PHARMACUTICALS

Question 1

How does warfarin work?

Answer 1

1. clotting factors 2,7,9,10 production in the liver depends on profactors being converted to active factors

profactors-> active factors occurs by carboxylation
-requires presence of reduced vitamin K

-Vitamin K undergoes conversion from oxidise vitamin K -> Reduced vitamin K via an enzyme reductase.

2. Warfarin acts of vitamin K reductase: reducing levels of reduced vitamin K so clotting factors cannot be produced
3. no more active clotting factors are produced

Question 2

What is meant by isomerisation of warfarin

Answer 2

s isosomer form and r-form
s is x3 folds greater than r-form

Question 3

why is there a lag period in iNR after changing dose & impact as a dentist

Answer 3

warfarin inhibits production of clotting factors rather than activitiy of current circulating factors so current needs to be consumed or produced

impact:
-stopping warfarin 2 days before surgical procedure
- stopping increase risk of embolism/ thromosis

Question 4

What is NSAIDs effect on warfarin

Answer 4

NSAIDS: also antiplatelet- inhibit platelet activation

Question 5

What are the effects of adrenaline on the body

Answer 5

smooth muscle/ striated muscle contraction:
Islet of langerhans
lungs: smooth muscle bronchodilation
raise BP,
Raise blood glucose
raise plasma

increase SV, CO, HR
decrease airway resistance

Question 6

How do NSAIDs work

Answer 6

phospholipids-> arachdonic acid->
Cycloxoygenase pathway: prostagladins/ thromboxane A2

Lopoxygenase: leukotrienes -> causes bronchoconstriction

Question 7

How does ibuprofen work

Answer 7

reversibly interfers with cox1 and cox2 pathway

Question 8

How does aspirin work

Answer 8

irreversible acetylates COX1. and COX2

Question 9

What is Coamoxiclav

Answer 9

mixture of amoxicillin and clavulanic acid- effective against B-lactamase

Question 10

What is Augmentin

Answer 10

Co- Amoxiclav - mixture of amoxicllin and clavulanic acid

Question 11

How does cephlasporins work

Answer 11

B-lactam ring
-incorporates in bacterial cell wall weakening it
- loss of cell wall integrity & death of bacteria

Question 12

what type of spectrum is penicillin

Answer 12

Narrow specturm Gram +ve

Question 13

How is Benzylpenicillin (Pen G) administered

Answer 13

broken down by acid so is ineffective if taken orally and must be given by Intramusuclar injection

Question 14

What is phenoxymethyl

Answer 14

Pen V
Acid-stable taken orally

Question 15

How is pencillin excreted

Answer 15

kidneys
- high serum concentrations elevated in patients with renal failure

Question 16

How doe tetracycline, macrolide and aminglycosides work

Answer 16

inhbiti ribosomes- affect ribosomes so affect bacterial protein production

Question 17

How does erthromycin work

Answer 17

inhibit transfer from tRNA to peptide chain

Question 18

How does tetracycline work

Answer 18

inhibit transfer of tRNA to ribosome

Question 19

How does amingolgycosides work

Answer 19

interfer with reading of mRNA

Question 20

Why is tetracycline not prescribed to children

Answer 20

colour discolouration

Question 21

side effects of aminglycosides/ tetracyclines

Answer 21

• tooth discolouration
• hearing loss

Question 22

can tetracyclines be given to pregnant women

Answer 22

NO

Question 23

Can gentamycin be given to pregnant/ breast feeding women

Answer 23

NO- otoxicity

Question 24

How does metrondiazole work

Answer 24

active against anaerobic bacteria
- diffuses into bacterial/ protozoal cell-> reduced by removal of single electron
- binds to DNA prevents repair and replication

• variety of bacterial and protozoal infections

Question 25

where is metronidazole cleared

Answer 25

kidneys

Question 26

what are side effects of metrondiazole

Answer 26

interact with alcohol as has dissulfiramin-like action on pts who drink alcohol