spectrum of commonly used agents

Question 1

Benzyl penicillin

Answer 1

beta lactam
penicillin
gram positive organisms
plus menigococci gram negative exception
Most used for IV treatment against serious pneumonococcal, meningococcal and Strep pyogenes group A infection

Question 2

beta lactam
penicillin
Much better oral absorption than benzyl penicillin
gram negative organisms
20-30% coliforms resistant
also streptococci

Answer 2

Amoxicillin/ ampicillin

Question 3

Co-amoxiclav

Answer 3

beta lactam
penicillin
amoxicillin + beta lactamase inhibitor clauvulnic acid

Question 4

beta lactam
penicillin
Resistant to beta lactamase from staphylococcal

Answer 4

Flucloxacillin

Question 5

Piperacillin

Answer 5

beta lactam
broad spectrum penicillin
active against pseudomonas
anti-anaerobic activity so used for serious intra-abdominal infection

Question 6

beta lactam
carbapenem
widest spectrum of all
active against most bacteria including anaerobes

Answer 6

Imipenem, meropenem

Question 7

Why has the use of cephalosporins decreased markedly in recent years?

Answer 7

They encourage Clostridium difficile infection

Question 8

Does the effect of cephalosporins on gram negative bacteria increase or decrease as you go up the generations?
And gram positive?

Answer 8

Increases - gram negative

Decreases - gram positive

Question 9

Gentamicin

Answer 9

aminoglycoside
gram negative organisms inc. pseudomonas
also Staphylococci

Question 10

glycopeptides (name two types)
gram positive organisms
aerobic and anaerobic
one very toxic

Answer 10

Vancomycin and teicoplanin

Question 11

Clarithromycin or Erythromycin

Answer 11

macrolides
gram positive organisms
alternate to penicillin for those with penicillin hypersensitivity
affective against organisms causing ‘atypical pneumonia’

Question 12

macrolide

single doses treatment of Chlamydia infection

Answer 12

Azithromycin

Question 13

When would quinolones be used?

Answer 13

If previous treatment didn’t work as high toxicity

Question 14

Metronidazole

Answer 14

miscellaneous

anaerobes - gram negative and gram positive

Question 15

miscellaneous
anti-staphylococcul drug
diffuses well into bone and tissues
staph aureus very resistant so used in combination

Answer 15

Fusidic acid

Question 16

Trimethroprim

Answer 16

miscellaneous
treatment of UTIs
when combined with sulfamethoxazole it is co-trimoxazole

Question 17

miscellaneous
broad spectrum agents
inhibit bacterial protein synthesis
few applications
not suitable for pregnant woman or children under 12

Answer 17

Tetracyclines

Question 18

Clindamycin

Answer 18

miscellaneous
gram positive organisms - staph and strep, anaerobes
very good tissue penetration
common cause of pseudo-membranous colitis

Question 19

Linezolid

Answer 19

miscellaneous
activity against MRSA
can be given orally
can cause bone marrow suppression

Question 20

Daptomycin

Answer 20

miscellaneous
gram positive organisms
treatment against serious MRSA

Question 21

Fidaxomicin

Answer 21

miscellaneous
bactericidal against C. difficile
narrower spectrum than metronidazole and vancomycin

Question 22

Which two agents are used only in the treatment of urinary tract infections?

Answer 22

Nalidixic acid and Nitrofurantoin