Choosing Antibiotics

Question 1

Definition of an iterative process

Answer 1

Doing something again and again - e.g. an iterative process of testing and retesting to come to a single diagnosis

Question 2

Step-wise process of antibiotic selection

Answer 2

1: Determine the infection diagnosis (or working/differential diagnosis)
2: Identify which bacteria is causing the infection
3: Identify the antibiotics likely to be effective against this bacterium
4: Which of these antibiotics have the right characteristics e.g. oral

Question 3

Amoxicillin

Answer 3

Penicillin-based
Beta-lactam antibiotic
Oral route
Used for community acquired pneumonia caused by S. pneumoniae and H. influenzae
Used for cellulitis caused by Streptococcus pyogenes A

Question 4

Co-amoxiclav

Answer 4

Amoxicillin-clavulanic acid
Penicillin based
Oral route
Beta-lactam antibiotic (amoxicillin) plus clavulanic acid which prevents breakdown of the amoxicillin
Used for community acquired pneumonia caused by S. pneumoniae, Moraxellas cattharalis and H. influenzae
Used for cellulitis caused by Streptococcus pyogenes A and S. aureus

Question 5

Piperacillin-tazobactam

Answer 5

Penicillin based
IV route
Beta-lactam antibiotic and ureidopenicillin
Used for community-acquired pneumonia caused by S. pneumoniae, Moraxellas cattharalis, H. influenzae and Pseudomonas aeruginosa

Question 6

Aztreonam

Answer 6

IV and IM route
Monocyclic beta-lactam antibiotic
Used for community acquired pneumonia caused by Moraxellas cattharalis and H. influenzae

Question 7

Cefuroxime

Answer 7

Cephalosporin (beta-lactam)
IV, IM and oral route
Used for community acquired pneumonia caused by S. pneumoniae, Moraxellas cattharalis and H. influenzae
Used for cellulitis caused by S. aureus and Streptococcus pyogenes A
Also used for Lyme disease

Question 8

Erythromycin/ Clarithromycin/ Azithromycin

Answer 8

Macrolide antibiotics (protein synthesis antibiotics)
Often alternative for those with penicillin allergy
Oral route
Used for community-acquired pneumonia caused by S. pneumoniae, Moraxellas cattharalis, Legionella pneumophilia, Mycoplasma pneumoniae and Chlamydia pneumoniae
Macrolides in general can be used for cellulitis caused by S. aureus and Staphylococcus pyogenes A

Question 9

Vancomycin/ Teicoplanin

Answer 9

Glycopeptide antibiotic
Vancomycin can be used for MRSA
IV route
Used for community-acquired pneumonia caused by S. pneumonia
Used for cellulitis caused by S. aureus and Streptococcus progenies A

Question 10

Ciprofloxacin

Answer 10

Fluoroquinolone antibiotic - inhibits DNA replication
Oral and IV route
Used for community-acquired pneumonia caused by Moraxellas cattharalis, H. influenzae, Legionella pneumophilia, Mycoplasma pneumoniae and Chlamydia pneumoniae
Used for UTIs caused by E.coli

Question 11

Levofloxacin

Answer 11

Fluoroquinolone antibiotic - inhibits DNA replication
Oral and IV route
Used for community-acquired pneumonia caused by S. pneumoniae Moraxellas cattharalis, H. influenzae, Legionella pneumophilia, Mycoplasma pneumoniae and Chlamydia pneumoniae
Used for UTIs caused by E.coli

Question 12

Doxycycline

Answer 12

Broad spectrum tetracycline antibiotic
Oral and IV routes
Used for community-acquired pneumonia caused by S. pneumoniae, Moraxellas cattharalis, H. influenzae, Legionella pneumophilila, Mycoplasma pneumoniae and Chlamydia pneumoniae
Used for cellulitis caused by S. aureus and Streptococcus pyogenes A

Question 13

Meropenem/ Ertapenem

Answer 13

Broad spectrum carbapanem antibiotic
IV route
Used for UTI caused by E.coli
Carbapanems in general can be used for cellulitis caused by S. aureus and Streptococcus pyogenes A

Question 14

Gentamicin

Answer 14

Aminoglycoside antibiotic
IV route
Used for UTI caused by E. coli

Question 15

Nitrofurantoin

Answer 15

Oral route
Used for UTI caused by E.coli
Cannot treat anything other than mild cystitis

Question 16

Trimethoprim/ Co-trimoxazole

Answer 16

Dihydrofolate reductase inhibitor
Inhibits DNA synthesis
Oral route
Used for UTI caused by E. coli

Question 17

Fosfomycin

Answer 17

Inhibits bacterial cell wall genesis
Oral route
Used for UTI caused by E. coli

Question 18

Benzylpenicillin

Answer 18

Penicillin based antibiotic
Beta-lactam inhibitor
Also known as penicillin G
Used to treat cellulitis caused by Streptococcus pyogenes A

Question 19

Flucloxacillin

Answer 19

Penicillin based antibiotic
Beta-lactam inhibitor
Narrow-spectrum antibiotc
Used to treat cellulitis caused by S. aureus and Streptococcus pyogenes A