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Flashcards in Pharmacokinetics Deck (52)
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1

Name the 6 main methods of drug administration

Oral
Intravenous (IV)
Intramuscular (IM)
Intraosseous (IO)
Subcutaneous
Topical

2

Where does most drug absorption take place?

Small intestine (duodenum - proximal)

3

How are drugs distributed throughout the body?

Bloodstream

4

Where does the majority of drug metabolism take place?

Liver

5

Where are drugs mainly excreted?

Kidneys

6

What two properties of drugs allow them to be well?absorbed by cells?

Fat soluble
Small in size

7

What two things happen during drug metabolism?

1. Drug broken down by removing fatty acid groups
2. Drug molecule 'built up' by adding water soluble groups

8

What property do drugs need to be excreted via the renal system?

Water solubility

9

List the 4 types of transmembrane proteins

Receptors
Pumps
Carriers
Channels/Pores

10

What is the most common way for drugs to pass through the cell membrane?

Simple diffusion

11

How can drugs use channels?

They can utilise or block them

12

Do pumps/carriers always require energy?

No

13

In drug distribution where does ~1/2 of the drug end up?

In tissues

14

Does a persons fat % affect drug distribution?

Yes it varies person to person

15

What plasma proteins do drugs bind to?

Albumin, Globulins and Fibrinogens

16

Does the brain recieve a higher % of CO than other tissues?

Yes

17

Why is the nervous system a significant reserve for drugs?

Due to the high proportion of fat cells (glial cells) contained in it

18

What are the 3 main features of brain capiliaries which help exclude some drugs from crossing the BBB?

1. One cell thick
2. Tight junctions
3. Surrounded by glial cells

19

What drugs do we want to pass over the BBB? (4)

Anaesthetics
Analgesics
Drugs targetting brain (antidepressants)

20

What is the purpose of the placental barrier?

To create a physical barrier between maternal and foetal blood

21

Where is maternal blood depositied? Where do foetal vessels interact with maternal blood?

Lacunae (intervillous spaces)

22

What property of foetal blood vessels helps exclude most toxins?

Selective permeability

23

What does metabolism aim to do?

Increases water solubility to promote excretion

24

How is metabolism achieved?

1. Addition of water soluble groups
2. Removal of fat soluble groups

25

What are the two main organs of metabolism?

Liver and Kidneys

26

Which drug types are converted to an active form by the liver due to their long half life?

Opiods and Benzodiazepines

27

Why would you want drugs to be metabolised from an inactive to an active form?

Drugs with specific target cells
To bypass the GI tract
(cancer drugs, viral therapies and anti inflammatories)

28

What is first pass metabolism?

A phenomenon whereby the concentration of a drug greatly reduces before reaching the systemic circulation

29

What 3 main methods of drug admin are subject to first pass metabolism?

1. Buccal/Oral
2. Rectal
3. GI absorption (via hepatic portal vein)

30

Why do children generally metabolise drugs faster?

They have a higher metabolic rate