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PR3151 Infection: Optimising Prevention & Treatment > Pharmacology > Flashcards

Pharmacology Flashcards

1
Q

Name 2 classes of bacterial cell wall synthesis inhibitors.

A

Beta-lactams, Glycopeptide

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2
Q

Beta lactams bind to the active side of which enzyme?

A

Transpeptidase (penicillin binding protein)

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3
Q

Name 4 types of beta lactams

A

Penicillins, cephalosporins, carbapenems, monobactam

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4
Q

Name the 4 classes of penicillins

A
  1. natural penicillins (Pen G and Pen V),
  2. penicillinase resistant penicillins (cloxacillin, flucloxacillin),
  3. aminopenicillins (amoxicillin, ampicillin),
  4. antipseudomonal penicillins (piperacillin)
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5
Q

Which natural penicillin is administered parenterally?

A

Penicillin G

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6
Q

Syphilis caused by Treponema pallidum can be treated with which penicillin?

A

Penicillin G

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7
Q

Are natural penicillins commonly used against Staphylococcus aureus?

A

No

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8
Q

Which class of penicillin is commonly used against methicillin sensitive Staphylococcus aureus?

A

Penicillinase resistant penicillins

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9
Q

How does methicillin sensitive Staphylococcus aureus acquire resistance against the natural penicillins?

A

They produce penicillinases

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10
Q

Which bacteria is cloxacillin effective against?

A

Methicillin Sensitive Staphylococcus aureus (MSSA)

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11
Q

How are the penicillins mainly cleared?

A

Renal clearance

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12
Q

Name the 2 aminopenicillins

A

Ampicillin, amoxicillin

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13
Q

Are aminopenicillins effective against beta lactamase producing strains of bacteria?

A

No

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14
Q

Which of the aminopenicillins (amoxicillin or ampicillin) has better oral absorption?

A

Amoxicillin

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15
Q

Does aminopenicillins sufficiently cover Pseudomonas and Klebsiella?

A

No

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16
Q

How are aminopenicillins cleared?

A

Renal

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17
Q

How is piperacillin administered?

A

IV

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18
Q

Which class of penicillins has coverage against Pseudomonas, Proteus and Klebsiella?

A

Anti-pseudomonal penicillins (piperacillin)

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19
Q

Name 3 beta lactams-beta-lactamase inhibitor combination drugs.

A
  1. Augmentin (Amoxicillin + clavulanic acid)
  2. Unasyn (ampicillin + sulbactam)
  3. Zosyn (piperacillin + tazobactam)
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20
Q

How do beta-lactamase inhibitors work?

A

They either covalently bind at or near the active site of the β-lactamase and restructures it, permanently inactivating. In doing so, they protects other beta-lactam antibiotics from beta-lactamase catalysis.

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21
Q

Name a microbe that commonly causes nosocomial infections and is resistant to all penicillins.

A

MRSA (methicillin resistant Staphylococcus aureus)

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22
Q

Name at least 2 penicillins related life-threatening allergic reactions.

A
  1. Anaphylaxis
  2. Stevens Johnson syndrome
  3. Toxic epidermal necrolysis
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23
Q

Which generation of cephalosporins does cefazolin and cephalexin belong to?

A

First Generation

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24
Q

Which generation of cephalosporins are primarily administered orally?

A

First and second generation cehalosporins. Cefazolin (first generation) is an exception.

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25
Q

How are the 3rd, 4th and 5th generation cephalosporins administered?

A

Parenterally

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26
Q

Name at least 3 types of microbes against which first and second generation cephalosporins are ineffective?

A

Pseudomonas aeruginosa and
(LAME species)

  • Listeria monocytogenes,
  • Atypicals (Mycoplasma, Chlamydia, Legionella spp.),
  • MRSA, and
  • Enterococcus species
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27
Q

Ceftriaxone belongs to which generation of cephalosporins?

A

Third Gen

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28
Q

Name one cephalosporin from the third and fourth generation each which is effective against Pseudomonas aeruginosa.

A

Third generation – Ceftazidime

Fourth generation - Cefepime

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29
Q

Which generation of cephalosporins has coverage against MRSA?

A

Fifth generation (ceftobiprole, ceftaroline)

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30
Q

How are most cephalosporins cleared?

A

Renal

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31
Q

How is ceftriaxone cleared?

A

Hepatic

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32
Q

Explain the mechanism of resistance underlying MRSA.

A

MRSA expresses an altered penicillin binding protein (PBP2a) with reduced affinity for the penicillins

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33
Q

Name 3 advantages the third generation and fourth generation cephalosporins have over the first and second generations.

A
  1. Higher activity against Gram-negative bacteria
  2. Greater resistance against the beta-lactamase producing strains
  3. Greater CSF penetration
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34
Q

Does cephalosporin have cross reactivity with penicillins?

A

Yes

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35
Q

Does cephalosporin have cross reactivity with penicillins?

A

Yes

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36
Q

Name the class of antibiotics that are commonly used against extended spectrum beta-lactamase (ESBL) producing bacteria?

A

Carbapenems

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37
Q

Name 3 carbapenems.

A
  1. Imipenem,
  2. meropenem,
  3. ertapenem
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38
Q

How are carbapenems administered?

A

Parenterally

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39
Q

Imipenem is combined with __________, which works by __________.

A

cilastatin,

inhibiting dehydropeptidase 1 (DHP1) found in the brush border of the proximal renal tubule. (DHP1 is necessary for the hydrolysis of imipenem. It is not a beta lactamase inhibitor.)

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40
Q

Can carbapenems be used to treat MRSA?

A

No

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41
Q

Which carbapenem has good CSF penetration?

A

Meropenem

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42
Q

Which of the following carbapenems is not effective against Pseudomonas aeruginosa?

A

Ertapenem

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43
Q

Which drug classes of beta lactams have cross reactivity with penicillins?

A

Cephalosporins, carbapenem

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44
Q

Which drug class does aztreonam belong to?

A

Monobactam

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45
Q

Aztreonam is effective against Gram-

A

negative bacteria (no activity against Gram positive and anaerobic microbes)

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46
Q

Does aztreonam have cross-sensitivity to penicillin?

A

No

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47
Q

What are some adverse effects related to the use of penicillins, cephalosporins and carbapenems?

A

GIT related symptoms (vomiting diarrhea), hypersensitivity (Symptoms range in severity, from a minor rash to life-threatening conditions like anaphylaxis)

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48
Q

Vancomycin is useful against Gram ___________

A

Positives

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49
Q

How is vancomycin commonly administered?

A

IV

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50
Q

When is oral vancomycin preferred?

A

Clostridium difficile-associated diarrhea (CDAD) or the more severe antibiotic-associated pseudo-membranous colitis

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51
Q

What is the first line of antibiotics for CDAD?

A

Vancomycin

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52
Q

Vancomycin interferes with cell wall synthesis by inhibiting ___________

A

transglycosylation

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53
Q

Name 3 antibiotics that work by inhibiting bacterial cell wall synthesis, and are effective against MRSA?

A
  1. ceftobiprole (Fifth generation cephalosporins)
  2. ceftaroline (Fifth generation cephalosporins)
  3. Vancomycin
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54
Q

How is vancomycin cleared?

A

Renal

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55
Q

Name 3 adverse effects related to vancomycin

A
  1. Nephrotoxicity,
  2. Ototoxicity,
  3. Red man syndrome
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56
Q

Name 2 key targets of antimicrobials that work by inhibiting bacterial protein synthesis?

A

50S, 30S bacteria ribosomal subunits

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57
Q

Name at least 2 classes of antibiotics which are 30S protein synthesis inhibitors

A

tetracyclines, glycylcycline, aminoglycosides

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58
Q

Name 3 examples of tetracyclines

A

tetracycline, doxycycline, minocycline

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59
Q

Tetracycline prevents binding of ___________ to the A site of mRNA-ribosome complex

A

tRNA

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60
Q

Tetracyclines should not be administered with dairy products or substances that contain divalent and trivalent cations as this would lead to the formation of ___________, which would ___________ the absorption of the drugs.

A

non-absorbable chelates,

reduce

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61
Q

Comment on tetracycline’s antimicrobial coverage

A

It has broad spectrum activity against many Gram-negative and Gram-positive bacteria. It also has coverage against atypical bacteria. It does not have adequate coverage against Pseudomonas aeruginosa and Proteus

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62
Q

How is tigecycine administered?

A

Intravenously (It has poor oral bioavailability unlike the tetracyclines.)

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63
Q

Glycylcyclines (tigecycline) were designed to overcome which two mechanisms of tetracycline resistance?

A

Expression of efflux pumps, and ribosomal protection

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64
Q

Tigecycline is useful in targeting some of the resistant microbes including

A
  1. Methicillin resistant staphylococci (MRSA),
  2. Multidrug-resistant streptococci,
  3. Vancomycin-resistant enterococci (VRE),
  4. useful against carbapenem resistant strains of Extended-spectrum β-lactamase–producing gram-negative bacteria
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65
Q

Name at least 4 adverse effects associated with the use of tetracyclines

A
  1. Gastrointestinal distress (To reduce ulceration, drink plenty of fluids and do not take it before sleep)
  2. Phototoxicity (Like fluoroquinolones)
  3. Superinfection like thrush
  4. Deposition in bone/primary dentition and may cause discoloration of teeth
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66
Q

The use of tetracyline and tigecycline is contraindicated in which populations of patients?

A

Pregnant women,
Breastfeeding women
Children less than 8 years of age

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67
Q

Aminoglycosides are transported across the inner membrane of Gram-negative bacteria by ___________ , which is an energy dependent process.

A

Active transport

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68
Q

Aminoglycosides are particularly effective against _______ Gram-negative bacteria

A

Aerobic

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69
Q

Name 5 examples aminoglycosides

A

gentamicin, streptomycin, tobramycin, amikacin, neomycin

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70
Q

Aminoglycosides demonstrate synergism when combined with which class of antibiotics? Name one class.

A

Beta lactams (e.g. gentamicin and ceftriaxone for the management of staphylococcus endocarditis)

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71
Q

How are aminoglycosides commonly administered?

A

Parenterally (They have poor oral bioavailability)

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72
Q

Name an aminoglycoside that is used in the management of tuberculosis

A

Streptomycin (administered IM)

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73
Q

How are aminoglycosides cleared?

A

Renal

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74
Q

Name at least 2 adverse effects associated with aminoglycosides

A
  1. Ototoxicity
  2. Nephrotoxicity (Do not combine with other nephrotoxicity)
  3. Neuromuscular paralysis (Especially when used with neuromuscular blockers)
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75
Q

Name an aminoglycoside that is administered orally

A

Neomycin (bowel prep)

76
Q

Name 2 groups of patients in whom aminoglycosides would be contraindicated

A
  1. Pregnant women,
  2. Patients suffering from myasthenia gravis because of the risk of prolonged neuromuscular blockade
  3. Patients with severe renal Impairment
77
Q

What are the 6 “NOs” in relation to aminoglycosides?

A
  1. No to protein synthesis
  2. Particularly active against aerobic Gram-Negative Organisms
  3. No to use during pregnancy
  4. No to oral administration
  5. No to CSF penetration
  6. Nephro- and Oto- toxicities
78
Q

Name 3 types of 50S protein synthesis inhibitors

A

Macrolides, clindamycin, linezolid

79
Q

Name 3 macrolides

A

Erythromycin, clarithromycin, azithromycin

80
Q

Are macrolides bacteriostatic or bactericidal antibiotics?

A

Bacteriostatic

81
Q

How can macrolides be administered?

A

Oral and IV

82
Q

Name some of the microbial infections that the macrolides are useful against

A

Respiratory infections caused by S.pneumoniae, H. influenzae and Moraxella catarrhalis and those caused by atypical bacteria such as Legionella pneumophilia, Mycoplasma and Chlamydia
STDs caused by Chlamydia trachomatis and Neisseria gonorrhoea
H.pylori infections

83
Q

Name 2 adverse effects associated with macrolides

A
  1. Gastric Distress
  2. Hepatotoxicity
  3. Ototoxicity
  4. May prolong QT interval
84
Q

How are macrolides cleared?

A

Erythromycin and clarithromycin undergoes hepatic clearance

Azithromycin – is mainly eliminated unchanged in faeces

85
Q

Which of the macrolides cause the most GI distress?

A

Eythromycin

86
Q

Name 2 mechanisms via which bacteria may acquire macrolide resistance

A

ERM gene expression, efflux pumps

87
Q

Which drug(s) can exhibit cross resistance with macrolides?

A

Clindamycin (if the microbes acquire resistance by expressing erm methylases)

88
Q

Linezolid works by ___________

A

It binds the bacterial 23S ribosomal RNA of the 50S subunit and inhibits the formation of the initiation complex needed for protein synthesis.

89
Q

Clindamycin is primarily used to treat _________ infections

90
Q

Can clindamycin be used to treat MRSA?

90
Q

How is clindamycin administered?

91
Q

Name an adverse effect associated with the use of clindamycin

A

Clostridium difficile associated diarrhoea

92
Q

What is linezolid’s mechanism of action?

A

It binds the bacterial 23S ribosomal RNA of the 50S subunit and inhibits the formation of the initiation complex needed for protein synthesis.

93
Q

Linezolid is effective against Gram _________ bacteria?

94
Q

Linezolid binds to bacterial _________ ribosomal RNA of 50S subunit

95
Q

Name 3 antibiotics that only covers Gram positives?

A

Vancomycin, penicillinase resistant penicillin, linezolid

96
Q

How is linezolid administered?

97
Q

What does linezolid cover?

A

Many of the resistant Gram-positive strains such as MRSA, VRE, VRSA

98
Q

Name at least 2 key adverse effects associated with prolonged use of linezolid

A
  1. Irreversible peripheral neuropathies
  2. Optic neuritis
  3. Bone marrow suppression
99
Q

Linezolid can cause _________ if administered concomitantly with SSRI or MAO inhibitors?

A

serotonin syndrome

100
Q

Can linezolid be used for the treatment of catheter-related bloodstream infections?

A

No, it is not approved. (Based on FDA recommendation)

101
Q

Name 2 antibiotics that can be administered orally for MRSA

A

Linezolid and clindamycin

102
Q

Which of the protein synthesis inhibitors are safe for use in pregnant women?

A

Macrolides, clindamycin

103
Q

Fluoroquinolone targets _________ in Gram negatives and _________ in Gram positive bacteria

A

DNA gyrase, topoisomerase IV

104
Q

Name 3 fluoroquinolones

A

ciprofloxacin, levofloxacin, moxifloxacin

105
Q

Fluroquinolones should be administered at least _________ hours before consumption of dairy products or substances that contain divalent cations

A

2 hours

Best on empty stomach

106
Q

Name the two respiratory quinolones

A

Levofloxacin and moxifloxacin

107
Q

Name at least 3 adverse effects associated with the use of fluroquinolones.

A
  1. Phototoxicity
  2. Tendinitis or tendon rupture
  3. Prolong QT interval
  4. Peripheral Neuropathy
  5. GI distress
  6. Arthropathy
108
Q

Which antibiotics are known to cause phototoxicity?

A

Tetracyclines, fluoroquinolones

109
Q

Fluoroquinolones are contraindicated in _________

A
  1. Children < 18 years old
  2. Pregnant women
110
Q

Can fluoroquinolones be used when breastfeeding?

111
Q

Name 3 folate synthesis inhibitors

A

Sulfonamides, trimethoprim, cotrimoxazole

112
Q

Folic acid is vitamin B9 that is needed in humans to produce healthy ___________

A

Red Blood Cells

113
Q

Which enzyme does sulfonamide inhibit?

A

Dihydropteroate synthase

114
Q

Sulfonamides are only effective in bacteria that synthesize their own __________?

A

Folic acid

115
Q

Sulfonamides can cause nephrotoxicity as a result of __________?

A

crystalluria

116
Q

G6PD deficient patients using sulfonamides can suffer from __________

A

hemolytic anemia

117
Q

Usage of sulfonamides in last trimester can cause __________ in newborns

A

kernicterus

118
Q

Which enzyme does trimethoprim inhibit?

A

Dihydrofolate reductase

119
Q

Folic acid deficiency caused by trimethoprim can be managed by giving the patients _____________ .

A

Folinic acid

120
Q

Trimethoprim can cause __________ deficiency in humans

A

folic acid

121
Q

Cotrimoxazole is a combination of which 2 antibiotics, and in what ratio?

A

Trimethoprim and sulfamethoxazole, 1:5 respectively

122
Q

Name an antibiotic which is used as the choice of drug for the management of pneumocystis pneumonia

A

Cotrimoxazole

123
Q

Cotrimoxazole is contraindicated in which trimester(s) of pregnancy?

A

First and last

124
Q

Name at LEAST two indications for cotrimoxazole

A
  1. Uncomplicated UTI
  2. Pneumocystis pneumonia
125
Q

Name at LEAST 3 adverse effects related to the use of cotrimoxazole

A
  1. Glossitis
  2. Rash
  3. Photosensitivity
  4. Blood disorders including megaloblastic anemia, leukopenia, and thrombocytopenia
126
Q

What is nitrofurantoin’s mechanism of action?

A

It is converted by the bacteria to a highly active intermediate, which disrupts the synthesis of DNA, RNA and metabolic processes.

127
Q

Nitrofurantoin is effective in treatment of _________ .

128
Q

Nitrofurantoin can cause urine colour to turn _________ .

129
Q

How is nitrofurantoin cleared?

130
Q

G6PD deficient patients using nitrofurantoin are susceptible to ___________ .

A

Hematologic disturbances such as hemolytic anemia, leukopenia

131
Q

What is G6PD, and why is it important in red blood cells?

A

The glucose-6-phosphate dehydrogenase (G6PD) enzyme is the central factor of the antioxidant defense system in red blood cells, which helps maintain high levels of reduced glutathione (GSH) and nicotine adenine dinucleotide phosphate (NADPH), to protect the RBC from oxidative damage caused by reactive oxygen species.

132
Q

Name 3 groups of patients in whom nitrofurantoin may be contraindicated.

A
  1. Patients with impaired renal function
  2. Pregnant women (at term > 37 weeks)
  3. Infants <1 mth of age
133
Q

What would be examples of recommended treatment options for simple UTI in healthy women of reproductive age?

A
  1. Cotrimoxazole
  2. Nitrofurantoin
134
Q

Name 2 polyenes antifungal

A
  1. Amphotericin B
  2. Nystatin
135
Q

Name the 2 categories of azole antifungals

A
  1. Triazole
  2. Imidazole
136
Q

What is the mechanism of action polyene antifungals?

A

They bind to ergosterol in the plasma membranes of sensitive fungal cells to forms pores (channels). These pores disrupt membrane function, allowing electrolytes and other small molecules to leak from the cell, resulting in cell death.

137
Q

How is amphotericin B commonly administered?

A

IV (poor oral bioavailability)

138
Q

What advantage does the liposomal formulation of amphotericin B has over the conventional deoxycholate formulation?

A

Liposomal formulation has reduced renal toxicity

139
Q

State 2 adverse effects associated with amphotericin B deoxycholate formulation

A
  1. Fever and chills
  2. Nephrotoxicity
140
Q

Name 2 clinical indications for amphotericin B

A

Candidiasis
Aspergilliosis
Cryptococcal meningitis

141
Q

Name an anti-fungal, which is relatively safe for use in pregnancy despite systemic exposure.

A

Amphotericin B

142
Q

What is the mechanism of action for 5-Flucytosine?

A

5-flucytosine is converted, by cytosine deaminase, to its metabolically active form 5-fluorouracil (5-FU), which inhibits protein synthesis and inhibits thymidylate synthase hence inhibiting DNA synthesis.

143
Q

How is 5-Flucytosine commonly administered?

A

Oral (good oral bioavailability)

144
Q

State at least 2 adverse effects associated with the use of 5 flucytosine

A

Bone marrow suppression
Hepatotoxicity
GI related effects

145
Q

State one clinical indication for 5-flucytosine

A

Cryptococcal meningitis (usually in combination with amphotericin B, rarely used as single agent due to resistance)

146
Q

Name 3 echinocandins

A

Caspofungin
Micafungin
Anidulafungin

147
Q

State the mechanism of action of the echinocandins

A

Echinocandins inhibit the activity of the glucan synthase complex, resulting in loss of the structural integrity of the cell wall

148
Q

How are echinocandins commonly administered?

149
Q

Name 2 fungal species against which Echinocandins have potent activity

A
  1. Candida
  2. Aspergillus
150
Q

What is the mechanism of action of azoles?

A

They inhibit C-14 α-demethylase (CYP450 enzyme), thereby blocking the demethylation of lanosterol to ergosterol. This inhibition of ergosterol biosynthesis disrupts membrane structure and function and inhibits fungal cell growth.

151
Q

Do the triazoles have good oral bioavailability?

152
Q

State 3 adverse effects common to the triazoles

A

QT prolongation
Hepatotoxicity
GI side effects

153
Q

Name a triazole which is associated with the adverse effect of cardiotoxicity

A

Itraconazole

154
Q

Name a triazole which is associated with the adverse effect of neurotoxicity

A

Voriconazole

155
Q

Name one class of anti-fungals, which is significantly associated with CYP450 enzymes related drug-drug interactions?

156
Q

Which azole should not be taken with antacids?

A

Itraconazole (low pH improves absorption)

157
Q

Which azole is the treatment of choice for the management of aspergillosis?

A

Voriconazole

158
Q

How are the imidazoles commonly administered?

A

Topical (minimally absorbed)

159
Q

Name 2 anti-fungal drugs that can be used in the management of vuvlovaginal candidiasis and describe how it is administered

A

clotrimazole (cream)
fluconazole (oral)
miconazole (vaginal suppository)
nystatin (vaginal suppository)

160
Q

Is nystatin administered parenterally?

161
Q

State a clinical indication for nystatin, and how it is administered.

A
  1. oropharyngeal candidiasis (oral agent; swish and swallow or swish and spit)
  2. vulvovaginal candidiasis (vaginal suppository)
162
Q

What is terbinafine’s mechanism of action?

A

It inhibits squalene epoxidase, thereby blocking its conversion to lanosterol and biosynthesis of ergosterol, an essential component of the fungal cell membrane.

163
Q

How is terbinafine administered for the management of tinea capitis?

A

Oral (Topical application cannot be used for the management of tinea capitis)

164
Q

What are the first line drugs against tuberculosis?

A

(RIPES)

Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
Streptomycin

165
Q

What is the mechanism of action of rifampicin?

A

Rifampicin inhibits gene transcription of mycobacteria by blocking the DNA-dependent RNA polymerase, which prevents the bacillus from synthesizing messenger RNA and protein, causing cell death.

166
Q

State 2 clinical indications for rifampicin

A
  1. Latent / Active tuberculosis
  2. Leprosy, against Mycobacterium leprae
167
Q

Which organism causes tuberculosis?

A

Mycobacterium tuberculosis

168
Q

Which of the 4 standard first line anti-tuberculosis drugs are safe for use in patients with kidney failure?

A

Rifampicin and Isoniazid

169
Q

Name 3 adverse effects associated with rifampicin

A

Hepatitis
Cutaneous reactions
Gastrointestinal symptoms

170
Q

What is the mechanism of action of isoniazid?

A

Isoniazid is activated by the catalase-peroxidase enzyme of M. tuberculosis. The activation of isoniazid produces oxygen-derived free radicals that can inhibit the formation of mycolic acids of the bacterial cell wall, cause DNA damage and, subsequently, the death of the bacillus.

171
Q

Which enzyme is involved in the metabolism of isoniazid, and presents with wide variation in activity in the community due to genetic polymorphisms?

A

N-acetyl transferase (rapid acetylator vs slow acetylator phenotypes are found in the population due to the genetic polymorphism

172
Q

State 2 adverse effects related to isoniazid

A
  1. Peripheral Neuropathy
  2. Hepatitis
173
Q

Patients on isoniazid are often co-administered _________ to help overcome ________ deficiency to avoid peripheral ________ .

A

pyridoxine, vitamin B6, neuropathy

174
Q

What food – food interactions must patients taking isoniazid be aware for?

A

They should avoid food rich in tyramine and histamine (certain types of fish, cheese and red wine).

175
Q

What is the mechanism of action of pyrazinamide?

A

Pyrazinamide is converted to its active form, pyrazinoic acid, by the microbial enzymes. The accumulation of pyrazinoic acid decreases the intracellular pH to levels that cause the inactivation of critical pathways necessary for the survival of the bacteria.

176
Q

Which of the first line anti-tuberculosis drugs is highly effective against the persistent bacilli

A

Pyrazinamide

177
Q

Which of the 4 standard first line anti-tuberculosis drugs must be avoided or used with caution if the patient suffers from liver disease?

A

(RIP)

Rifampicin
Isoniazid
Pyrazinamide

178
Q

Which of the 4 standard first line anti-tuberculosis drugs (R.I.P.E) is/are highly associated with causing gout like symptoms?

A
  1. Pyrazinamide (More common with pyrazinamide then ethambutol)
  2. Ethambutol
179
Q

Which of the 4 standard first line anti-tuberculosis drugs must be avoided or used with caution if the patient suffers from kidney impairment?

A
  1. Pyrazinamide
  2. Ethambutol
180
Q

What is the mechanism of action ethambutol?

A

Ethambutol inhibits the arabinosyltransferase enzyme and interferes with the polymerization of arabinose into arabinogalactan, the principal polysaccharide on the mycobacterial cell wall.

181
Q

Which of the 4 standard first line anti-tuberculosis drugs (R.I.P.E) is/are highly associated with causing visual toxicity?

A

Ethambutol

182
Q

Which class of antibiotics does streptomycin belong to?

A

Aminoglycoside

183
Q

How is streptomycin administered?

A

Intramuscular injection

184
Q

In which groups of individuals would physicians have a high index of suspicion for multi drug-resistant tuberculosis?

A

Individuals

  1. who were previously treated for TB,
  2. who have failed TB treatment,
  3. who are known contacts of patients with MDR-TB, or
  4. who come from countries with high prevalence of drug resistant tuberculosis

PR3151 Infection: Optimising Prevention & Treatment (10 decks)

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