halogenated anesthetics produce autonomic modulation?

Answer 35

Pons
Medulla

Question 36

What is CMRO2 a function of?

Answer 36

Electrical activity 60%
Cellular homeostasis 40%

Once isoelectric, cannot reduce any further

Question 37

How do gasses effect evoked potentials?

Answer 37

Visual - most sensitive
Brainstem - most resistant

SSEP and MEP are between

Question 38

Highest and lowest bioavailibility?

Answer 38

IV

Lowest - intrathecal

Question 39

What type of nerve is blocked first?

Answer 39

B
C
A

Question 40

What is a differential blockade?

Answer 40

Lower doses spare motor function, as dosage increases, motor is blocked

Question 41

What state are sodium channels unable to be bound to?

Answer 41

Resting

Question 42

What subunit do local’s bind to?

Answer 42

Alpha

Question 43

Three parts to local molecule?

Answer 43

Benzene ring- lipophilic

Intermediate chain- class, metabolism, allergy

Tertiary amine - hydrophilic

Question 44

How are the two classes of locals metabolized?

Answer 44

Esters- pseudocholinesterase
Amide- hepatic

*exception is cocaine - uses both for metabolism