Synthetic Antibacterial Agents

Question 1

Patterned after nalidixic acid

Answer 1

Quinolones

Question 2

MOA of Quinolones

Answer 2

Mechanism of action- inhibits DNA synthesis by
inhibiting DNA gyrase (Topoisomerase II),

Question 3

DNA gyrase is also known as?

Answer 3

Topoisomerase II

Question 4

Enzyme responsible for unwinding & supercoiling of
bacterial DNA w/in bacterium before its replication.

Answer 4

DNA gyrase (Topoisomerase II)

Question 5

TRUE OR FALSE
Coincidental oral administration of a quinolone with an
antacid, a hematinic, or a mineral supplement can significantly reduce the oral bioavailability of the
quinolone.

Answer 5

TRUE

Question 6

TRUE OR FALSE
Substitution at C1 position decreases the activity remarkably or
changes the antibacterial characters

Answer 6

FALSE, its C2 position

Question 7

TRUE OR FALSE
Substitution at C5 , C6 , C7 and especially at C8 has good effects
on the activity of a quinolones.

Answer 7

TRUE

Question 8

At what position of Lomefloxacin =highest incidence of phototoxicity whereas those having an amino

Answer 8

Halogen at 8-position

Question 9

TRUE OR FALSE
7-hydroxymethyl metabolite = more active than parent compound (nalidixic acid)

Answer 9

TRUE

Question 10

Generic name of Ciprofloxacin?

Answer 10

Ciprobay

Question 11

Approved for the treatment of uncomplicated gonococcal urethritis & chancroid caused by
Haemophilus ducreyi (Single 400-mg dose)

Answer 11

Enoxacin (Abenox®)

Question 12

Agent of choice for bacterial gastroenteritis caused by Gram-negative
bacilli such as enteropathogenic E. coli, Salmonella spp. (including

Answer 12

Ciprofloxacin (Ciprobay®)

Question 13

A member of the quinolone class wherein the 1- and 8-positions are joined in the form of a 1,4-oxazine ring.

Answer 13

Ofloxacin (Inoflox®)

Question 14

Difluorinated quinolone w/ longer elimination half-life (7-8 hours) than
the others because of its excellent tissue distribution & renal
reabsorption

Answer 14

Lomefloxacin (Maxaquin®)

Question 15

Newer fluoroquinolone. Long elimination half-life: 18 hours ; given once-daily. More active against Chlamydia & anaerobe
Bacteroides fragilis

Answer 15

Sparfloxacin (Zagam®)

Question 16

First nitroheterocyclic compounds to be introduced
into chemotherapy

Answer 16

Nitrofurans

Question 17

Derivatives of 5-nitro-2-furaldehyde

Answer 17

Nitrofurans

Question 18

Antimicrobial activity is present only at what position for nitrofurans?

Answer 18

5-position

Question 19

Used topically for the treatment of burns

Answer 19

Nitrofurazone (Furacin®)

Question 20

Nitrofurans that is use for the treatment of urinary tract infections caused by susceptible strains of E. coli, enterococci, etc

Answer 20

Nitrofurantoin (Macrodantin®)

Question 21

It is recommended for the oral treatment of bacterial or protozoal diarrhea caused by susceptible
organisms. The usual adult dosage is 100 mg 4 times daily.

Answer 21

Furazolidone (Furoxone®)

Question 22

Hexamethylenetetramine (Urotropin)

Answer 22

Methenamine

Question 23

Methenamine is prepared by?

Answer 23

The compound is prepared by evaporating a solution of formaldehyde and strong ammonia water to
dryness.

Question 24

Local analgesic effect on the mucosa of the urinary tract.

Answer 24

Phenazopyridine Hydrochloride (Pyridium®)

Question 25

Activity depends on liberation of formaldehyde

Answer 25

Methenamine

Question 26

DOC for uncomplicated UTI

Answer 26

Cotrimoxazole

Question 27

DOC for PCP (Cotrimoxazole)

Answer 27

Cotrimoxazole

Question 28

Prevent and treat bacterial infection in burns

Answer 28

Ag Sulfadiazine
Mafenide

Question 29

Treatment of chloroquine-resistant malaria

Answer 29

Pyrimethamine + Sulfadoxine
(Fansidar ®).

Question 30

Large group of compounds that are structural analogs of
PABA

Answer 30

Sulfonamides

Question 31

First synthesized by Bayer Chemists, Josef Klarer and Fritz Mietzsch.

Answer 31

Prontosil

Question 32

First commercially available antibacterial drug.

Answer 32

Prontosil

Question 33

TTRUE OR FALSE
Prontosil is converted to sulfanilamide

Answer 33

TRUE

Question 34

MOA of Trimethoprim

Answer 34

Inhibits → dihydrofolate reductase (an enzyme
that catalyzes the reduction of dihydrofolic acid to
tetrahydrofolic acid of folate).

Question 35

DOC for severe traveler’s diarrhea

Answer 35

Cotrimoxazole or SULFAMETHOXAZOLE - TRIMETHOPRIM

Question 36

DOC for Toxoplasmosis

Answer 36

PYRIMETHAMINE-SULFADIAZINE

Question 37

Treatment of chloroquine-resistant malaria caused by Plasmodium
falciparum

Answer 37

PYRIMETHAMINE-SULFADOXINE

Question 38

Brand name for PYRIMETHAMINE-SULFADOXINE

Answer 38

Fansidar

Question 39

A/E of Sulfonamides?

Answer 39

1. Crystalluria → bleeding & kidney obstruction.
2. Hemolytic anemia → G6PD patients
3. Rashes → Hypersensitivity reaction.
4. Agranulocytosis
5. N/V
6. Kernicterus →Toxic encephalopathy (brain damage caused by
   excessive bilirubin).
7. Stevens-Johnson Syndrome (SJS)

Question 40

Give the first generation of Quinolones

Answer 40

Nalidixic acid and Cinoxacin

Question 41

Give the 3rd generation of Quinolones

Answer 41

Levofloxacin, Gatifloxacin, Sparfloxacin

Question 42

Give the 4th generation of Quinolones

Answer 42

Moxifloxacin and Trovafloxacin

Question 43

Give the 2nd generation of Quinolones

Answer 43

Norfloxacin, Ofloxacin, Ciprofloxacin, Lomefloxacin, Enfloxaciin

Question 44

Can inhibit aldehyde dehydrogenase (dilsulfiram like-effect)

Answer 44

Furazolidone