Beta Lactams & Cell Wall Synthesis Inhibitors Flashcards

comprehensive

1
Q

An antimicrobial drug that can eradicate an infection in the absence of host defense mechanisms; kills bacteria.

A

Bactericidal

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2
Q

An antimicrobial drug that inhibits antimicrobial growth but requires host defense mechanisms to eradicate the infection; does not kill bacteria.

A

Bacteriostatic

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3
Q

Drugs with structures containing a beta-lactam ring: includes the penicillins, cephalosporins and carbapenems. This ring must be intact for antimicrobial action.

A

Beta-lactam antibiotics

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4
Q

Bacterial enzymes (penicillinases, cephalosporinases) that hydrolyze the beta-lactam ring of certain penicillins and cephalosporins.

A

Beta-lactamases

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5
Q

Potent inhibitors of some bacterial beta-lactamases used in combinations to protect hydrolyzable penicillins from inactivation.

A

Beta-lactam inhibitors

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6
Q

Lowest concentration of antimicrobial drug capable of inhibiting growth of an organism in a defined growth medium.

A

Minimal inhibitory concentration (MIC)

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7
Q

Bacterial cytoplasmic membrane proteins that act as the initial receptors for penicillins and other beta-lactam antibiotics.

A

Penicillin-binding proteins (PBPs)

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8
Q

Chains of polysaccharides and polypeptides that are cross-linked to form the bacterial cell wall

A

Petptidoglycan

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9
Q

More toxic to the invader than to the host; a property of useful antimicrobial drugs.

A

Selective toxicity

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10
Q

Bacterial enzymes involved in the cross-linking of linear peptidoglycan chains, the final step in cell wall synthesis.

A

Transpeptidases

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11
Q

What are the examples of bacteriostatic drugs?

A
  • Chloramphenicol
  • Erthryomycin
  • Clindamycin
  • Sulfonamides
  • Trimethoprim
  • Tetracyclines
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12
Q

What are the examples of bactericidal drugs?

A
  • Aminoglycosides
  • Beta-lactams
  • Vancomycin
  • Quinolones
  • Rifampin
  • Metronidazole
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13
Q

What are the strategies stated in chemotherapeutic agents?

A
  1. Use of adjunctive agents that can protect against antibiotic inactivation
  2. Use of antibiotic combinations
  3. Introduction of new (and often expensive) chemical derivatives of established antibiotics
  4. Efforts to avoid indiscriminate use or misuse of antibiotics
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14
Q

What are the major Beta-lactam antibiotics that inhibit cell wall synthesis?

A
  • Penicillins
  • Cephalosporins
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15
Q

Beta-lactams have the unusual _ member ring that is common to all members.

A

4-member ring

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16
Q

What are the general structure of cephalosporins?

A
  • Acyc side chain
  • Beta-lactam ring
  • Dihydrothiazine ring
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17
Q

True or False:

Beta-lactam antibiotics are most effective, widely used, and well-tolerated.

A

True

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18
Q

What are the not as important beta-lactam drugs?

A
  • Vancomycin
  • Fosfomycin
  • Bacitracin
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19
Q

These are the drugs that inhibits the growth/replication or kill microorganisms, they are classified under chemotherapeutic drugs.

A

Antimicrobials

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20
Q

What are the following components in bacterial structure?

A
  • Cell membrane
  • Cell wall
  • Nucleus
  • Fimbriae
  • Pili
  • Ribosomes
  • Capsule
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21
Q

What are the components of peptidoglycan bacterial cell wall?

A
  • N-acetylglucosamine (NAG)
  • N-acetylmuramic acid (NAM)
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22
Q

Identify if Gr(+) or Gr(-):

Thick peptidoglycan

A

Gr(+)

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23
Q

Identify if Gr(+) or Gr(-):

Thin peptidoglycan

A

Gr(-)

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24
Q

True or False:

Peptidoglycans are slightly more hydrophilic compared to the outer membrane.

A

True

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25
Q

True or False:

Peptidoglycans are composed of repeating units of N-acetylmuramic acid and N-acetylglucosamine.

A

True

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26
Q

What are the 4 amino acids that composed the tetrapeptide cross-links?

A
  1. L-alanine
  2. D-glutamine
  3. L-lysine
  4. D-alanine
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27
Q

True or False:

The groups under miscellaneous in the bacterial cell wall synthesis inhibitors do not have β-lactam rings.

A

True

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28
Q

True or False:

If bacteria do not have cell walls or cannot regenerate their cell walls, they will be susceptible to our immune system.

A

True

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29
Q

What are the core structures of four β-lactam antibiotic families?

A
  1. Penicillin
  2. Cephalosporin
  3. Monobactam
  4. Carbapenem
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30
Q

What are the β-lactam antibiotics under Penicillins?

A
  • Penicillin G
  • Penicillin V
  • Methicillin
  • Nafcillin
  • Oxacillin
  • Cloxacillin
  • Dicloxacillin
  • Amoxicillin
  • Carbenicillin
  • Ticarcillin
  • Pepracillin
  • Mezlocillin
  • Cefoxitin
  • Aziocillin
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31
Q

What are the 1st generation antibiotics under Cephalosporins?

A
  • Cefazolin
  • Cefadroxil
  • Cephalexin
  • Cephalothin
  • Cephapirin
  • Cephradine

“FA/PHA”

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32
Q

What are the 2nd generation antibiotics under Cephalosporins?

A
  • Cefaclor
  • Cefamandole
  • Cefonicid
  • Cefuroxime
  • Cefprozil
  • Loracarbef
  • Ceforanide
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33
Q

What are the 3rd generation antibiotics under Cephalosporins?

A
  • Cefoperazone
  • Cefotaxime
  • Ceftazidime
  • Ceftizoxime
  • Ceftriaxone
  • Cefixime
  • Cefpodoxime proxetil
  • Cefdinir
  • Cefditoren pivoxil
  • Ceftibuten
  • Moxalactam
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34
Q

What is the 4th generation antibiotic under Cephalosporins?

A

Cefepime

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35
Q

What is the 5th generation antibiotic under Cephalosporins?

A

Ceftobiprole

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36
Q

He suggest that a Penicillium mold must secrete an antibacterial substance.

A

Alexander Flemming

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37
Q

What is the derivative of Penicillin?

A

6-aminopenicillanic acid

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38
Q

Penicillin is excreted via:

A

Urine

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39
Q

What is the basic structure of Penicillins?

A
  1. Thiazolidine ring
  2. β-lactam ring (carries secondary amino group)
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40
Q

Penicillin pharmacokinetics:

Vary in their __ bioavailability.

A

oral

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41
Q

Penicillin pharmacokinetics:

UTIs are usually caused by Gr(_) bacteria.

A

Gr(-)

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42
Q

Penicillin pharmacokinetics:

Penicillin are _ and not _ extensively.

A

polar; matabolized

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43
Q

Penicillin pharmacokinetics:

Penicillins are excreted unchanged in urine through what type of filteration?

A
  1. Glomerular filtration
  2. Tubular filtration
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44
Q

Penicillin pharmacokinetics:

Tubular execretion is inhibited by:

A

Probenecid

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45
Q

Penicillin pharmacokinetics:

What are the two drugs that cross the BBB when meninges are inflamed, given IM, has long half-lives, and released slowly?

A
  • Procaine
  • Benzathine penicillin G
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46
Q

Penicillin pharmacokinetics:

Penicillin must be given on an empty stomach due to its gastric acidity, except:

A

Amoxicillin

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47
Q

Penicillin pharmacokinetics:

Nafcillin is primarily cleared by _ excretion.

A

billiary

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48
Q

What are the mechanism of action in Penicillin?

A
  1. Bactericidal drugs
  2. Inhibit cell wall synthesis
  3. Inhibit bacterial growth by interfering with the transpeptidation reaction
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49
Q

What are the mechanism of resistance against Penicillin?

A
  1. Hydrolysis of β-lactam ring by bacterial β-lactamases (inactivation)
  2. Modification of PBP
  3. Changes in membrane permeability
  4. Antibiotic efflux
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50
Q

Penicillin resistance:

What is the most common mechanism of resistance in Penicillin?

A

β-lactamase production

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51
Q

Penicillin resistance:

Resistance due to impaired penetration of antibiotics occurs only in Gr(_) species.

A

Gr(-) species

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52
Q

Penicillin resistance:

Gr(-) organisms may produce an ___ ___, which consists of cytoplasmic and periplasmic protein components that efficiently transport some β-lactam antibiotics from the periplasm back across the cell wall outer membrane.

A

efflux pump

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53
Q

Clinical uses of Penicillin:

Oral penicillins should be given _ hours before or after a meal; they should not be given with food to minimize binding to food proteins and acid inactivation.

A

1-2 hours

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54
Q

Clinical uses of Penicillin:

Probenecid impairs renal tubular secretion of weak acids such as β-lactam compounds and should be be administered _ g every _ hours orally.

A

0.5 g; 6 hours orally

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55
Q

What are the Narrow Spectrum Penicillinase Susceptible Agents?

A
  1. Penicillin G
  2. Penicillin V
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56
Q

Identify if Penicillin G or V:

  • Limited spectrum
  • Susceptible to β-lactamases
A

Penicillin G

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57
Q

Identify if Penicillin G or V:

  • Oral counterpart of Penicillin G
  • Use for prophylaxis against bacterial endocarditis among patients with valvular heart disease
A

Penicillin V

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58
Q

Penicillin G is used for:

A
  • Streptotocci (sore throats)
  • Meningococci (meningitis)
  • Gram-positive bacilli
  • Spirochetes (Treponema pallidum)
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59
Q

What is the first line of drug for syphilis and is administered intramuscularly?

A

Benzathine Penicillin G

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60
Q

What type of Penicillin G is used for treating β-hemolytic streptococcal pharyngitis and is given once every 3-4 weeks to prevent reinfection?

A

Benzathine penicillin

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61
Q

What type of Penicillin G is commonly used for treating pneumococcal pneumonia and gonorrhea; however it is now rarely used?

A

Procaine penicillin G

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62
Q

Penicillin V is indicated only in minor infections due to its:

A
  1. Poor bioavailability
  2. Need for dosing 4 times a day
  3. Narrow antibacterial spectrum
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63
Q

What are the Very-narrow-spectrum penicillinase-resistant agent that is used against Staphylococcus aureus?

A
  • Methicillin
  • Oxacillin
  • Cloxacillin (Dicloxacillin)
  • Nafcillin

MOCN

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64
Q

What is the half-life of Very-narrow-spectrum penicillinase-resistant agent?

A

Shorter half-lives

Given 4 times a day, every 6 hours.

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65
Q

This very narrow spectrum penicillase is suitable for treating mild to moderate localized staphylococcal infections.

A

Isoxazolyl Penicillins (Dicloxacillin)

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66
Q

Isoxazolyl Penicillins (Dicloxacillin) are _ (acid, basic) stable penicillins and have a reasonable bioavailability.

A

Acid-stable

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67
Q

It is the first antistaphylococcal penicillin to be developed no longer used clinically due to high rates of adverse effects.

A

Methicillin

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68
Q

What is the drug of choice for serious staphylococcal infections such as endocarditis?

A

Oxacillin and Nafcillin

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69
Q

What are the Wider spectrum penicillinase-susceptible agent?

A
  • Ampicillin
  • Amoxicillin
  • Piperacillin
  • Ticarcillin
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70
Q

These are wider spectrum than Penicillin G, and enhanced when used with penicillaneses (BLIC).

A

Amoxicillin and Ampicillin

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71
Q

Route of administration:

Ampicillin is given _ because it degrades in the stomach.

A

IV

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72
Q

Route of administration:

Amoxicillin is given _.

A

orally

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73
Q

These are enhanced selectivity against Gr(-), usually combined with penicillinase inhibitors, and administered through IV.

A

Piperacillin and Ticarcillin

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74
Q

Piperacillin and Ticarcillin enhanced selectivity against Gr(-):

A
  • Pseudomonas
  • Enterobacter
  • Klebsiella
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75
Q

What are the Extended-Spectrum Penicillins?

A
  • Aminopenicillins
  • Carboxypenicillins
  • Ureidopenicillins
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76
Q

What is the function of Extended-Spectrum Penicillins?

A

Enhanced ability to penetrate the Gr(-) outer membrane, and inactivated by many β-lactamases.

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77
Q

Amoxicillin is given in what route of administration?

A

Orally

250-500 mg

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78
Q

Amoxicillin is used to treat:

A
  • Bacterial sinusitis
  • Otitis
  • Lower respiratory tract infection
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79
Q

What are the penicillin drugs that are most active of the oral β-lactam antibiotics against pneumococci with elevated MICs and is preferred β-lactam antibiotics for treating infections susespected to be caused by these strains?

A

Amoxicillin and ampicillin

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80
Q

Ampicillin is effective against susceptible strains of:

A

Shigella

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81
Q

Ampicillin is useful for treating serious infectious caused by susceptible organisms at dosages of 4-12g/d intravenously, including:

A
  • Anaerobes
  • Enterococci
  • Lisera monocytogenes
  • E. coli
  • Salmonella sp
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82
Q

True or False:

Ampicillin can still be used for empiric therapy of UTI and typhoid fever due to the production of β-lactamases by Gr(-) bacilli.

A

False

Cannot be used.

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83
Q

Ampicillin are not active against:

A
  • Klebsiella sp
  • Enterobacter sp
  • Pseudomonas aeuroginosa
  • Citrobacter sp
  • Serratia marcescens
  • Indole-positive Proteus species
84
Q

What are the toxicity/adverse effects of Penicillins?

A
  • Allergy
  • GI disturbances
85
Q

True or False:

If a patient has an allergic reaction to Amoxicillin, then they are also allergic to Ampicillin and Oxacillin. This is the cross-reactivity of penicillins.

A

True

86
Q

Large doses of pencillins given orally may lead to:

A

GI disturbances

Gastrointestinal upset

87
Q

GI disturbances is associated with the development of colitis due to what type of infection?

A

Clostridioides difficile infection

88
Q

Adverse effect of interstitial nephritis is associated with:

A

Methicillin

89
Q

Adverse effect of neutropenia is associated with:

A

Nafcillin

90
Q

Adverse effect of skin rashes in the setting of viral illness associated with:

A

Ampicillin

91
Q

Adverse effect of hepatitis is associated with:

A

Oxacillin

92
Q

The greater incidence of acute kidney injury when combined with vancomycin is associated with:

A

Piperacillin-tazobactam

93
Q

Penicillin skin testing may also be used to evaluate what type of hypersensitivity?

A

Type I hypersensitivity

94
Q

Who was the pharmacologist that isolated Cephalosporin C compound from the fungus Acremonium?

A

Giuseppe Brotzu

95
Q

The fungus Acremonium, previously known as “Cephalosporium” was found in the:

A

Sea near a sewage outfall in Su Siccu, by Cagliari harbo in Sardinia, Italy

96
Q

What is the derivatives of Cephalosporins?

A

7-aminocephalosporanic acid

97
Q

True or False:

Cephalosporins are more stable to many bacterial β-lactamases.

A

True

98
Q

True or False:

Cephalosporins is not active against Listeria monocytogenes.

A

True

99
Q

True or False:

Only ceftaroline has some activity against Enterococci.

A

True

100
Q

True or False:

Cephalosporins have two sites of attachment for various R1 and R2 groups.

A

True

101
Q

What is the function of 7-position in Cephalosporins structure?

A

Alters antibacterial activity

102
Q

What is the function of 3-position in Cephalosporins structure?

A

Modifies pharmacokinetic profile

103
Q

Cephalosporins pharmacokinetics:

What is the route of administration of Cephalosporins?

A

IV

104
Q

Cephalosporins pharmacokinetics:

Major elimination is through:

A

Renal excretion

105
Q

Cephalosporins pharmacokinetics:

What are the drugs that excretes through the bile?

A
  • Cefoperazone
  • Ceftriaxone

3rd generation drugs.

106
Q

Cephalosporins pharmacokinetics:

What are the generations that do not cross BBB even in inflamed meninges?

A

1st and 2nd generation

107
Q

Cephalosporins pharmacokinetics:

The older generation is administered:

A

orally

108
Q

Cephalosporins pharmacokinetics:

The newer generation is administered through:

A

IV or IM

109
Q

What is the mechanism of action and resistance of Cephalosporins?

A
  1. Bind to PBP
  2. Bactericidal
  3. Structural differences render them less susceptible to penicillinases produced by staphylococci
  4. MRSA: Resistant
110
Q

What are the toxicity/adverse effects on Cephalosporins?

A
  • Allergy (rashes to anaphylactic shock)
  • Complete cross-reactivity
111
Q

What is the percentage of cross-reactivity between penicillin and cephalosporin?

A

5-10%

112
Q

These 1st generation drugs are very active against Gr(+) cocci such as streptococci and staphylococci, E.coli, and K. pneumoniae

A
  • Cefazolin
  • Cephalexin
113
Q

1st generation drugs:

Cephalexin is administered:

A

orally

114
Q

1st generation drugs:

Cefazolin is administered:

A

intravenously

115
Q

What are the coverage of 1st generation cephalosporins drugs?

A
  • Gr(+) cocci
  • E.coli
  • K. pneumoniae
  • Proteus mirabilis
116
Q

This first generation drug penetrates well into the bone, has longer duration of action, and a similar spectrum of action compared to other first-generations.

It is also the drug of choice for surgical prophylaxis.

A

Cefazolin

117
Q

These first-generation drugs is administered orally twice daily, a prototype of first generation oral cephalosporins, and effective against pharyngitis.

A
  • Cefadroxil
  • Cephalexin
118
Q

What are the clinical uses of 1st generation cephalosporins drugs?

A
  • UTIs
  • Staphylococcal/streptococcal infections
  • Cellulitis
  • Soft tissue abscess
119
Q

What is the coverage of 2nd generation cephalosporins drugs?

A
  • Same as 1st gen
  • Extended Gr(-) activity
  • Klebsiella
  • H. influenzae
  • Bacteroides fragilis
  • Serratia
120
Q

What are the second-generation drugs that have anaerobic coverage, and is active against Serratia and B. fragilis?

Anaerobic:

  • Peritonitis
  • Diverticulitis
  • Pelvic inflammatory disease
A

Cefotetan
Cefoxitin

121
Q

This second-generation drug has longer half-life, crosses the BBB and can be used for community-acquired bronchitis or pneumonia in the elderly and for immunocompromised.

A

Cefuroxime sodium

122
Q

This second-generation drug is administered twice daily, well-absorbed, and active against β-lactamase-producing organisms.

A

Cefuroxime axetil

123
Q

This second-generation drug improves stability in the presence of extended-spectrum β-lactamases produced by E.coli and Klebsiella sp.

A

Cefoxitin

124
Q

What are the second-generation drugs that are active against H. influenzae?

A
  • Cefuroxime
  • Cefaclor
125
Q

2nd generation drugs:

Cefuroxime is administered:

A

orally

126
Q

What are the coverage of 3rd generation cephalosporins drugs?

A
  • Expanded Gr(-)
  • Citrobacter
  • S. marcescens
  • P. aeruginosa (by ceftazidime only)
  • Providencia
  • β-lactamase-producing strains of Haemophilus and Neisseria
127
Q

This third-generation drug is the regimen of choice for treating most gonococcal infections, and excreted through the bile.

A

Ceftriaxone

128
Q

What is the third-generation drug that penetrated well into the CSF?

A

Cefotaxime

129
Q

What are the third-generation drugs that is administered orally once daily?

A
  • Cefdinir
  • Cefixime
130
Q

What are the clinical uses of 3rd generation cephalosporins drugs?

A

Treat serious infections caused by organisms that are resistant to most other drugs.

131
Q

What are the coverage of fourth-generation cephalosporins?

A
  • P. aeruginosa
  • Enterobacteriaceae
  • MRSA
  • S. pneumoniae
  • Haemophilus & Neisseria spp
  • Penicillin-non susceptible stretococci strains
132
Q

True or False:

Cefepime penetrates well into CSF.

A

True

133
Q

4th generation drugs:

Cefepime is excreted through:

A

renal

134
Q

4th generation drugs:

What is the half-life of Cefepime?

A

2 hours

135
Q

What are the clinical uses of 4th generation drugs?

A
  • Enterobacter infections
  • Empiric therapy for pt. with febrile neutropenia
136
Q

This β-lactam drug has monocyclic β-lactam ring. Their spectrum of activity is limited to aerobic Gr(-) organisms.

A

Monobactam

137
Q

What is the only available monobactam?

A

Aztreonam

138
Q

True or False:

Aztreonam has structural similarities with ceftazidime.

A

True

139
Q

True or False:

Aztreonam penetrates well into CSF.

A

True

140
Q

Monobactam:

Aztreonam is administered:

A

intravenously

every 8 hours in a dose of 1-2 g

141
Q

Monobactam:

What is the half-life of Aztreonam?

A

1-2 hours

142
Q

Monobactam:

What are the clinical uses of Monobactam?

A
  • Pneumonia
  • Meningitis
  • Sepsis caused by susceptible Gr(-) pathogens
143
Q

True or False:

Penicillin-allergic patients tolerate Aztreonam without reaction.

A

True

144
Q

What are the Traditional β-lactamase inhibitors?

A
  • Clavulanic acid
  • Sulbactam
  • Tazobactam
145
Q

What are the Novel Non-β-lactam β-lactamase Inhibitors?

A
  • Avibactam
  • Vaborbactam
146
Q

Identify if Traditional or Novel:

Resemble β-lactam-lactam molecules but have weak antibacterial action.

A

Traditional β-lactamase inhibitors

147
Q

Identify if Traditional or Novel:

Can protect hydrolyzable penicillins from inactivation by these enzymes.

A

Traditional β-lactamase inhibitors

148
Q

Identify if Traditional or Novel:

Most active against Amber class A β-lactamases, but not good inhibitors of class C β-lactamases.

A

Traditional β-lactamase inhibitors

149
Q

Identify if Traditional or Novel:

Active against Amber class A and Amber class C β-lactamases.

A

Novel Non-β-lactam β-lactamase Inhibitors

150
Q

What are the Carbapenems available?

A
  • Doripenem
  • Ertapenem
  • Imipenem
  • Meropenem
151
Q

What are the coverage of Carbapenems?

A
  • Gr(-) rods [P. aeruginosa]
  • Gr(+) organisms
  • Anaerobes
152
Q

Carbapenems are resistant to:

A
  • Most β-lactamases
  • ESBL
153
Q

Carbapenemes are administered:

A

intravenously

154
Q

True or False:

Carbapenems penetrates body tissues and fluids including CSF, except for ertapenem.

A

True

155
Q

Carbapenems is excreted through:

A

Renal

156
Q

Identify the carbapenem:

Dosage: 0.5 g in a 1 to 4-hour infusion every 8 hours

A

Doripenem

157
Q

Identify the carbapenem:

Longest half-life (4 hours)

A

Ertapenem

158
Q

Identify the carbapenem:

Not sufficiently active against P.aeruginosa.

A

Ertapenem

159
Q

Identify the carbapenem:

Dosage: once-daily dose of 1 g through IV or IM.

A

Ertapenem

160
Q

Identify the carbapenem:

Has a wide spectrum with good activity against most:

  • Gr(-) rods
  • Gr(+) organisms
  • Anaerobes
A

Imipenem

161
Q

Identify the carbapenem:

Combined with cilastatin, which inhibits dehydropeptidases enzymes in renal tubules.

A

Imipenem

162
Q

Identify the carbapenem:

Dosage: 0.25-0.5 g through IV every 6-8 hours

A

Imipenem

163
Q

Identify the carbapenem:

Similar to imipenem but slightly higher activity against Gr(-) aerobes and slightly lower activity against Gr(+)

A

Meropenem

164
Q

Identify the carbapenem:

Not significantly degraded by renal dehydropeptidase, and does not require an inhibitor.

A

Meropenem

165
Q

Identify the carbapenem:

Dosage: 0.5 g IV every 8 hours

A

Meropenem

166
Q

What are the Glycopeptide Antibiotics?

A
  • Vancomycin
  • Telavancin
  • Dalbavancin and Oritavancin
167
Q

Identify the glycopeptide antibiotics:

Water-soluble and stable for 14 days in the refrigerator following reconstitution.

A

Vancomycin

167
Q

Vancomycin was isolated from the bacterium called?

A

Amycolatopsis orientalis

168
Q

What are the coverages of Vancomycin?

A
  • Bactericidal against Gr(+) and anaerobes (i.e. Enterococcus faecium
  • Active against MRSA
169
Q

What is the mechanism of action of Vancomycin?

A
  1. Binds to D-Ala-D-Ala terminal of nascent peptidoglycan pentapeptide
  2. Inhibits transglycosylase through preventing elongation of peptidoglycan and cross-linking
  3. Weakens peptidoglycan thus making cell susceptible to lysis.
170
Q

What are the resistance of Vancomycin?

A
  • Terminal D-ala is replaced by D-lactate
  • Loss of critical hydrogen bond
  • Loss of activity
171
Q

Vancomycin is administered _ only for the treatment of colitis caused by C. difficile.

A

orally

172
Q

Vancomycin is _ (poorly, fully) absorbed from the intestinal tract.

A

poorly absorbed

173
Q

Vancomycin is widely dristributed in the body including _ tissue.

A

adipose

174
Q

Vancomycin is excreted through:

A

glomerular filtration by 90%

175
Q

What are the adverse reactions associated with Vancomycin?

A
  • Phlebitis
  • Chills & fever
  • Ototoxicity
  • Nephrotoxicity
  • Red man syndrome
176
Q

Red man syndrome is caused by the released of _, and can be prevented by slowing down the adminsitration of Vancomycin.

A

histamine

177
Q

Identify the glycopeptide antibiotics:

Semisynthetic lipoglycopeptide derived from Vancomycin.

A

Telavancin

178
Q

What are the coverage of Telavancin?

A
  • Gr(+)
  • In-vitro activity against many strains with reduced susceptibility to Vancomycin
179
Q

What is the half-life of Telavancin?

A

8 hours

180
Q

What is the mechanism of action of Telavancin?

A
  1. Inhibits cell wall synthesis by binding to D-Ala-D-Ala terminus of peptidoglycan in the growing cell wall.
  2. Increases membrane permeability and disrupts the bacterial cell membrane potential.
181
Q

What are the adverse reactions associated with Telavancin?

A
  • Nephrotoxicity
  • Teratogenic
  • Not administered to a pregnant women
182
Q

Identify the glycopeptide antibiotics:

Semisynthetic lipoglycopeptides derived from teicoplanin.

A

Dalbavancin and Oritavancin

183
Q

What is the mechanism of action of Dalbavancin and Oritavancin?

A
  1. Inhibits cell wall synthesis by binding to D-Ala-D-Ala terminus of peptidoglycan pentapeptide which prevents cross-linking.
  2. Oritavancin disrupts cell membrane permeability and inhibits RNA synthesis.
184
Q

Dalbavancin and Oritavancin have lower MICs against many Gr(+) bacteria, including?

A
  • Methicillin-resistant
  • Vancomycin-resistant S. aureus
185
Q

What is the half-life of Dalbavancin and Oritavancin?

A

Long half-lives; extremely more than 10 days

186
Q

What are the other cell wall or membrane-active agents?

A
  • Daptomycin
  • Fosfomycin
  • Bacitracin
  • Cycloserine
187
Q

Daptomycin is a lipopeptide fermentation product of?

A

Streptomyces roseosporus

188
Q

Daptomycin is excreted through:

A

renal

189
Q

What is the mechanism of action of Daptomycin?

A
  1. Bind the cell membrane via calcium-dependent insertion of its lipid tail
  2. Depolarization of the cell membrane with potassium efflux and rapid cell death.
190
Q

What are the adverse effects of Daptomycin?

A
  • Myopathy
  • Allergic pneumonitis if prolonged therapy for >2 weeks
  • Pulmonary surfactant antagonist, should not be used to treat pneumonia
191
Q

Fosfomycin is an antimetabolite inhibitor of __ __ by covalently binding to the cysteine residue of the active site.

A

enolpyruvate transferase

192
Q

Fosfomycin becomes synergistic (in-vitro) when combined with:

A
  • β-lactam antibiotics
  • Aminoglycosides
  • Fluoroquinolones
193
Q

Fosfomycin is excreted through:

A

renal

194
Q

What are the clinical uses of Fosfomycin?

A
  • Safe for pregnancy
  • Uncomplicated cystitis (UTI)
195
Q

Bacitracin is obtained from the Tracy strain of?

A

Bacillus subtilis

196
Q

What is the mechanism of action of Bacitracin?

A
  1. Inhibits cell wall formation by interfering with dephosphorylation in the cycling of lipid carrier that transfers peptidoglycan subunits to the growing cell wall.
  2. No cross-resistance between other antimicrobial drugs.
197
Q

What are the adverse effects associated with Bacitracin?

A
  • Highly nephrotoxic
  • Associated with hypersensitivity
198
Q

What is the clinical use of Bacitracin?

A

Topical antibiotic (ointment)

199
Q

Cycloserine is produced by?

A

Streptomyces orchidaceous

200
Q

What are the characteristics of Cycloserine?

A
  1. Water-soluble
  2. Unstable at acid pH
201
Q

Cycloserine is the structural analog of?

A

D-Alanine

202
Q

What is the mechanism of action of Cycloserine?

A
  1. Inhibits incorporation of D-Alanine into peptidoglycan pentapeptide by inhibiting alanine racemase.
203
Q

Cycloserine is excreted through:

A

urine

204
Q

What is the clinical use of Cycloserine?

A

Treatment of tuberculosis caused by strains of Mycobacterium tuberculosis resistant to first-line agents.

205
Q

What are the adverse effects associated with Cycloserine?

A
  • Headaches
  • Tremors
  • Acute psychosis
  • Convulsions