PHARMACO - Chloramphenicol

Question 1

?S ribosomes in bacteria

Answer 1

70

Question 2

?S ribosomes in mammalians

Answer 2

80

Question 3

 Basis for selective toxicity against microorganisms without causing major effects on mammalian cells
3 Differences

Answer 3

 Ribosomal subunits
 Chemical composition
 Functional specificities of component nucleic acids and proteins

Question 4

General MoA

Answer 4

Bactericidal

Question 5

General binding at what ribosome

Answer 5

50S except for tetracycline

Question 6

 Inhibits transpeptidation (catalyzed by peptidyl transferase)

Answer 6

chloramphenicol

Question 7

 Blocks the binding of aminoacyl moiety of tRNA to mRNA complex so the peptide at the donor site cannot be transferred to the amino acid acceptor

Answer 7

chloramphenicol

Question 8

 Bind at 50S-block translocation of peptidyl-tRNA from the acceptor site to the donor site

Answer 8

 Macrolides, telithromycin, and clindamycin

Question 9

 Bind to 30S

Answer 9

 Tetracyclines

Question 10

 Blocks the binding of amino-acid-charged tRNA to the acceptor site

Answer 10

 Tetracyclines

Question 11

 Constrict the exit channel on the ribosome through which polypeptides are extruded tRNA synthase activity is inhibited

Answer 11

 Streptogramins

Question 12

inhibits tRNA synthase activity

Answer 12

 Streptogramins

Question 13

bactericidal AB which bind to the 50S

Answer 13

 Streptogramins

Question 14

 Bacteriostatic
 Binds to a unique site at 50S
 Blocks formation of tRNA-ribosome-mRNA complex

Answer 14

 Linezolid

Question 15

Broad spectrum

Answer 15

chloramphenicol

tetracycline

Question 16

moderate spectrum

Answer 16

macrolides

ketolides

Question 17

narrow spectrum

Answer 17

lincosamides
streptogramins
linezolid

Question 18

newer antibiotics

Answer 18

streptogramins

linezolid

Question 19

Are there other antimicrobial drugs in chloramphenicol class

Answer 19

No

Question 20

RoA of Chloramphenicol

Answer 20

 Oral as well as parenteral

Question 21

Tissue distribution of Chloramphenicol

Answer 21

Distributed throughout all tissues

Question 22

Crosses placental and blood-brain barriers

Answer 22

Chloramphenicol

Question 23

Undergoes enterohepatic cycling

Answer 23

Chloramphenicol

tetracycline

Question 24

Enzyme that inactivates chloramphenicol

Answer 24

hepatic glucoronosyltransferase

Question 25

Does Chloramphenicol undergo enterohepatic cycling

Answer 25

Yes

Question 26

Fraction excreted in urine unchanged or changed in chloramphenicol?

Answer 26

unchanged

Question 27

MoA of Chloramphenicol

Answer 27

 Bacteriostatic

Question 28

When does Chloramphenicol become bactericidal

Answer 28

 H. influenzae  N. meningitidis  Bacteroides

Question 29

Is chloramphenicol effective for chlamydia

Answer 29

No

Question 30

Resistance to chloramphenicol

Answer 30

 Plasmid mediated-formation of acetyl- transferases that inactivate the drug

Question 31

chloramphenicol is Rarely used as a systemic drug because

Answer 31

of its toxicity

Question 32

Backup drug for severe infections caused by salmonella

Answer 32

chloramphenicol

Question 33

 Treatment of pneumococcal and meningococcal meningitis in beta-lactam-sensitive persons

Answer 33

chloramphenicol

Question 34

 Commonly used as topical agent

Answer 34

chloramphenicol

Question 35

 Sometimes used for ricketssial infections |  Infections caused by anaerobes like B. fragilis

Answer 35

chloramphenicol

Question 36

GI disturbances occur from

Answer 36

direct irritation and superinfection which may lead to candidiasis

Question 37

toxicity of chloramphenicol in the bone marrow

Answer 37

 Inhibition of red cell maturation-decrease in circulating RBC  Dose dependent and reversible

Question 38

toxicity of chloramphenicol  Rare idiosyncratic reaction  Irreversible and maybe fatal

Answer 38

aplastic anemia

Question 39

toxicity of chloramphenicol  Premature infants  Deficiency of hepatic glucoronyltransferase  Tolerated in older infants  Decreased RBC, cyanosis and cardiovascular collapse

Answer 39

gray baby syndrom

Question 40

enzyme only present in mature liver

Answer 40

hepatic glucoronosyltransferase

Question 41

disease in which all formed elements decrease in level | caused by chloramphenicol

Answer 41

pancytopenia

Question 42

prototype drug of tetracycline

Answer 42

tetracycline

Question 43

drug that must be taken before meals as its absorption is impaired by food and multivalent cation

Answer 43

tetracycline

Question 44

tissue distribution of tetracyclines (narrow or wide)

Answer 44

wide

Question 45

crosses the placental barrier

Answer 45

tetracycline

Question 46

contraindicated in pregnancy because it crosses the placental barrier

Answer 46

tetracycline and chloramphenicol

Question 47

mode of elimination

Answer 47

urine except for ____

Question 48

 All tetracycline drugs eliminated in the urine except for | 

Answer 48

Doxycycline

Question 49

tetracyline drugs with longer half lives

Answer 49

doxycycline and minocycline

Question 50

what kinds of bacteria do tetracyclines cover

Answer 50

gram (+) and gram (-)

Question 51

type of resistance to tetracyline (2)

Answer 51

 Plasmid-mediated resistance is widespread  Decrease activity of the uptake systems  Development of efflux pumps for active extrusion of the drug

Question 52

drug of choice for vibrio cholera

Answer 52

tetracycline

Question 53

Alternative drug for syphilis | Respiratory infections caused by susceptible organisms

Answer 53

tetracycline

Question 54

Treatment of acne

Answer 54

tetracycline

Question 55

most common tetracycline used for the treatment of acne

Answer 55

doxycycline

Question 56

antibiotic for Leptospirosis

Answer 56

tetracycline/doxycycline

Question 57

Prophylaxis against chronic bronchitis

Answer 57

tetracycline

Question 58

Prophylaxis against malaria

Answer 58

tetracycline

Question 59

Selective uses |  Gastrointestinal ulcers caused by H. pylori

Answer 59

 Tetracycline

Question 60

Selective uses |  Lyme disease

Answer 60

Doxycycline

Question 61

Selective uses |  Meningococcal carrier state

Answer 61

Minocycline

Question 62

Selective uses  Prevention of malaria  Treatment of amoebiasis

Answer 62

 Doxycycline

Question 63

Selective uses  ADH-secreting tumors  Inhibits renal actions of ADH

Answer 63

Demeclocycline

Question 64

``` Identify which drug has this toxicity TOXICITY 1. GI disturbances  Mild nausea and diarrhea to severe, possibly life-threatening colitis  Disturbances in the normal flora  Candidiasis (oral and vaginal)  Bacterial superinfection  S. aureus or C. difficile  Rare ```

Answer 64

tetracyclines

Question 65

``` Identify which drug has this toxicity 2. Bony structures and teeth  Fetal exposure  Tooth enamel dysplasia  Irregularities in bone growth  Contraindicated in pregnancy  Younger children (under age 8)  Enamel dysplasia and crown deformation when permanent teeth appears  Bind with calcium and deposit in newly formed bones (impaired long bone formation ) and teeth (discolouration of teeth) ```

Answer 65

tetracyclines

Question 66

Identify which drug has this toxicity 3. Hepatic toxicity  High doses in pregnant women and those with preexisting renal disease may impair liver function  Hepatic necrosis

Answer 66

tetracyclines

Question 67

Identify which drug has this toxicity | Hepatic toxicity - Hepatic necrosis

Answer 67

tetracyclines

Question 68

``` Identify which drug has this toxicity 4. Renal toxicity  Fanconi’s syndrome  Renal tubular acidosis  Intake of outdated tetracycline ```

Answer 68

tetracyclines

Question 69

Identify which drug has this toxicity 4. Vestibular toxicity  Doxycycline and minocycline  Dose-dependent reversible dizziness and vertigo

Answer 69

tetracyclines

Question 70

3. Photosensitivity  Demeclocycline  Enhanced skin sensitivity to ultraviolet light

Answer 70

tetracyclines

Question 71

Rare GI disturbance caused by tetracycline

Answer 71

bacterial superinfection

Question 72

GI disturbance caused by tetracycline

Answer 72

 Mild nausea and diarrhea to severe, possibly life-threatening colitis  Disturbances in the normal flora  Candidiasis (oral and vaginal)  Bacterial superinfection

Question 73

Toxicity in Bony structures and teeth caused by tetracycline

Answer 73

2. Bony structures and teeth  Fetal exposure  Tooth enamel dysplasia  Irregularities in bone growth  Younger children (under age 8) Enamel dysplasia and crown deformation when permanent teeth appears  (impaired long bone formation ) (discolouration of teeth)

Question 74

3. Hepatic toxicity of tetracycline

Answer 74

hepatic necrosis |  High doses in pregnant women and those with preexisting renal disease may impair liver function

Question 75

renal toxicity in tetracycline

Answer 75

Fanconi's syndrome

Question 76

 Renal tubular acidosis |  Intake of outdated tetracycline

Answer 76

 Fanconi’s syndrome

Question 77

Enhanced skin sensitivity to ultraviolet light caused by which tetracycline

Answer 77

Demeclocycline

Question 78

 |  which 2 AB causes Dose-dependent reversible dizziness and vertigo

Answer 78

Doxycycline and minocycline

Question 79

inhibition of transpeptidation by chloramphenicol is catalyzed by

Answer 79

peptidyl transferase

Question 80

mode of excretion of chloramphenicol

Answer 80

urine

Question 81

Rarely used as a systemic drug

Answer 81

chloramphenicol

Question 82

drug that becomes bactericidal for some strains

Answer 82

chloramphenicol

Question 83

drug that is commonly used as topical agent (As its clinical use)

Answer 83

chloramphenicol

Question 84

cytopenia caused by chloramphenicol is ___-dependent

Answer 84

dose dependent

Question 85

cytopenia caused by chloramphenicol is reversible or irreversible

Answer 85

reversible

Question 86

multivalent cations

Answer 86

Ca, Fe, Al

Question 87

if a patient has gonorrhea, he also has

Answer 87

chlamydia