Week 2- II Pharmacokinetics Flashcards

1
Q

What is the blood-brain barrier? Name two ways drugfs enter the brain.

A

The capillaries of the brain do not have gaps between the cells of the capillaries. Drugs must pass through the cell membrane or be transported by a transport system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The cytochrome P450 system refers to a family of enzymes which does what?

A

Metabolize drugs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Kidneys are unable to excrete what type of drugs?

A

Highly lipid-soluble.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define prodrug.

A

An inactive compound which can be converted into an active drug.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define the first-pass effect.

A

Blood passes through the liver before reaching the systemic circulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does cigarette smoking affect the rate of drug metabolism?

A

Increases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

If a drug binds to albumin and displaces another drug from the site, what happens to the serum concentration of the drug displaced?

A

Increases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

At what age does the infant’s liver develop into its full capacity?

A

One year.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The most important organ for drug excretion is what?

A

The kidneys.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which drugs remain in the urine for excretion?

A

Polar and ionized drugs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define enterohepatic circulation.

A

Drugs excreted in the bile are reabsorbed into the portal blood.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What type of drugs easily enters breast milk?

A

Lipid-soluble or lipophilic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define the minimum effective concentration (MEC).

A

The plasma drug level at which a drug has a therapeutic effect.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define toxic concentration.

A

The plasma drug level at which toxic effects begin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define therapeutic range.

A

The range of plasma drug levels that fall between the MEC and the toxic concentration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define duration.

A

The length of time the drug is in the therapeutic range.

17
Q

Define half-life.

A

The time required for the amount of drug in the body to decrease by 50%. For example if the half-life is one day, in 1 day, 50% is left; in 2 days, 25% is left; in 3 days, 12.5% is left; etc.

18
Q

How many half-lives does it take to clear a drug from the body?

A

4 half-lives

19
Q

Define plateau. What is the relationship between absorption and elimination?

A

Steady concentration of drug reached after repeated doses.

Absorption = Elimination

20
Q

Why are loading doses given?

A

To shorten the time to plateau.

21
Q

Why are maintenance doses given?

A

To continue the plateau.

22
Q

What type of drugs cross the placenta?

A

Lipid-soluble or lipophilic.