Antibiotics

Question 1

Cell wall with lots of peptidoglycan?

Answer 1

Gram positive cell wall

Question 2

Antibiotics that act on the bacterial cell wall?

Answer 2

Penicillins
Cephalosporins
Glycopeptides

Question 3

How are penicillins excreted?

Answer 3

Via the kidneys

Question 4

Are penicillins safe in pregnancy?

Answer 4

Yes

Question 5

Vancomycin and Teicoplanin, what type of antibiotic are these?

Answer 5

Glycopeptides (they act on the bacterial cell wall)

Question 6

How do you give glycopeptides?

Answer 6

Give glycopeptides IV as they are not absorbed when given orally

Question 7

What is clavulanic acid?

Answer 7

Calvulanic acid is a beta-lactamase inhibitor

Question 8

What is tazobactam?

Answer 8

Beta-lactamase inhibitor

Question 9

Name some macrolides

Answer 9

Erythromycin, clarithromycin and azithromycin

Question 10

How are macrolides excreted?

Answer 10

Excreted via the liver, biliary tract and into the gut (NOT EXCRETED IN URINE)

Question 11

How is gentamicin administered?

Answer 11

IV

Question 12

What does gentamicin cover?

Answer 12

Gentamicin is active mainly against Gram negative aerobic organisms such as coliforms and Pseudomonas aeruginosa

Question 13

Really bad side effects of gentamicin?

Answer 13

Gentamicin has a narrow therapeutic index

CAUSES RENAL FAILURE AND DEAFNESS AND DISTURBANCE OF BALANCE

Question 14

What are tetracyclines good for?

Answer 14

Atypical penumonia organisms

Treating infections caused by bacteria that do not have a proper bacterial cell wall

Question 15

How are clindamycin, chloramphenicol and tetracyclines excreted?

Answer 15

Via the liver and biliary system

Question 16

Antibiotics that act on bacterial DNA

Answer 16

Metronidazole
Trimethoprim
Fluoroquinolones (ciprofloxacin, levofloxacin)

Question 17

Uses of metronidazole

Answer 17

Metronidazole is used for infection caused by “true anaerobes”

• Bacteroides
• Clostridium

Question 18

How does trimethroprim work?

Answer 18

Inhibits folic acid synthesis

-Has some activity against gram negative and gram positive

Question 19

How is trimethoprim excreted?

Answer 19

Excreted in urine

Question 20

When is trimethoprim safe in pregnancy?

Answer 20

Safe in pregnancy from 4th month onward

Question 21

Which are the only antibiotics that can be given orally to treat pseudomonas infection?

Answer 21

Fluoroquinolones (ciprofloxacin, levofloxacin)

-Use of these antibiotics is restricted though

Question 22

Uses of ciprofloxacin and levofloxacin?

Answer 22

Ciprofloxacin is used for complicated urinary tract infection

Levofloxacin is used ONLY for severe community acquired pneumonia in penicillin allergic patients

Question 23

General antibiotic side effects

Answer 23

Many cause GI effects such as nausea and diarrhoea. This may result in failure of oral contraception and another method of contraception is usually required

Question 24

Side effect of glycopeptides? (vancomycin)

Answer 24

vancomycin damages kidneys, occasionally causes “red man syndrome” (allergy)

Question 25

Side effect of tetracyclines?

Answer 25

permanent staining of teeth (and bones) in children <12 years

Question 26

Side effect of metronidazole?

Answer 26

Interacts with alcohol

Question 27

Side effects of quinolones?

Answer 27

weakens tendon (→ tendon rupture)
May damage joints in children
May cause seizures (“fits”)

Question 28

Antibiotics that should be avoided in people with penicillin allergy?

Answer 28

Patients with penicillin allergy should not be given penicillins/cephalosporins

Question 29

When is metronidazole safe in pregnancy?

Answer 29

Metronidazole is safe after the first 3 months (like trimethoprim)

Question 30

Which antibiotics should you not give to pregnant women?

Answer 30

You should not give:

• gentamicin
• tetracyclines
• fluoroquinolones