1

Question 1

Gentamicin

Answer 1

diminished renal clearance in pts with renal failure

Question 2

Erythromycin

Answer 2

stimulates gut motilin receptors and may induce nausea

Question 3

Components of interaction

Answer 3

Pharmacokinetics 
Pharmacodynamic 
Immunity 
Resistance 
Sepsis 
Selective toxicity

Question 4

General taxonomy depending on mechanism of action

Answer 4

ribosomal inhibitors (macrolides),
Cell wall disrupters (B-lactams),
 DNA disturbers (fluoroquinolones),
 metabolic poisons (trimethoprim-sulfamethoxazole)

Question 5

Antibiotics also classified based on laboratory
assessment of the interaction of pathogen and
antibiotic drug

Answer 5

Static

Cidal

Question 6

Arsenic

Answer 6

1800s for syphilis

Question 7

Sulfonamides

Answer 7

1935 synthetic antimicrobial agents

Question 8

Sulphonamides

Answer 8

Nh2 is essential
Benzene ring attached to sulfur
Causes nausea rashes dyscrasia precipitation and stones
Structural analogs and competitive competitive antagonist for PABA

Question 9

Cotrimoxazole- Trimethoprim
Combination (Bactrim, Septrin,
Balakatrin):

Answer 9

One of the few, still used, sulfa drugs.
– Very effective fixed combination.
– No resistance.
– Very useful in UTI, RTI, Salmonella, 
and Pneumocystis pneumonia, an 
opportunistic infection in AIDS 
patients.

Question 10

Quinolones

Answer 10

Interfere with cell division of bacteria.

Question 11

Nalidixic acid

Answer 11

Very old urinary antiseptic

Question 12

Norfloxacin

Answer 12

UTI

3 day course

Question 13

fluorinated 4-quinolones

Answer 13

Ciprofloxacin
moxifloxacin
(AVELOX), and gatifloxacin (TEQUIN)

Question 14

Ciprofloxacin

Answer 14

Prophylactic for meningitis
Wide range of activity botulinum
Cause gi upset and epilepsy

Question 15

Quinolones

Answer 15

Carboxylic acid group at position 3 
Chromophore group 
 target bacterial DNA gyrase and 
Topoisomeras which is responsible for the continuous introduction of 
negative supercoils into DNA
inhibit the nicking and 
closing activity of the gyrase and also 
block the activity of topoisomerase IV

Question 16

Nitrofurans

Answer 16

A number of 5-nitro-2-furaldehyde derivatives
treatment and/or prophylaxis
of microbial infections, primarily in the urinary
tract
• modify various bacterial macromolecules that
affect a variety of biochemical processes (e.g.,
DNA and RNA synthesis, protein synthesis )
the slower reduction by
mammalian cells prevents high serum concentrations.
gramnegative bacteria (E. coli, P. mirabilis is variable) and
some susceptible gram-positive organisms, such as
S. aureus and Enterococcus faecalis

Question 17

Nitrofurans

Answer 17

The singular indication for nitrofurantoin is the treatment and longterm prophylaxis of lower UTIs caused by susceptible bacteria
• it is not used as a bacterial suppressant.
• It is often used prophylactically post intercourse in women with
chronic UTIs
greater than 100 ug/mL ensures bactericidal activity
Nausea and vomiting

Question 18

Methenamine

Answer 18

have two major effects :
bactericidal ( formaldehyde) / bacteriostatic ( lowering urine pH )
mandelic (Mandelamine) or
hippuric (Hiprex, Urex) acid.
administered orally and is well absorbed from
the intestinal tract.
10 to 30% decomposes in the stomach unless the tablets are
protected by an enteric coating
inactive form (methenamine) is distributed to virtually
every bodyfluid
Prophylaxis of uti
Sterilise urine

Question 19

Beta lactam antibiotics

Answer 19

Contain b lac ring
Inhibit cell wall synthesis
•Oldest antibiotics, but still growing and
new agents are still discovered and added
to the group.
Penicillin g
Lactamase

Question 20

Penicillins

Answer 20

Are the most widely used antibiotics.
◼ Penicillin G was found very effective against the
most common and important Gram positive
bacteria like Staph, Strept, Pneumococcus, and
many others.

Question 21

Penicillinase

Answer 21

Inactivates penicillin by breaking the beta lactam ring

Clavulanic acid combined with ampicillin inhibits it = augmentin /amoclan

Question 22

Penicillin actions

Answer 22

The cell walls of bacteria are essential 
for their normal growth and 
development
•Peptidoglycan provides rigid mechanical 
stability
gram-positive 
microorganisms, the 
cell wall is 50 to 100 
molecules thick,
• but it is only 1 or 2 
molecules thick in 
gram-negative bacteria
last step in peptidoglycan synthesis that is inhibited by the β-lactam 
antibiotics

Question 23

B lactamase inhibitors

Answer 23

Clavulanic acid
Sublactam
Tazobacta

Question 24

Penicillin g

Answer 24

Benzyl penicillin 
Deep IM injection 
Highly active against sensitive strains of gram + cocci 
Hydrolyzed by penicillinase
Ineffective s aureus

Question 25

Procain benzyl penicillin

Answer 25

Painless, prolonged

action injection

Question 26

Phenoxymethyl penicillin

Answer 26

Oral not destroyed by gastric acid