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Flashcards in Pharmacokinetics Deck (38)
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1
Q

What does enteral administration mean?

A

Using the GI tract (oral, sublingual, buccal, rectal)

2
Q

What does parenteral mean?

A

Non-GI delivery

IV, IM, SQ, intrathecal, epidural

3
Q

What route of administration get the greatest level of compliance?

A

Enteral

4
Q

What is the problem with using the GI tract for administering drugs?

A

Digests the drugs

5
Q

What is buccal administration? What is the advantage of using this route, as compared to other enteral routes?

A

Placing drug between tongue and cheek

Bypasses the liver

6
Q

What are the two major disadvantage of parenteral administration of a drug?

A

Pierce the skin, lowers compliance

No way to reclaim drug

7
Q

Which route of administration gives the highest bioavailability?

A

Parenteral (IV)

8
Q

What is the general type of chemical that is absorbed across the buccal mucosa?

A

Lipid soluble

9
Q

What percent of a drug that is given rectally bypasses the liver?

A

~50%

10
Q

What can significantly impact the absorption of a drug administered IM?

A

Exercise/fat distribution

11
Q

What is the specific advantage of SQ administration of a drug?

A

Constant rate of absorption over a long period of time

12
Q

What is intrathecal administration of a drug?

A

Injection into the subarachnoid space

13
Q

What is transdermal administration?

A

Think patches

14
Q

Lipophilic, or hydrophilic drugs are more likely to be successful with paradermal route of administration

A

Lipophilic

15
Q

What type of drug side effects should cause concern for giving them via inhalation?

A

Anything that upsets the heart

16
Q

What is the charged form of a weak base: protonated or unprotonated?

A

protonated

17
Q

What is the charged form of a weak acid: protonated or unprotonated?

A

Unprotonated

18
Q

Which can pass through a lipid bilayer more easily: charged or uncharged substances?

A

Uncharged

19
Q

How can the henderson-hasselbach equation be used in pharmacokinetics?

A

check protonated form in relation to the pH of a given solution

20
Q

What is the pKa?

A

pH at which [protonated form] = [unprotonated form]

21
Q

Weak acids are more likely to be absorbed where?

A

stomach d/t low pH

22
Q

Weak bases are more likely to be absorbed where?

A

Intestines

23
Q

What are the four major factors of drug distribution?

A
  1. Cardiovascular factors
  2. Tissue binding
  3. Drug molecule size
  4. Lipid solubility
24
Q

What is the technical definition of drug distribution?

A

The process by which a drug leaves the circulation and enters the tissues perfused by the blood

25
Q

What is the role of proteins in the blood and drug distribution?

A

Drugs can bind to proteins, leaving less available to distribute

26
Q

What is phase I of biotransformation?

A

Generate a more polar molecule by exposing a functional group on the parent compound.

27
Q

What is phase II of biotransformation?

A

Reactions yielding a more water soluble conjugated product to be excreted

28
Q

What is the rate limiting step in biotransformation?

A

p450 enzymes in the ER

29
Q

Where are the products of phase II of biotransformation excreted?

A

Bile canaliculi

30
Q

Do all drugs go through phase I and II biotransformation?

A

no

31
Q

What are the three most common reactions done in phase II?

A

Glucuronidation
Sulfation
Acetylation

32
Q

What is the role of UDP?

A

Conjugates metabolites to be excreted

33
Q

What is the “first pass” effect?

A

Drug absorbed by the stomach or intestines will initially be carried to the liver by the portal vein

34
Q

What are the three major factors that determine the renal excretion?

A

GFR
Plasma protein binding
pH of urine

35
Q

How are most drug metabolites excreted into feces? (2)

A

Bile

Hepatocytes secrete directly into GI tract

36
Q

What is the volume distribution?

A

The measure of space in the body available to contain a drug

37
Q

What is clearance?

A

Measure of the ability of the body to eliminate a drug

38
Q

What are the two major factors that determine the amount of drug within the body?

A

Distribution and elimination