Penicillin

Question 1

What class is penicillin

Answer 1

beta-lactam

Question 2

what does penicillin interfere with

Answer 2

cell wall

Question 3

what cell wall synthesis inhibitors are there?

Answer 3

cephalosporins, carbapenums and monobactams

Question 4

is penicillin bactericidal or non bactericidal

Answer 4

bactericidal

Question 5

3 mechanisms of action for penicillin

Answer 5

inhibits cross linking peptides, inactivates autolysis inhibitors and rapidly dividing organisms

Question 6

Penicillin spectrum of activity

Answer 6

narrow spectrum, most gram +ve cocci, gram +ve bacilli, some gram -ve cocci and anaerobic potential

Question 7

Penicillin kill characteristics

Answer 7

time dependant killing

Question 8

penicillin preparations

Answer 8

Penicillin V (Benzylpenicillin), Penicillin G (Phenoxymethylpenicillin)and Procaine/ Benzathiane penicillin

Question 9

Benzylpenicillin (G) pharmacology

Answer 9

oral absorption - 20%, half life - 30 min, peak serum - 2ug/ml

Question 10

Phenoxymethylpenicllin (V) pharmacology

Answer 10

oral absorption - 60-73%, half life - 30 -45 min, peak serum - 4ug/ml

Question 11

Penicillin indications

Answer 11

Pen G reserved for severe infections, oral route compromise, beware of beta lactase producing bacteria

Question 12

Penicillin hypersensitivity

Answer 12

common - 8%
maculopapular or urticarial rash
20-49 years

Question 13

Penicillin immediate reaction

Answer 13

severe, 0.005 to 0.015%

Question 14

Immediate reaction symptoms

Answer 14

nausea, vomitting, pruritus, erythema/urticaria/rash, wheeze

Question 15

delayed reaction

Answer 15

vesicular, maculo-papular, bullous, urticarial, scarlatiniform

Question 16

Hypersensitivty risk factors

Answer 16

multiple drug allergies, atopic disease, asthma, allergic rhinitis, nasal polyps, skin testing

Question 17

Hypersensitivity on re-exposure percentage?

Answer 17

15-40%

Question 18

Length of time serum IgE antibodies retained?

Answer 18

10-100 days

Question 19

When do you use the yellow card

Answer 19

adverse drug reaction

Question 20

Penicillin V - dose, duration, frequency and route

Answer 20

500mg, 6 hourly, 3-5 days and oral

Question 21

Penicillin G- dose, duration, frequency and route

Answer 21

1.2g, 6 hourly, 3-5 days, IV

Question 22

3 main evasion mechanisms

Answer 22

reduced binding to penicillin binding protein, hydrolysis of the drug beta lactase enzymes and development of a tolerance by disabling their autolysis mechanism

Question 23

Penicillin interactions

Answer 23

antagonism, NSAID, warfarin?, methotrexate, oral contraceptive

Question 24

common unwanted effects

Answer 24

diarrhoea, nausea and skin rash

Question 25

uncommon unwanted effects

Answer 25

vomitting, urticaria, arthralgia

Question 26

very rare unwanted effects

Answer 26

mucocutaneous candidiasis, hypersensitivity reactions , severe renal failure

Question 27

alternatives

Answer 27

metronidazole, clarithromycin, erthryomycin, clindamycin

Question 28

resistance

Answer 28

beta lactase