Clinical use of Antibiotics 3

Question 1

Give four micro-organisms that cause urethritis

Answer 1

Neisseria gonorrhoea, Chlamydia trachomatis, Ureaplasma urealyticum & Mycoplasma genitalium

Question 2

Why is empirical treatment of urethritis often necessary?

Answer 2

Therapy is often started on the presence of gram negative cocci, which can include both N.gonorrhoea and C.trachomatis. Empirical treatment can cover both of these without further testing

Question 3

What is empirical treatment?

Answer 3

Clinical therapy started on the basis of a well educated guess, in the absence of complete or perfect information

Question 4

Why would you use culture to detect N.gonorrhoea instead of PCR?

Answer 4

Culture can give sensitivities of the strain, which is useful for determining treatment

Question 5

What are some of the drugs N.gonorrhoea is exhibiting resistance to?

Answer 5

Amoxycillin & Penicillin
1st and 2nd generation cephalosporins
Tetracyclines
Quinolones

Question 6

What are the antibiotics used to treat N.gonorrhoea in rural/remotes areas?

Answer 6

Amoxycillin & probenicid

Question 7

What are the antibiotics used to treat N.gonorrhoea in metropolitan areas?

Answer 7

Empirical choice is a single dose of IMI ceftriaxone

Question 8

What is the antibiotic used to treat Chlamydia?

Answer 8

A single dose of azithromycin (1gm)

Question 9

What is the empirical treatment for Urethritis, without lab results?

Answer 9

Single dose of both azithromycin and IMI ceftriaxone, to cover both Chlamydia and gonorrhoea

Question 10

How is atypical pneumonia different from normal pneumonia?

Answer 10

A patient will have both an upper and lower respiratory tract infection i.e. presents with both a cough and pharyngitis

Question 11

What are some of the main causes of atypical pneumonia?

Answer 11

Mycoplasma pneumoniae, Chlamydophilia pneumoniae, legionella longbeachae, Legionella pneumophilia, Chlamydophilia psittaci. Haemophilus influenzae may also be a cause

Question 12

What is empirical treatment of atypical pneumonia?

Answer 12

Doxycycline (tetracycline), clarithromycin or azithromycin, both of which are macrolides

Tetracyclines cover Chlamydophilia, Mycoplasma and Legionella species, while Macrolides cover Haemophillus, Chlamydophilia, Legionella pneumophilia and Mycoplasma species

Question 13

What is a polymicrobial infection?

Answer 13

An infection caused by several species of micro-organisms

Question 14

Why are diabetic foot ulcers polymicrobial?

Answer 14

The bare foot is exposed to a range of organisms, and in a immunocompromised host with an open wound, the resulting infection is usually caused by a number of tehse organisms

Question 15

What are some of the species you would find in a diabetic foot ulcer?

Answer 15

Enterobacteriaceae
Pseudomonas aeruginosa 
Staph aureus 
Alpha- and beta-haemolytic Streptococcus species
Bacteroides

Question 16

Which antibiotics are useful against anaerobic bacteria in early infection of DFU?

Answer 16

In early infection:

• Augmentin (amoxycillin + clavulanic acid)
• Clindamycin po (a lincosamide)
• Metronidazole, which is only active against anaerobes

Question 17

What must you always consider with deep foot ulcers?

Answer 17

Underlying Osteomyelitis

Question 18

Which antibiotics are useful against anaerobic bacteria in deep or bone infection in DFU?

Answer 18

• Timentin IV (ticarcillin + clavulanic acid) + Tazocin IV (piperacillin + tazobactam)
• Meropenem IV (a carbapenem)

Question 19

What is a typical antibiotic regimen for early diabetic foot infection?

Answer 19

You would give:
Augmentin to cover gram positive species, enterobacteriaceae and anaerobes,
Cephalexin to cover gram positive and some enterobacteriaceae, and metronidazole to cover anaerobes