Antibiotics

Question 1

How do penicillins work?

Answer 1

Inhibiting cell wall synthesis by preventing the cross linking of peptidoglycan subunits.

Question 2

Are penicillins bacteriostatic or bacteriocidal?

Answer 2

Bacteriocicdal

Question 3

How are penicillins excreted?

Answer 3

Via the kidneys

Question 4

Atre penicillins safe in pregnancy?

Answer 4

Yes

Question 5

Name three groups of antibiotics that act on the bacterial cell wall

Answer 5

Penicillins
Cephlasporins
Glycopeptides

Question 6

Give an example of a glycopeptide antibiotic

Answer 6

Vancomycin

Question 7

Give an example of a cephlasporin antibiotic

Answer 7

Ceftriaxone

Question 8

What penicillin gives gram positive cover only?

Answer 8

Flucloxacillin

Question 9

What peniciliin given gram negative and gram positive cover?

Answer 9

Amoxicillin
Co amoxiclav
Pipercillin/Tazobactam

Question 10

What organisms are sensitive to flucloxacillin?

Answer 10

Gram positive staphylococci and streptococci

Question 11

What does the clavulanic acid do in co amoxiclav?

Answer 11

Inhibits the action of the beta lactamase enzyme produced by bacteria

Question 12

What is temociilin active against?

Answer 12

Coliforms

Question 13

How do glycopeptide antibiotics work?

Answer 13

Bind to the end of the growing peptide chain and prevent cross linking. This then weakens the bacterial cell wall.

Question 14

Are glycopeptides bacteriocidal or bacteriostatic?

Answer 14

bacteriocidal

Question 15

Do glycopeptides work on gram negative organisms, gram positive organisms or both?

Answer 15

ONLY gram positive

Question 16

Name the main groups of antibiotics that inhibit protein synthesis

Answer 16

Macrolides
Tetracyclines
Aminoglycosides
Clindamycin
Chloramphenicol

Question 17

Name three macrolide antibiotics

Answer 17

Erythromycin
Clarithromycin
Azithromycin

Question 18

Name an aminoglycoside antibiotic

Answer 18

Gentamicine

Question 19

Are antibiotics that inhibit protein synthesis bacteriostatic or bacteriocidal?

Answer 19

Bacteriostatic. They attach to bacterial ribosomes and stop further protein synthesis. However, protein synthesis can usually resume once the antibiotic is removed.

Question 20

How are macrolide antibiotics excreted?

Answer 20

Liver

Question 21

Are macrolides lipophillic or lipophobic?

Answer 21

Lipophillic; they pass through cell membranes easily. Useful for infections where bacteria hide from the host’s immune system.

Question 22

How is gentamicin administered and why?

Answer 22

Must be given IV or IM as it is not absorbed from the gut.

Question 23

What infections are treated with gentamicin?

Answer 23

It is active against gram negative aerobic organisms such as coliforms and pseudomonas aeruginosa. It is used in hospital for treating serious gram negativ infection.

Question 24

What are some of the risks of gentamicin.

Answer 24

Toxic to the kidneys

VIIIth cranial nerve damage (causes deafness and dizziness)

Question 25

What groups of antibiotics act on bacterial DNA?

Answer 25

Metronidazole Trimethoprim Fluroquinolones

Question 26

What kind of organisms is metronidazole active against?

Answer 26

True anaerobic

Question 27

What four antibiotics are associated with an increased risk of C diff?

Answer 27

Cephlasporins Co - amoxiclav Ciprofloxacin Clindamycin