Prescribing in Clinical Dentistry

Question 1

What does enteral administration?

Answer 1

oral

Question 2

What are the advantages of oral administration of a drug?

Answer 2

socially acceptable

Question 3

What are the 4 disadvantages of oral administration?

Answer 3

slow onset
variable absorption
gastric acid may destroy drug
‘first pass’ metabolism

Question 4

Where does blood from the GI tract enter?

Answer 4

liver

Question 5

How does the blood from the GI tract travel to the liver?

Answer 5

hepatic portal vein

Question 6

Where do drugs absorbed sublingually go?

Answer 6

straight to systemic circulation

Question 7

When do drugs reach systemic circulation?

Answer 7

only after passing through the liver once

Question 8

What is an example of a drug whcih need to be absorbed not orally?

Answer 8

glyceryl trinitrate

Question 9

Why is more glyceryl trinitrate needed to achieve the desired effect?

Answer 9

as it is inactivated by the liver when taken orally, need to have higher dose or take sublingually/intravenous

Question 10

When can first pass metabolism (through liver) activates a drug?

Answer 10

simvastatin

less needed

Question 11

Why is it important to consider liver function/health when prescribing?

Answer 11

it metabolises the drug, making it active or inactive.

Question 12

Does non-oral drug admiration have first pass metabolism?

Answer 12

no

Question 13

What can you predict about non-oral drug administration?

Answer 13

plasma levels

Question 14

What are disadvantages of non-oral administration?

Answer 14

allergic reactions more severe

access difficulties/self-medication

drug cost higher

Question 15

What are factors effecting oral absorption?

Answer 15

lipid solubility and ionisation

drug formulation

GI motility

interactions with other substances in gut

GI tract disease (chron’s)

Question 16

What is bioavailability?

Answer 16

proportion of an ingested drug that is available for clinical effect

Question 17

How is a drug distributed?

Answer 17

tissue fluid

Question 18

Is the drug distributed equally to all tissues?

Answer 18

no

example, drugs transported in blood, tissues with high blood flow receive high levels of the drug

Question 19

How does the drug distribute around the body? (2 ways)

Answer 19

plasma proteins and fatty tissue (lipid binding)

Question 20

What tissue absorbs the drug and releases it slowly back into plasma?

Answer 20

fatty tissue

(lipid binding)

Question 21

What are ways plasma proteins effect drugs?

Answer 21

1. inactivate
2. competitive binding warfarin and aspirin

Question 22

What is an example of competitive binding of drugs?

Answer 22

warfarin and aspirin

Question 23

What is phase 2?

Answer 23

preparing the drug for elimination from the body

Question 24

What are examples of phase 1 reactions?

Answer 24

oxidation

reduction

hydrolysis

Question 25

What are phase 2 reactions?

Answer 25

CONJUGATION

• glucuronidation, sulphation, methylation, acetylation …

Question 26

What are examples of drug excretion methods?

Answer 26

renal - urine

liver - bile

lungs - exhale

sweat

saliva

Question 27

What can saliva samples test?

Answer 27

nicotine levels, smoking compliance

Question 28

If the method of secretion of the drug is faulty, e.g. liver disease/renal disease, what should be done?

Answer 28

reduce drug dose

Question 29

What does the blood alcohol elimination curve show?

Answer 29

the level of alcohol at a specific time, you can trace back the predicted levels