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Flashcards in Topic 2 Deck (19):
1

What is an example of a drug that ends up in fat stores

anaesthetic thiopentone (sodium pentothal)

2

What is anaesthetic thiopentone classified as

ultra-short acting anaesthetic

3

Why does anaesthetic thiopentone act rapidly

as it is highly lipid soluble so it readily crosses the blood brain barrier where it quickly exerts its anaesthetic effect.

4

What does the lipid solubility of anaesthetic thiopentone mean in terms of the time of its effect

it also leaves the brain very rapidly with its effects lasting only about 5 minutes, and then it is taken up by fatty tissue in the body and slowly released into the liver where it is metabolised.

5

How do surgical procedures work around anaesthetic thiopentone lasting shortly

they quickly induce anaesthesia with intravenous thiopentone that acts almost instantaneously, while the more slowly acting agents given by inhalation begin to take over and maintain the anaesthesia for the duration of the surgery

6

What are other tissues where drugs may be stored

muscle, liver, lungs, fat or bone.

7

Example of drug being stored in bone

tetracycline antibiotic that has an affinity for calcium and magnesium, may be taken up by teeth and bone, where large amounts of calcium are found (thus not given to young children as it can cause discolouration of the teeth).

8

What are the tissues and tissue components that serve as reservoirs for drugs

plasma proteins; fat stores; muscle; liver; lung; bone

9

What happens when the drug is bound up in these stores

they are usually unavailable for action.

10

What happens while the drug is being distributed throughout the body

metabolism

11

Metabolism

breaking down the drug

12

Can some drugs be metabolised prior to absorption

yes, e.g. alcohol

13

Where is the main site of metabolism

the liver

14

Where are other sites of metabolism

digestive tract; lungs; blood

15

What does the liver act like

the body’s chemical processing plant. It is the site of continuous and carefully controlled activity.

16

Everything that enters the bloodstream (swallowed/injected/inhaled/absorbed through skin/produced by body itself) is carried to where

to the liver

17

Substances in the liver are chemically transformed by

enzymes

18

The liver decreases the what of some drugs

bioavailability

19

Is metabolism constant

no