Pharmacology

Question 1

what are local anaesthetics used for

Answer 1

to reduce awareness of pain

Question 2

how do local anaesthetics work

Answer 2

by blocking ion channels, preventing propagation of AP

Question 3

give examples of antibiotics used in dentistry

Answer 3

amoxycillin

Question 4

give examples of anti-virals

Answer 4

aciclovir

Question 5

give examples of anti fungals

Answer 5

topical - nystatin systemic - fluconazole

Question 6

how do anti-inflammatories work

Answer 6

by inhibiting arachidonic acid binding to either COX 1 or 2, prevents prostaglandin production

Question 7

what are common side effects with NSAID

Answer 7

increased risk of bleeding, increased gastric ulcer production, exacerbate asthma

Question 8

what causes the side effects caused by NSAID

Answer 8

inhibiting COX 1 or 2 results in blocking thromboxane production, prevents platelet aggregation - more prone to bleeding

Question 9

what drug interacts with aspirin and ibruprofen

Answer 9

warfarin

Question 10

what is the difference between aspirin and ibruprofen

Answer 10

aspirin has much more severe side effects, aspirin blocks COX 1, ibruprofen blocks COX 2

Question 11

what is diclofenac

Answer 11

an NSAID that can only be prescribed with prescription

Question 12

what is a positive of using aspirin

Answer 12

if people have heart problems, blood is thinner

Question 13

how do corticosteroids work

Answer 13

inhibits capillary permeability, bradykinin formation and white blood cell migration, suppresses inflammation but doesnt target the cause

Question 14

give examples of corticosteroids

Answer 14

beclomethasone - inhaler, prednisolone - oral, hydrocortisone - topical

Question 15

what are the side effects of corticosteroids

Answer 15

high blood pressure, diabetes, weight gain, adrenal suppression, gastric ulceration

Question 16

what drugs are used in sedation

Answer 16

nitrous oxide and diazepan

Question 17

how is nitrous oxide administered

Answer 17

inhaled as a gas but should be avoided in pregnancy - interacts with folic acid

Question 18

name 3 ways in which a drug can exert its effect on the body

Answer 18

activating an ion channel, activating/inhibiting an enzyme, coupled to G-protein receptors

Question 19

what is the result of activating a g protein

Answer 19

this activates an enzyme which results in production of a second messenger, acts within the cell to bring about change e.g. protein production

Question 20

give an example of a drug altering ion channels

Answer 20

local anaesthetic blocks ion channels to prevent AP conduction

Question 21

give an example of a drug that alters enzyme activity

Answer 21

aspirin, inhibits COX 1 preventing arachiodonic acid from binding

Question 22

what effects a drugs efficacy

Answer 22

affinity and occupancy

Question 23

when might a drugs affinity for a receptor be lowered

Answer 23

if the drug is only a partial agonist, doesnt fit as well into the binding site so wont work as well

Question 24

what can be done to increase the efficacy of partial agonists

Answer 24

increase the concentration, increases occupancy, however, doesnt work for all drugs

Question 25

name different types of antagonists and give explanations

Answer 25

reversible - unbinds to the receptor, leaving it unchanged
irreversible - permanent change to receptor
competitive and non-competitive - depends on whereabouts it exerts it’s effect

Question 26

what are the phases of drug action

Answer 26

absorption, clinical effect, metabolism, excretion

Question 27

what are the routes of administration for drugs

Answer 27

oral, subcutaneous, intravenous, intramuscular

Question 28

what are the advantages of oral administration

Answer 28

socially acceptable

Question 29

what are the disadvantages of oral administration

Answer 29

slow onset, variable absorption, unpredictable bioavailability, must have functioning GI tract and liver, drug must be lipophillic (unionised) to get through the membrane but then active part is ionised

Question 30

describe first pass metabolism

Answer 30

oral drugs go through the GI tract and into hepatic portal vein into the liver before reaching the systemic circulation. therefore, before they reach the area they are targeting, a proportion of the drug is already lost. makes us unsure of how much drug is actually reaching the desired area and also a bigger dose is required

Question 31

what routes of administration are unaffected by first pass metabolism

Answer 31

injection via muscle or vein, sublingual or rectal absorption

Question 32

what organs must be working well for drugs to be given

Answer 32

liver and kidney

Question 33

what is bioavailability

Answer 33

the proportion of drug exerting the clinical effect

Question 34

what factors affect bioavailability

Answer 34

absorption, first pass metabolism, dosage, destruction in gut

Question 35

how is the drug distributed amongst the body

Answer 35

lipid binding - accumulation and slow release

plasma protein binding

Question 36

how does plasma protein binding work in drug distribution

Answer 36

drug bound to plasma protein is inactive, however, it frees up more space in the plasma to carry more drug. the drug in the plasma free is active and available. when this diffuses out to tissue, the drug unbinds from plasma protein and moves into plasma to be available.

Question 37

give an example of drug interaction via plasma protein binding

Answer 37

aspirin and warfarin - one has a higher affinity to the plasma protein so this binds, making the other available

Question 38

describe the 2 phases of drug metabolism

Answer 38

phase 1 - inactivation of drug via oxidation, hydrolysis, reduction
phase 2 - conjugation with a molecule being excreted

Question 39

describe first order kinetics in terms of drug clearance

Answer 39

the amount of drug cleared is proportional to the concentration of drug. is a passive process, drug has a half life - for a given time half the concentration is cleared

Question 40

describe zero order kinetics in terms of drug clearance

Answer 40

the amount of drug cleared in a given time is fixed. is an active process involving enzymes. when the enzyme is saturated, unable to clear any more drug, has to wait until space becomes available

Question 41

how can plasma toxicity occur

Answer 41

if there is high levels of drug in the plasma and not enough being cleared, give more drug and building on plasma levels already there

Question 42

how can drugs be excreted

Answer 42

through the kidney and liver then passed through GI tract, or through lungs with breathing or sweat

Question 43

what is meant by a dosing schedule

Answer 43

knowing when and how much drug to give for the clinical effect to be seen but preventing plasma toxicity