Antibiotics

Question 1

Adverse drug reaction

Answer 1

response to drug which is unintended and which occurs at doses normally used for prophylaxis or therapy - not allergic reaction

Question 2

If you have a true penicillin allergy, you will not be able to take what other classes of antibiotics? (3)

Answer 2

cephalosporins,
carbapenems,
aztreonam,
all have beta lactam ring

Question 3

CNS bacterial infection could be which of the following bugs: 
E.coli, 
H. influenzae, 
Strep pneumonia, 
s.aureus, 
c.difficile, 
legionella, 
s.epidermis

Answer 3

Strep pneumonia

Question 4

Resp infection could be which of the following bugs: 
E.coli, 
H. influenzae, 
Strep pneumonia, 
s.aureus, 
c.difficile, 
legionella, 
s.epidermis

Answer 4

H. influenzae,
strep pneumonia,
legionella

Question 5

Gut infection could be which of the following bugs:
E.coli, 
H. influenzae, 
Strep pneumonia, 
s.aureus, 
c.difficile, 
legionella, 
s.epidermis

Answer 5

c.diff

Question 6

Urinary infection could be which of the following bugs:
E.coli, 
H. influenzae, 
Strep pneumonia, 
s.aureus, 
c.difficile, 
legionella, 
s.epidermis

Answer 6

E.coli

Question 7

Skin infection could be which of the following bugs: 
E.coli, 
H. influenzae, 
Strep pneumonia, 
s.aureus, 
c.difficile, 
legionella, 
s.epidermis

Answer 7

S.aureus

Question 8

Staph epidermis usually never really causes infection except for when?

Answer 8

When prosthetic material

Question 9

What antibiotic for strep pneumonia in CNS?

Answer 9

a cephalosporin
OR,
amoxicillin at high dose

Question 10

What antibiotic for haemophilus influenzae in lungs?

Answer 10

Mild: amoxicillin if allergic IV levofloxacin,
Severe: Co-amoxiclav + PO doxycycline, if allergic IV levofloxacin

Question 11

What antibiotic for c.diff infection in gut?

Answer 11

1st line: oral vancomycin,

metronidazole if no vancomycin

Question 12

What antibiotic for uncomplicated e.coli infection in urinary tract?

Answer 12

1st line nitrofurantoin,

2nd trimethoprim

Question 13

What antibiotics for staph aureus

Answer 13

flucloxacillin

or doxycycline

Question 14

UTI catheterised patient investigation

Answer 14

urine culture,

blood culture if seems septic,

Question 15

UTI catheterised patient management (initial therapy with and w/o penicillin allergy, step down therapy)

Answer 15

currently IV amoxicillin & gentamicin,
Penicillin allergy: co-trimoxazole + gentamicin,
Step down therapy: PO co-trimoxazole

Question 16

UTI catheterised patient improves with IV amoxicillin & gentamicin, e.coli report comes back resistant to amox. Why is step down therapy co-trimoxazole and not nitrofurantoin?

Answer 16

Nitrofurantoin is only active once concentrated in bladder, not effective in bloodstreem/kidneys so once complicated e.g. fever, sepsis, vomiting, flank pain then nitrofurantoin doesn’t work.

Question 17

UTI catheterised patient improves with IV amoxicillin & gentamicin, e.coli report comes back resistant to amox. Why is step down therapy co-trimoxazole and not to continue IV gentamicin?

Answer 17

IV gentamicin carries risks of nephrotoxicity and ototoxicity,
Also IV carries risk of infection of staph aureus from cannula.

Question 18

Coag negative Staph epidermidis treatment?

Answer 18

IV vancomycin (fluclox doesn’t work against coagulase negative staph)

Question 19

Moraxella catarrhalis associated with who in CAP

Answer 19

COPD exacerbations in particular

Question 20

Perforated diverticulum with signs of sepsis - pathogens & antibiotics

Answer 20

Pathogens: polmicrobial coliforms, anaerobes & eneteroccocci,
Antibiotics: IV amoxicillin + metronidazole + gentamicin

Question 21

Profuse diarrhoea, abdo pain, vomiting. Recent treatment with co-amoxyclav for resistant UTI. Likely pathogen and antibiotics?

Answer 21

Pathogen: likely c.difficile after a 4c antibiotic,
Antibiotics: 1st line oral vancomycin, 2nd line metronidazole

Question 22

Presentation RUQ pain, fevers, N&V. RUQ and positive murphy’s sign. Likely diagnosis, pathogen and antibiotics?

Answer 22

Diagnosis: cholangitis, cholecystitis
Likely pathogens: coliforms, anaerobes and enterococci,
Antibiotics: IV amoxicillin + metronidazole + gentamicin

Question 23

Endocarditis native valve acute: bug and management

Answer 23

Staph aurues, take 2 sets blood cultures & start antibiotics within 1 hour, flucloxacillin IV

Question 24

Endocarditis native valve subacute: bugs and management

Answer 24

Strep viridans, enterococci,
3 sets blood cultures 6 hours apart,
Amoxicillin IV + gentamicin

Question 25

Prosthetic valve: bug & management

Answer 25

Coagulase negative staph: staph epidermidis,

Vancomycin IV & gentamicin

Question 26

Step down therapy for peritonitis/biliary tract/intra abdo infection?

Answer 26

Oral co-trimoxazole and metronidazole

Question 27

Gentamicin concern?

Answer 27

Nephrotoxicity

Question 28

Gentamicin management of concerns with using this drug?

Answer 28

Limit duration: 72 hours then approval required, only 24 hours if renal concern,
Monitor renal function daily

Question 29

Ciprofloxacin side effects? (4)

Answer 29

C.diff,
Tendonitis,
Interacts with epileptic drugs so lowers seizure threshold,
QT interval