penicillins

Question 1

what is penicillins drug class

Answer 1

Penicillins/Beta lactams

Question 2

what is penicillins mechanism of action

Answer 2

cell wall inhibitor

Bactericidal

Inhibits cross linking peptides

Inactivates autolysin inhibitors stopping the cells ability to heal the cell wall

Question 3

why is penicillin best for rapidly dividing organisms

Answer 3

as more cell wall synthesis so more opportunity to disrupt it

Question 4

what is penicillins spectrum

Answer 4

narrow spectrum

Question 5

what is penicillins killing mechanism

Answer 5

Time dependant killing mechanism - requires blood concentration to be held in order to kill as takes time to work

Question 6

what is penicillins half life

Answer 6

30mins

Question 7

what is pen G used for

Answer 7

serious infections, IV, when oral route compromised

Question 8

what is pen V used for

Answer 8

oral infections, acute sinusitis

Question 9

2 contraindications of penicillins

Answer 9

○ Pt who have received penicillin recently should be given alternative
Allergy

Question 10

when does type 1 hypersensitivity occur?

Answer 10

immediately

Question 11

what happens in type 1 hypersensitivity

Answer 11

IgE Mast cell degranulation and histamine release

Question 12

signs/symptoms of type 1 hypersensitivity 7

Answer 12

Nausea/vomiting, itchiness, rash, laryngeal oedema, wheeze, hypotension, bronchospasm

Question 13

when does type 2 hypersensitivity occur

Answer 13

delayed

Question 14

what happens in type 2 hypersensitivity

Answer 14

IgG or IgM mediated

Question 15

signs/symptoms of type 2 hypersensitivity

Answer 15

Blood dyscrasias, haemolytic anaemia, leukopenia, thrombocytopenia, aplastic anaemia

Question 16

when is type 2 hypersensitivity not contraindicated? why?

Answer 16

not contra-indicated if it’s the best choice e.g. life threatening

Short lived

Question 17

risk factors for penicillin allergy 4

Answer 17

Asthma, atopic disease, allergic rhinitis, nasal polyps

Question 18

side effects of penicillin

Answer 18

○ Diarrhoea, nausea, rash
Toxicity in renal failure

Question 19

interactions of penicillin

Answer 19

Warfarin - may affect INR
Methotrexate - reduce excretion

Question 20

dose of Pen v:
?mg
?hourly
?days
route of administration?
loading dose

Answer 20

500mg
6hrly
3-5days
oral
yes

Question 21

is there resistance to penicillin?

Answer 21

beta lactamase producing bacteria

Question 22

alternatives to penicillin 4

Answer 22

Metronidazole, clarithromycin, erythromycin, clindamycin

Question 23

penicillin clearance

Answer 23

renal