Pharm exam I misc q's

Question 0

Phase I metabolism involves primarily what chemical reactions?

Answer 0

Oxidation, reduction, and hydrolysis

Question 1

The driving forces for diffusional distribution into a tissue are what?

Answer 1

relative solubility, conc gradient, rate of blood flow

Question 2

Enzyme CP-450 requires what to become active?

Answer 2

an electron donor (from NAD-coenzymes formed from naicin)and molecular O2

Question 3

Under low conditions of Partial Pressure O2, enzyme CP-450 does what?

Answer 3

transfers electron to a substrate rather than to oxygen (insufficient amount of O2 to compete for electrons) This can lead to certain toxic build up.

Question 4

Drugs that rely on the Oxidation pathway can lead to what?

Answer 4

Toxicity

Question 5

What is conjugation?

Answer 5

another metabolism method that uses CP-450 to render substance inactive and water soluble therefore available for elimination.

Question 6

If decreased enzyme activity interferes with conjugation what can happen?

Answer 6

the drug is prone to toxicity (risk of hyperbilirubinemia in neonates)

Question 7

Does Hydrolysis use microsomal enzymes CP-450 for metabolism?

Answer 7

No

Question 8

What is the Phase II metabolic pathway?

Answer 8

Conjugation

Question 9

Where does hydrolysis often work to metabolize drugs?

Answer 9

often at ester bonds

Question 10

Does enzyme induction affect non-microsomal metabolism?

Answer 10

No its activity is genetically determined.

Question 11

How is volume of distribution proportional to protein binding?

Answer 11

inversely

Question 12

What is pKa?

Answer 12

the pH at which a drug is 50% ionized and 50% unionized

Question 13

A drug is a weak acid if it forms a salt with what?

Answer 13

a positive ion ie. Na+, K+, Ca+, Mg+

Question 14

A drug is a weak base if it forms a salt with what?

Answer 14

A negative ion ie. Cl-, SO4-,

Question 15

Small changes in pH does what in ionization?

Answer 15

cause large changes in ionization (example if you take an acid that is 50% ionized and add 2 pH points more basic it becomes 90% ionized)

Question 16

Are local anesthetics weak acids or weak bases?

Answer 16

Weak bases

Question 17

If a drugs pKa is close to bloods pH will it work faster or slower?

Answer 17

faster ex drug with pka= 7.9 and blood pH= 7.45 will work faster than drug with pKa=8.16 in blood with pH=7.45

Question 18

What is important to note about circumventricular organs?:

Answer 18

areas where the BBB is weak (ex area postrema= vomit center)

Question 19

Are NMBD lipid soluble?

Answer 19

No they are poorly lipid soluble and remain in blood longer but take their action after leaving central compartment.

Question 20

What determines rate of metabolism?

Answer 20

1. concentration of drug at site of metabolism (hepatic blood flow)
2. Intrinsic rate of the metabolic process

Question 21

First order kinetics are what?

Answer 21

metabolic enzymes not saturated and amount of drug metabolized is proportional to drug concentration

Question 22

What is zero order kinetics?

Answer 22

metabolic enzymes are saturated and can only metabolize constant amount of drugs per unit of time.

Question 23

What is MAC?

Answer 23

(Minimum aveolar concentration) the inspired concentration at 1 atm that prevents skeletal muscle movement in response to painful stimuli in 50% of patients

Question 24

When inspired gas concentration = expired gas concentration what is this called?

Answer 24

equilibrium and anesthesia can be anticipated (O&J pg. 164)

Question 25

Uptake of an inhaled gas is the product of what 3 things?

Answer 25

Uptake= Cardiac Output x concentration gradient (alveolar to venous partial pressure difference) x blood-to-gas solubility.
* If any of these = 0 as in cardiac arrest, no concentration gradient, or agent is insoluble in blood than uptake is impossible