Antibiotics

Question 1

Where are MRSA swabs taken from

Answer 1

• nose, throat
• groin
• armpits
• wounds
• entry sites for invasive devices eg stoma, catheter
• umbilicus (infants only)

Question 2

Bacteria that causes a fruity smell on culture

Answer 2

Pseudomonas aeruginosa

Question 3

Alcohol can induce vomiting if consumed within 48 hours of taking what antibiotic

Answer 3

Metronidazole

Question 4

What a/b(s) are used to treat MRSA

Answer 4

• vancomycin
• teicoplanin

(prontoderm to get off skin)

Question 5

What a/b(s) are used to treat anaerobic bacteria

Answer 5

Metronidazole

add to broad spectrum cephalosporin

Question 6

Definition of clean surgery

Answer 6

No breach of hollow organ

Question 7

Definition of clean contaminated surgery

Answer 7

Hollow viscus breached

eg cholecystectomy

Question 8

Definition of contaminated surgery

Answer 8

eg appendectomy, bowel resection

Question 9

Definition of dirty surgery

Answer 9

Pus present in operating site

eg perforated colon

Question 10

What a/b to give asymptomatic contacts of syphilis patient

Answer 10

Doxycycline

14 days

Question 11

What a/b to give purulent conjunctivitis

Answer 11

Chlormaphenicol eye drops

Question 12

What a/b to give otitis externa

Answer 12

Topical tx (see BNF)

Flucloxacillin if spreading cellulitis

Question 13

What a/b to give otitis media

Answer 13

NOTE: usually viral, no need a/b

Ampicillin/Amoxicillin if no improvement after 72h

Question 14

What a/b to give sinusitis

Answer 14

NOTE: only give if persistent symptoms + purulent discharge for 7 days

Ampicillin/Amoxicillin
7 days

Question 15

Class and mode of action of the following a/b:

Vancomycin

Answer 15

Glycopeptide

```
Prevents transglycosylation
Inhibits cell wall integrity
~~~

Question 16

Class and mode of action of the following a/b:

Gentamycin

Answer 16

Aminoglycoside

Binds irreversibly to 30s subunit
Ribosome cannot fit mRNA
Inhibits protein synthesis

Question 17

Class and mode of action of the following a/b:

Erythromycin

Answer 17

Macrolide

Binds reversibly to 50s subunit
Blocks P site on ribosome
Inhibits protein synthesis

Question 18

Class and mode of action of the following a/b:

Doxycycline

Answer 18

Tetracycline

Binds reversibly to 30s subunit
Stops binding of tRNA to mRNA
Inhibits protein synthesis

Question 19

Class and mode of action of the following a/b:

Clindamycin

Answer 19

Similar to macrolides but separate class

Binds reversibly to 50s subunit
Blocks P site on ribosome
Inhibits protein synthesis

Question 20

Mode of action of the following a/b:

Metronidazole

Answer 20

Nitroimidazole

Inhibits nucleic acid synthesis

Question 21

Mode of action of the following a/b:

Nitrofurantoin

Answer 21

Damages DNA

Question 22

Mode of action of the following a/b:

Trimethoprim

Answer 22

Blocks dihydrofolate reductase

Folate inhibitor
cannot be given to pregnant women

Question 23

Class and Mode of action of the following a/b:

Sulfasalazine

Answer 23

Sulfonamides

Blocks dihydrofolate synthase

Folate inhibitor
(?safe for pregnant women)

Question 24

Which classes are beta lactams?

Answer 24

• penicillins
• cephalosporins
• carbapenems
• monobactams

Question 25

How do beta lactams work as a/b?

Answer 25

Disrupt cell wall synthesis

Question 26

Name example(s) of beta lactamase resistant a/b

Answer 26

- flucoxacillin | - methylcillin

Question 27

Define bacteriocidal vs bacteriostatic

Answer 27

Bacteriocidal = kills bacteria Bacteriostatic = stops replication of bacteria

Question 28

Examples of classes of bacteriocidal a/b

Answer 28

- penicillins - cephalosporins - carbapenams - monobactams - glycopeptides eg vancomycin - metronidazole - nitrofurantoin

Question 29

Examples of classes of bacteriostatic a/b

Answer 29

INHIBIT FOLATE SYNTHESIS - trimethoprim - sulfonamides INHIBIT PROTEIN SYNTHESIS - clindamycin - macrolides - tetracyclines - aminoglycosides

Question 30

Which a/b might cause Steven Johnson syndrome

Answer 30

Trimethoprim

Question 31

Which a/b might cause Red Man syndrome

Answer 31

Vancomycin | and other glycopeptides

Question 32

Describe Steven Johnson syndrome

Answer 32

Type 4 hypersensitivity reaction Fever + flu-like symptoms then skin blisters and peels

Question 33

Describe Red Man syndrome

Answer 33

Red rash

Question 34

Severe complications of Steven Johnson syndrome

Answer 34

Multiple organ failure

Question 35

Severe complications of Steven Johnson syndrome

Answer 35

- Multiple organ failure | - scar tissue inside eyelids leading to impaired vision

Question 36

How to avoid Red Man syndrome

Answer 36

Infuse vancomycin slowly (over >60min interval)

Question 37

Which a/b inhibit cell wall synthesis

Answer 37

- penicillins - cephalosporins - carbapenems - monobactams - glycopeptides eg vancomycin

Question 38

Which a/b inhibit protein synthesis

Answer 38

- tetracyclines - aminoglycosides - macrolides - clindamycin

Question 39

Which a/b inhibit folate synthesis

Answer 39

- trimethoprim | - sulphonamides

Question 40

Which a/b inhibit DNA synthesis

Answer 40

- metronidazole - quinolones (inhibit DNA gyrase) - nitrofurantoin (damages DNA)

Question 41

Main side effects of gentamycin

Answer 41

1. ototoxic | 2. nephrotoxic

Question 42

Main side effects of co-trimoxazole (trimethoprim + sulfamethoxazole)

Answer 42

1. nausea 2. nephrotoxic, hepatotoxic 3. Steven Johnson syndrome 4. Bone marrow suppression