Chemotherapeutic Drugs

Question 1

Greatest activity to

Gram-Positive Organism
Gram-Negative Cocci
Non-B-lactamase producing anaerobes

Answer 1

PENICILLINS

Question 2

MOA of Penicillin

Answer 2

INHIBIT BACTERIAL GROWTH BY INTERFERING WITH TRANSPEPTIDATION REACTION OF BACTERIAL CELL WALL SYNTHESIS.

Question 3

Resistance to penicillin is due to? (4)

Answer 3

1. INACTIVATION OF ANTIBIOTIC BY B-LACTAMASE
2. MODIFICATION OF TARGET PBPs
3. IMPAIRED PENETRATION OF DRUG TO TARGET PBPs
4. EFFLUX

Question 4

Basis of methicillin resistance in staphylococci and of penicillin resistance in pneumococci and enterococci

Answer 4

ALTERED TARGET PBPs

Question 5

True or False.

Penicillins can be taken without food.

Answer 5

TRUE.

**absorption of most oral penicillins is impaired by food and drug should be administered at least 1-2 hours before or after meals.
(except amoxicillin)

Question 6

Nafcillin is cleared primarily by?

Answer 6

BILIARY EXCRETION

Question 7

Patient with renal failure was given high dose of penicillin, this can cause what?

Answer 7

SEIZURE

Question 8

A patient developed pseudomembranous colitis, what antibiotic could cause this?

Answer 8

AMPICILLIN

Question 9

What generation of cephalosporins is very active against Gram-positive Cocci?

Answer 9

FIRST GEN.

**cefazolin, cephalexin

Question 10

Drug of choice for surgical prophylaxis because it penetrates well into most tissues.

Answer 10

CEFAZOLIN

Question 11

Generation of cephalosporin with activity on ANAEROBES, and extended GRAM-NEGATIVE COVERAGE.

Answer 11

SECOND GENERATION.

**cefaclor, cefuroxime, cefoxitin

Question 12

Generation of cephalosporin with expanded gram-negative coverage, and able to cross the BBB.
Also effective in against haemophilus and neisseria.

Answer 12

THIRD GENERATION

**ceftriaxone, ceftazidime, cefixime

Question 13

Two drugs with useful activity against P.aeruginosa. They belong to what generation?

Answer 13

CEFTAZIDIME and CEFOPERAZONE

THIRD GEN.

Question 14

Given to:

GRAM-NEGATIVE RODS
P. AERUGINOSA
GRAM-POSITIVE ORGANISM
ANAEROBES

Answer 14

IMIPENEM

Question 15

This is an antibiotic produced by streptococcus orientalis and Amycolatopsis Orientalis.

This is only active against gram-positive bacteria (particularly staphylococci).

Answer 15

VANCOMYCIN

Question 16

Main indication of parenteral vancomycin

Answer 16

SEPSIS

ENDOCARDITIS caused by MRS

Question 17

Red man or Red neck syndrome is associated with what drug?

This is caused by what?

Answer 17

VANCOMYCIN

This is infusion-related flushing is caused by release of histamine.

Question 18

This drug inhibits a very early stage of bacterial cell wall synthesis. This is active against both gram-positive and gram-negative organisms at >125mcg/ml.

Answer 18

FOSFOMYCIN

**approved for use as single 3-g dose for tx of uncomplicated lower UTI in women. Safe for pregnancy.

Question 19

This drug when administered systemically is highly nephrotoxic and is only used topically.

Answer 19

BACITRACIN

**indicated for the suppression of mixed bacterial flora in surface lesion of the skin, wound, and mucous membranes

Question 20

Used almost exclusively to treat tuberculosis caused by strains of Mycobacterium tuberculosis resistant to first-line agents.

Answer 20

CYCLOSERINE