Infections Physiology And Pharmacology

Question 1

Answer 1

Question 2

Answer 2

Question 3

Answer 3

Question 4

What antibiotic, normally used as second line agent for UTI, causes an increase INR of warfarin. Why does it occur.

Answer 4

Trimethoprim-sulfamethoxazole.

70% Sulfamethoxazole and 44% trimethoprim is bound to warfarin displacing warfarin from protein binding site. Also inhibits S-warfarin metabolism.

Question 5

What are the four C’s antibiotic responsible for C.difficile.

Answer 5

Question 6

What antibiotic when administered with alcohol causes a disulfiram like reaction.
(a) Metronidazole
(b) Doxycycline
(c) Clarithromycin
(d)Flucloxacillin
(e) Erythromycin

Answer 6

(a) Metronidazole

Question 7

What antibiotic when co-administered with Rivaroxaban increases risk of bleed.
(a) Metronidazole
(b) Doxycycline
(c) Clarithromycin
(d)Flucloxacillin
(e) Erythromycin

Answer 7

(e) Rivaroxaban is a CYP3A4 substrate and macrocodes are inhibitors.

Question 8

What antibiotic when co-administered with NSAIDs increases the risk of seizures.

(a) Metronidazole
(b) Doxycycline
(c) Ciprofloxacin
(d) Amoxicillin
(e) Erythromycin

Answer 8

(c) Ciprofloxacin

Question 9

Patient presents with QT prolongation. What is the likely reason for this presentation.

(a) Insulin + Meropenem
(b) Clarithromycin + Amiodarone
(c) Fluoxetine + Amoxicillin
(d) Isotretinoin + Doxycycline

Answer 9

(b) Macrolide and Amiodarone are known to prolong QT and when together they increase the risk of QT prolongation.

Question 10

Patient with history of Ulcerative colitis presents to your word requiring antibiotics for hospital acquired pneumonia. She has no penicillin allergy. What agent would you avoid.
(a) Co-Amoxiclav
(b) Levofloxacin
(c) Vancomycin
(d) Linezolid

Answer 10

(a) Co-amoxiclav as there is increased risk of toxic mega colon.

Question 11

Patient R has been prescribed loop diuretic to manage peripheral oedema secondary to Heart failure. You finish you ward rounds and realise Patient R has been started on Vancomycin for MRSA. What are your concerns here.

Answer 11

Increased risk of nephrotoxicity when vancomycin is co-administered with loop diuretics.

Question 12

Patient Lina presents to you wards with tinnitus and you check her drug history, what is the likely causative agent.
(a) Co-Amoxiclav
(b) Levofloxacin
(c) Vancomycin
(d) Linezolid

Answer 12

(c) Vancomycin.

Question 13

60 year old patient presents to your ward and the doctor has prescribed Ciprofloxacin for management of respiratory infection. What are you concerns.

Answer 13

Increased risk of tendinopathy in patient age >60.

Question 14

Which antibiotics on this list can you take on an empty stomach.

(a) Azithromycin capsules
(b) Metronidazole
(c) Amoxicillin
(d) Clarithromycin

Answer 14

(a) Azithromycin capsules

Question 15

Which antibiotics should patient take with or just after food.
(a) Metronidazole
(b) Amoxicillin
(c) Ciprofloxacin
(d) Doxycycline
(e) Nitrofurantoin

Answer 15

(a) + (b) + (e) = mitagate GI upset, improve absorption. The rest can be take on an empty stomach.

Question 16

Which antibiotic needs to be taken with full glass of water.
(a) Metronidazole
(b) Amoxicillin
(c) Ciprofloxacin
(d) Doxycycline
(e) Nitrofurantoin

Answer 16

(a) + (d) = to prevent risk of esophagitis.

Question 17

Gentamicin mechanism of action

Answer 17

Irreversible inhibitor of 30s ribosome.

Question 18

True or false:
a) Gentamicin exhibits concentration dependent killing.
b) Vancomycin shows time dependent killing.

Answer 18

Both true

Question 19

Select the best option from the list provided.
a. Gentamicin
b. Vancomycin
c. Penicillin V
d. Co-Amoxiclav
e. Clarithromycin

1. A patient who has an infection which has grown to Pseudomonas aeruginosa and is allergic to penicillin. The patient’s calculated creatinine clearance is 70 mL/min
2. A 16-year-old patient who has developed tonsillitis. Which agent should be prescribed initially, as empirical treatment.

Answer 19

1. a. Gentamicin
2. c. Penicillin V

Question 20

What microorganism cause bacterial tonsillitis

Answer 20

Stept. A (gram +)

Question 21

What antibiotics cover Strept. A infections.

Answer 21

1.Phenoxymethylpenicillin used for the treatment of strep throat, otitis media…. (Penicillin V)
Also: TMP-SMX, macrolides….

Question 22

What antibiotic has broad spectrum activity against Pseudomonas Aurginosa if patient is allergic to penicillin.

Answer 22

Gentamicin (aminoglycosides)

Question 23

First Line and second line agent for Otitis media

Answer 23

Amoxicillin
Clarithromycin

Question 24

What causes Otitis media

Answer 24

Strept. pneumonia (gram +)

Question 25

What antibiotics have activity against Strep.pneumonia

Answer 25

Third gen cephalosporins
Aminopenicillin
Fluoroquinolone’s

Question 26

Which ONE of the following agents in NOT suitable for the management of a urinary tract infection.
(a) Nitrofurantoin
(b) Ciprofloxacin
(c) Trimethoprim
(d) Teicoplanin

Answer 26

(d) Teicoplanin

Question 27

Which antibiotics have activity against enterococci.

Answer 27

Flouroquinolones (ciprofloxacin)
Nitrofurantoin
Trimethoprim.