Antibiotics

Question 1

Unnecessary/Inappropriate Antibiotic prescribing leads to emergence of….

Answer 1

Bacteria Resistance

Question 2

How do bacterium acquire antibiotic resistance?

Answer 2

• Resistance gene from environment
• DNA exchange with other bacteria
• From bacteriophage (Virus)

Question 3

Infection with penicillinase-producing bacteria is most likely resistant to…..?

Answer 3

Benzylpenicillin
Substrate to Penicillinase

Question 4

What narrow spectrum antibiotic is used to treat Strep Throat (G+)?

Answer 4

Penicillin V
Does not produce GI side effects like Amoxicillin

Question 5

What antibiotic is only effective for infection of G+ bacteria??

Answer 5

Vancomycin
- Unable to pass outer layer of G- cell membrane

Question 6

Which β-lactam Abx inhibits peptidoglycan cross linking but only effective against G-

Answer 6

Aztreonam
- Inhibits serine beta-lactamases enzyme that inactivates beta-lactam ring

Question 7

Which antibiotic should be avoided with alchol??

Answer 7

Metronidazole
Inhibits aldehyde dehydrogenase> causes acetaldehyde to build up in bloodstream
High Acetaldehyde = Liver damage

Question 8

What antibiotic is contraindicated in 4 year old with pneumonia?

Answer 8

Doxycycline-

Tetracyclines bind to calcium which affects bone development + discoloured teeth

Question 9

Which antibiotics increase the QT interval on ECG, which can cause cardiac arrhythmias??

Answer 9

Clarithromycin and Ciprofloxacin

Clarithromycin- inhibits the rapidly activating delayed rectifier potassium current (IKr) in cardiac myocytes
Ciprofloxacin -Fluoroquinolones prolong QT interval by blocking potassium channels

Question 10

What antibiotic cause tinnitus and dizziness??

Answer 10

Gentamicin

Monitor to ensure working within Therapeutic window

Question 11

Which antibiotics require measurement of drug levels in plasma?

Answer 11

Vancomycin and Gentamicin

Question 12

What antibiotic is used to treat uncomplicated UTI??

Answer 12

Nitrofurantoin-

Converted by bacterial nitroreductases to electrophilic intermediates which inhibit the citric acid cycle and synthesis of DNA, RNA, and protein.

Question 13

What antibiotic is used to treated erythematous rash following amoxicillin use??

Answer 13

Clarithromycin
2nd line used in Penicillin allergies

Question 14

Which antibiotics can promote C.Difficile colitis?

Answer 14

Oral Broad Spectrum