Antibiotics

Question 1

Classes of antimicrobials [8]

Answer 1

Penicillins
Carbapenems
Cephalosporins
Tetracyclines
Macrolides
Gram-negative cover
Gram positive cover
Miscellaneous

Question 2

Bacterial classification: gram positives 5 subgroups

Answer 2

• Strep: streptococcus pneumoniae, group A, B, C, G
• Staph: aureus
• MRSA: MRSA, coagulase -ve staph
• Enterococci: enterococcus faecalis, enterococcus faecum
• Gram +ve anaerobes: anaerobic strep, clostridium

Question 3

Bacterial classification: gram negatives 5 subgroups

Answer 3

• Gram -ve anaerobes: bacteroides fragilis
• Coliforms: gut bacteria e.g. E. coli
• Respiratory: haemophilus influenza, Moraxella catarrhalis
• Pseudomonas
• ESBL: extended spectrum beta lactamase producers and other resistant gram -ves

Question 4

What are 3 examples of atypical organisms

Answer 4

Legionella
chlamydia
mycoplasma

Question 5

2 mechanism of actions that antibiotics take [4]

Answer 5

Bactericidal e.g. inhibit cell wall, protein, nucleic acid synthesis
Bacteriostatic e.g. inhibit folic acid synthesis

Question 6

Penicillin
MOA
Eg [5]

Answer 6

MOA: Bactericidal, inhibit cell wall synthesis
Examples:
- Benzylpenicillin, Penicillin V
- Flucloxacillin
- Amoxicillin
- Co-amoxiclav
- Tazocin

Question 7

Carbapenems
MOA
Eg [1] - what are these sensitive to? [9]

Answer 7

MOA: Bactericidal, inhibit cell wall synthesis

MEROPENEM:
staph, strep, enterococci, gram +ve and gram -ve anaerobes, coliforms, respiratory, pseudomonas, ESBL

Question 8

Cephalosporins
MOA
Name all 3 generation

Answer 8

MOA: Bactericidal, inhibit cell wall synthesis
• 1st generation (CEFALEXIN)
• 2nd generation (CEFUROXIME)
• 3rd generation (CEFRIAXONE and CEFOTAXIME)

Question 9

What is the association between cephalosporins and penicillins

What is the difference in MOA between generations?

Answer 9

• Penicillin allergy is present, 10% chance of having similar reaction to cephalosporins

As we go down the generations, the more action on gram positive organisms and vice versa for gram negative

Question 10

Tetracyclines
MOA
Eg of tetraycline
Sensitivities [4]

Answer 10

MOA: bacteriostatic; inhibit protein synthesis
Eg: doxycycline
MRSA, staph, respiratory, atypicals

(some strep, gram +ve anaerobes, coliforms and ESBL)

Question 11

Antifolate antibiotics
MOA
Eg [2]

Answer 11

MOA: bacteriostatic; inhibit folic acid synthesis
Eg: Trimethoprim and cotrimoxazole

Question 12

Macrolides
MOA
Eg [2]

Answer 12

MOA: inhibit protein synthesis
Eg: Azithromycin, clarithromycin

Question 13

Clindamycin
MOA
Sensitivities [4]

Answer 13

MOA: bacteriostatic

Strep, staph, gram +ve and -ve anaerobes

Question 14

Gram negative cover - 2 classes of antibiotics, what are their respective MOAs and give 2 examples each

Answer 14

Fluoroquinolones - bactericidal; inhibit nucleic acid synthesis
Eg: ciprofloxacin, levofloxacin

Aminoglycosides - bactericidal; inhibit protein synthesis
Eg: gentamicin and tobramycin

Question 15

Gram negative cover - Fluoroquinolones. What are the sensitivities of:
Ciprofloxacin [4]
Levofloxacin [5]

Answer 15

CIPROFLOXACIN: coliforms, respiratory, pseudomonas, atypicals (some staph, strep, enterococci and ESBL)

LEVOFLOXACIN: staph, strep, coliforms, respiratory, pseudomonas (some enterococci and ESBL)

Question 16

What is another gram negative antibiotic apart from fluoroquinolone and aminoglycosides?
Sensitivities [4]

Answer 16

• FOSFOMYCIN:

MRSA, staph, coliforms, ESBL (some strep)

Question 17

What are 2 side effects of gentamicin and tobramycin?

Answer 17

Nephro and ototoxic

Question 18

Gram positive cover
MOA
Eg
SE
Sensitivities

Answer 18

MOA: bactericidal; Inhibit cell wall synthesis

VANCOMYCIN and TEICOPLANIN

SE: nephrotoxic

MRSA, staph, strep, enterococci, gram +ve anaerobes, c. diff

Question 19

Sensitivities of the penicillin family:
Benzylpenicillin and penicillin V [2]
Flucloxacillin [2]
Amoxicillin [2]

Answer 19

• BENZYLPENICILLIN and PENICILLIN V: strep, enterococci (some gram +ve and -ve anaerobes)
• FLUCLOXACILLIN: staph, strep
• AMOXICILLIN: strep, enterococci (some gram +ve and -ve anaerobes, gram -ve coliforms, respiratory gram -ves)

Question 20

Sensitivities of the penicillin family:
Co-amoxiclav [5]
Tazocin [8]

Answer 20

• CO-AMOXICLAV:
staph, strep, enterococci, gram +ve and -ve anaerobes, coliforms, respiratory

• TAZOCIN:
staph, strep, enterococci, gram +ve and gram -ve anaerobes, coliforms, respiratory, pseudomonas

Question 21

What is tazocin a combination of?

Answer 21

TAZOBACTAM and PIPERACILLIN

Question 22

Sensitivities of the cephalosporin family:
1st gen cefalexin [3]
2nd gen cefuroxime [4]
3rd gen cefriaxone and cefotaxime [4]

Answer 22

• 1st generation (CEFALEXIN): staph, strep, coliforms
• 2nd generation (CEFUROXIME): staph, strep, coliforms, respiratory
• 3rd generation (CEFRIAXONE and CEFOTAXIME): staph, strep, coliforms, respiratory

Question 23

Sensitivities of the anti-folate antibiotics:
Trimethoprim [1]
Co-trimoxazole [3]

Answer 23

• TRIMETHOPRIM: coliforms

* CO-TRIMOXAZOLE (TRIMETHOPRIM + SULPHAMETHOXAZOLE): staph, strep, coliforms

Question 24

What is a Co-trimoxazole combination of?

Answer 24

TRIMETHOPRIM + SULPHAMETHOXAZOLE

Question 25

Sensitivities of the Macrolides antibiotics:
Erythromycin [1]
Azithromycin and clarithromycin [3]

Answer 25

• ERYTHROMYCIN: atypicals

* AZITHROMYCIN and CLAIRITHORMYCIN: staph, respiratory, atypicals

Question 26

Sensitivities:
Metronidazole [3], SE
Nitrofurantoin [1]
Rifampicin [5]

Answer 26

• METRONIDAZOLE: gram +ve and -ve anaerobes, protozoal, alcohol SE
• NITROFURANTOIN: coliforms in LUTI
• RIFAMPICIN: MRSA, staph, strep, respiratory, atypicals

Question 27

Sensitivities: Chloramphenicol [7]

Answer 27

CHLORAMPHENICOL:

MRSA, staph, strep, gram +ve and -ve anaerobes, coliforms, respiratory