Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Pharm Exam 4 > Macrolides and Fluoroquinones > Flashcards

Macrolides and Fluoroquinones Flashcards

1
Q

Macrolides are what general antibiotic type and for what are they named?

A

Protein synthesis inhibitors

Named for large macrolide ring structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a prototype macrolide?

A

Erythromycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What drug does Erythromycin act like in its antibacterial activity?

A

Penicillin, which is a cell wall inhibitor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 2 new macrolides that are semisynthetic with an extended spectrum and improved pharmacokinetics?

A

Azithromycin

Clarithromycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the 2 new macrolides, Azithromycin and Clarithromycin used for?

A

Alternatives to penicillins for prophylaxis of bacterial endocarditis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What structure in the Macrolide makes it easily hydrolyzed in the stomach and thereby inactivating a large part of the drug?

A

The lactone ring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the erythromycin spectrum of activity (bacteriostatic/cidal), what bacteria is it active against?

A

Narrow spectrum
Bacteriostatic
Gram Positive Cocci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the spectrum of activity for Azithromycin and Clarithromycin?

A

somewhat broader, to include activity against gram negatives like H. influenza

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the macrolide mechanism of action?

A

bind to 50S bacterial ribosome subunit to inhibit ribosomal translocase activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does inhibiting translocase activity of the 50S subunit mean?

A

It stops transfer of nascent peptide from A site to P site which stop the next amino acid from being added

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Can Erythromycin be bacteriocidal?

A

Yes, depending on concentration of developing bacterial resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is good about narrow spectrum in antibiotics?

A

It reduces the risk of developing bacterial resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the drawback of erythromycin’s method of delivery and how is it avoided?

A

Destroyed by stomach acid so give w/ enteric coating or as ester salt (estolate, state)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the major difference in Azithromycin and Clarithromycin from Erythromycin?

A

Azithromycin and Clarithromycin are not sensitive to stomach acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

If bacteria are resistant to Erythromycin, Azithromycin, Clarithromycin, what does that mean for other drugs that bind the 50S subunit?

A

Bacteria are most likely resistant to those as well

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the other two 50S subunit binding protein synthesis inhibitor antibiotics?

A

Clindomycin

Chloramphenicol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Of Erythromycin, Azithromycin, and Clarithromycin: which has the longest half-life?

A

Azithromycin (60-70 hrs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What cells do Azithromycin and Clarithromycin concentrate in?

A

Macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Azithromycin and Clarithromycin, due to their concentration in Macrophages, are useful against what opportunistic infection commonly found in HIV and immunocompromised patients?

A

Mycobacterium avium intracellulaire

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Where is erythromycin metabolized?

A

Liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the positive with the longer half-lives of Azithromycin and Clarithromycin?

A

Require dosing only 1-2 times/day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Most common side effects of Macrolides (erythromycin, azithromycin, clarithromycin)?

A

Gi disturbances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What metabolism do macrolides mess with leading to their drug interactions?

A

Inhibit cytochrome P450 drug metabolism by liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How is Azithromycin metabolized?

A

In urine and bile, so it is safe for a person with liver disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the most common mechanism for resistance to Macrolides in bacteria?
Plasmids encoding erythromycin efflux transporters or methylation enzymes
26
What is Macrolide dosing for endocarditis prophylaxis that Dr. Ritter gave?
500 mg, 30-60 mins before surgery
27
What is a rare risk factor associated with erythromycin?
Cholestatic jaundice from ester salts of erythromycin interrupting bile flow
28
What Penicillin Class is Erythromycin similar to?
Penicillin G
29
When would a macrolide be indicated?
Patient with penicillin allergy | Bacteria is penicillin resistant
30
What are 2 infections macrolides are commonly used to treat?
Respiratory (pneumonia, mycoplasm, Legionella) Skin
31
What is a prototype Fluoroquinolone?
Ciprofloxacin
32
What are 3 major advantages of Fluoroquinolones?
Oral effectiveness Activity toward gram positive and gram negative Safe
33
Is Ciprofloxacin (fluoroquinolone) bacteriocidal or bacteriostatic? What bacteria is it effective against?
Bacteriocidal | Gram Positive and Gram Negative
34
What is the method of action of Fluoroquinolone?
Inhibit DNA replication by inhibiting bacterial enzyme DNA gyrase
35
Bacterial DNA gyrase is related to what in humans and what are their purposes?
Human DNA topoisomerases | Relieve buildup of torsional strain during DNA replication
36
What is an administration consideration with fluoroquinolones?
don’t take with dairy or antacids because they bind divalent and trivalent metal cations(like tetracyclines do as well)
37
Which fluoroquinolone is useful for the treatment of UTIs because it does not have as good tissue penetration as Ciprofloxacin and Ofloxacin?
Norfloxacin
38
What can block the excretion of fluoroquinolones?
Probenecid (used in war to prolong supplies of penicillin [internet])
39
What is huge contraindiction for using fluoroquinolones?
Do not use in pregnant/nursing women or children under 18 due to potential to damage growing cartilage (Achilles tendon rupture)
40
What is a notable drug interaction for fluoroquinolones?
They increase plasma levels of warfarin
41
Which quinolone (older group) is used only for UTIs?
Nalidixic Acid
42
Large Glycopeptide druge whose most important use is treatment of Methicillin Resistant Staphylococcus infections (MRSA)
Vancomycin
43
Is vancomycin bactericidal or static?
bactericidal
44
What is vancomycin's method of action?
inhibit cell wall synthesis but by different mechanism than penicillin
45
What is vancomycin the DOC for?
Treating pseudomembranous colitis from clindamycin
46
What are 2 methods of administration for vancomycin and is it absorbed systemically?
Intravenous (IV) Orally (125 mg 4/day) No systemic absorption
47
How is vancomycin excreted?
Kidney
48
What are 2 side effect risks from vancomycin?
Ototoxicity | Nephrotoxicity
49
What is the mechanism of action for bacitracin?
Inhibit transport of building blocks of cell wall to outside cell membrane
50
What is the clinical use of bacitracin?
Topical treatment of skin & eye bacterial infections
51
With what drugs is bacitracin used in combination?
Polymyxin B and Neomycin
52
Clindamycin is an alternative drug for what?
Alternative to amoxicillin for endocarditis prophylaxis
53
What is the dosing of Clindamycin before surgery for endocarditis prophylaxis?
600 mg 30-60 min before surgery
54
Given how good it is against anaerobes, when should Clindamycinbe be used?
Late phase dental infections (bacteroides, prevotella, porphyromonas, fusobacterium)
55
For what is Clindamycin the DOC?
Anaerobic infections (e.g. B. fragilis)
56
What are 3 protein synthesis inhibitor drugs that are alternatives to amoxicillin for prophylaxis of endocarditis?
Azithromycin Clarithromycin Clindamycin
57
What is the major risk with Clindamycin?
Enterocolitis due to C. diff overgrowth (superinfection)
58
What is the drug used to treat the superinfection caused by Clindamycin?
Vancomycin (vancomycin vanquishes the turds)
59
What are two drugs other than Nalidixic acid and Norfloxacin that are used for UTIs?
Nitrofurantoin | Methenamine
60
Which five drugs are used to treat M. tuberculosum?
1. Isoniazid 2. Ethambutol 3. Rifampin/Rifampicin 4. Pyrazinamide 5. Streptomycin
61
Which are the three major agents used to treat M. tuberculosum?
1. Isoniazid 2. Ethambutol 3. Rifampin
62
What is THE major agent used for M. tuberculosum
Isoniazid
63
Isoniazid has hepatotoxicity when paired with what other Tb drug?
Rifampin/Rifampicin
64
What is the mechanism of action for methambutol?
inhibits synthesis of tubercle bacilli cell wall component
65
What is the mechanism of action for Rifampin?
inhibits DNA-dependent RNA polymerase
66
What is the tuberculosis drug that is an inducer of hepatic microsomal drug-metabolizing enzymes leading to many drug-drug interactions?
Rifampin
67
Why should you use a drug cocktail to treat tuberculosis?
Tuberculosis is slow growing with high mutation and resistant rates.

Pharm Exam 4 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions