Clinical pharmacology

Question 1

what is a drug?

Answer 1

external substance that acts on living tissue to produce a measurable change in the function of that tissue

Question 2

give 3 types of drugs used in dentistry

Answer 2

analgesics - reduce post op pain
local anaesthetics - prevent pain
antimicrobials - prevent infection
anxiolytics - reduce anxiety

Question 3

which messages communicate to ALL tissues?

Answer 3

hormonal

Question 4

which messages give targeted information for specific tissues?

Answer 4

neural

Question 5

what drug can replace missing T3 and T4?

Answer 5

thyroxine

Question 6

how does the sympathetic nervous system affect heart rate?

Answer 6

increases HR via beta receptors

Question 7

how does the parasympathetic nervous system affect heart rate?

Answer 7

decreases heart rate via cholinergic receptors

Question 8

what nervous system causes release of adrenaline?

Answer 8

autonomic sympathetic

Question 9

what nervous system causes release of acetylcholine?

Answer 9

autonomic parasympathetic

Question 10

give an example of a beta agonist drug

Answer 10

adrenaline

Question 11

give an example of a beta blocker drug

Answer 11

atenolol

Question 12

give an example of a cholinergic agonist drug

Answer 12

pilocarpine

Question 13

give an example of a cholinergic blocker drug

Answer 13

atropine

Question 14

give 3 possible drug hazards

Answer 14

• drug interactions
• acute toxic reaction
• anaphylaxis/allergy to drug

Question 15

what drugs should be avoided if on warfarin and/or aspirin?

Answer 15

NSAIDs

Question 16

how long is a prescription valid for?

Answer 16

6 months

Question 17

give examples of some prescribing errors

Answer 17

• the decision to prescribe
• wrong drug
• incorrectly completing prescription
• dose

Question 18

what are the 4 main modes of drug action?

Answer 18

• activation or blocking of receptors
• activating or blocking enzyme function
• facilitating or blocking transport systems
• opening or blocking transport systems

Question 19

what determines the response to drug-receptor interaction?

Answer 19

• the affinity of the drug binding to the receptor

- the occupancy of the drug

Question 20

describe how an agonist works

Answer 20

binds to receptor and activates it to produce natural response

Question 21

describe how a partial agonist works

Answer 21

the drug/receptor effect is more difficult to produce than with an agonist

Question 22

describe how an antagonist works

Answer 22

they bind to the receptor and do not activate them

• competitive or non-competitive
• reversible antagonists effect can be reduced by increasing agonist concentration
• irreversible antagonist binds and reduces available receptors for agonist

Question 23

how can drugs change enzyme action?

Answer 23

• competitive substrate antagonism

- non-competitive substrate inhibition

Question 24

give a drug that affects ion channels

Answer 24

local anaesthetic

Question 25

what are pharmacokinetics?

Answer 25

what the drug does to the body

Question 26

what are pharmacodynamics?

Answer 26

what the body does to the drug

Question 27

what are disadvantages of oral administration?

Answer 27

- first pass metabolism - GI disease can reduce surface area for absorption - gastric acid can destroy drug - food can interact

Question 28

where does first pass metabolism take place?

Answer 28

liver

Question 29

where does GI tract blood drain to?

Answer 29

hepatic portal vein which drains to the liver

Question 30

what is first pass metabolism?

Answer 30

- liver metabolises drug and the drug only reaches systemic circulation after passing through the liver - FPM can activate or inactivate the drug

Question 31

where can the drug directly enter the systemic circulation?

Answer 31

rectal and sublingual veins

Question 32

why is glyceryl tri-nitrate administered sublingually?

Answer 32

FPM inactivates the GTN and very little enters systemic circulation. giving sublingually bypasses hepatic portal system

Question 33

what is the effect of liver disease on drug metabolism?

Answer 33

reduced metabolism will lead to drug accumulation and toxicity

Question 34

give an example of a drug activated by FPM

Answer 34

valaciclovir produces aciclover in liver so less doses are needed than aciclover

Question 35

advantages of intravenous and intramuscular

Answer 35

no drug lost as no FPM | rapid onset

Question 36

disadvantages of intravenous and intramuscular

Answer 36

severe allergic reactions high cost short duration of action

Question 37

transdermal and subcutaneous advantages

Answer 37

no FPM | prolonged action

Question 38

transdermal and subcutaneous disadvantages

Answer 38

slow onset due to low blood flow

Question 39

what is bioavailability?

Answer 39

the proportion of an injected drug available for clinical effect

Question 40

what may affect bioavailability?

Answer 40

``` route of administration dosage food in gut poor absorption FPM ```

Question 41

how does blood flow affect drug distribution?

Answer 41

drug is distributed pending on blood flow, tissues with the highest blood flow receive highest level of drug

Question 42

how are drugs distributed?

Answer 42

drug dissolves in blood and is transported bound to plasma protein carriers such as albumin

Question 43

what is the most common drug metabolism pathway?

Answer 43

p450 mono-oxygenate system

Question 44

describe the 2 main reactions of drug metabolism

Answer 44

phase 1 changes the drug - oxidation, hydrolysis, reduction phase 2 - conjugation e.g. sulphation, methylation

Question 45

what can cause issues with excretion of drugs?

Answer 45

- renal disease will affect renal blood flow and therefore renal ability to excrete drugs - reduce dose - liver disease can lead to liver failure, reduce doses

Question 46

what is the plasma half life of a drug?

Answer 46

the time taken to eliminate half the drug

Question 47

what does it mean if a drug follows first order kinetics?

Answer 47

drug metabolism increases as drug concentration increases | excretion by passive diffusion only

Question 48

what does it mean if a drug follows zero order kinetics?

Answer 48

drug metabolism is at a fixed rate, not affected by drug concentration can lead to accumulation if saturation exceeded