Antibiotics

Question 1

4 causes of infection

Answer 1

Bacteria
Fungi
Viruses
Protozoa

Question 2

what are antibiotics

Answer 2

broadly kill pathogens without killing people
There is an overlap between antibiotics and antiseptics, but essentially antibiotics bind to specific targets while antiseptics act more generally.

Question 3

what are antimicrobials

Answer 3

echnically most meaningful, man-made whereas antibiotics are naturally created

Question 4

how do we use antibiotics (4)

Answer 4

Treatment of infection
	Curative- ‘course’ of varying length 
	Suppressive- often indefinitely
Prevention of infection 
	Before the infective agent 
		Prophylaxis- usually single dose
		E.g., operative prophylaxis
	After the infective agent 
		e.g., meningococcal contact “prophylaxis”, bite injuries
Empiric therapy
	“best guess”
	e.g., co-amoxiclav +/- gentamicin for suspected urosepsis
Targeted therapy
	Directed against a specific organism
	e.g., blood cultures growing E.coli susceptible to amoxicillin

Question 5

major groups of antibacterials

Answer 5

beta lactams
macrolides
tetracyclins
aminoglycosides
quinolones
glycopeptides
others

Question 6

examples of beta lactams

Answer 6

a. Penicillins (-illin)
b. Cephalosporins (-exin)
c. Monobactams (-nam)
d. Carbapenams (-enem)

Question 7

examples of marolides

Answer 7

erythromycin, clarithromycin,, alternatives to penicillins in many situations,

Question 8

examples of tetrocyclines

Answer 8

(doxycycline, PO treatment of respiratory infections, ok for skin infections, long term use e.g., acne, preganant and breast feeding women)

Question 9

examples of quinolones

Answer 9

(ciprofloxacin, stops cell growing/ dividing, usually used when no other side effects)

Question 10

examples of glycopeptides

Answer 10

(ciprofloxacin, stops cell growing/ dividing, usually used when no other side effects)

Question 11

“other” antibacterials

Answer 11

a. Trimethoprim (restricted to PO treatment or simple UTI)
b. Metronidazole (against strict anaerobes, often used in combination
c. Rifampicin (used as part of multi-drug TB regimes)

Question 12

TB meds

Answer 12

RIPE
rifampicin
isoniazid
pyrazinamide
ethambutal

Question 13

likely pathogens for cellulitis (2)

Answer 13

Probably streptococcus pyogenes

Possibly staphylococcus aureus

Question 14

typical treatment for cellulitis

Answer 14

Flucloxacillin mainly
Ceftriaxone
Clindamycin
Linezolid
Daptomycin
Etc

Question 15

Community acquired pneumonia Likely pathogens:

Answer 15

Streptococcus pneumoniae
Haemophilus influenzae
Could be legionella etc

Question 16

typical treatment for pneumonia

Answer 16

Co-amoxiclav + clarithromycin

Question 17

4 mechanisms of acquired resistance

Answer 17

1. Bacterium destroys the bacterium
2. Bacterium modifies its target
3. Bacterium reduces permeability
4. Bacterium pushes it out (efflux pumps)

Question 18

simple UTI symptoms

Answer 18

• Burning or painful urination
• Constant urge to urinate
• Cloudy urine
• Foul odour to urine

Question 19

management of simple UTI

Answer 19

Manage symptomatically 
Take a sample, wait and give a targeted treatment 
Treat empirically 
	Cover E.coli
	Choose something well absorbed PO
	Something well tolerated and preferably cheap 
Nitrofurantoin
Trimethoprim

Question 20

drugs for bronchitis

Answer 20

Doxycycline, amoxicillin, clarithromycin

Question 21

drugs for skin infection

Answer 21

Flucloxacillin
Doxycycline
Clarithromycin

Question 22

drugs for endocarditis

Answer 22

High dose amoxicillin plus gentamycin

Vancomycin plus gentamycin

Question 23

drugs for bacterial meningitis

Answer 23

Cefotaxamine =/- amoxicillin