Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Antibiotics > Antibiotics > Flashcards

Antibiotics Flashcards

(93 cards)

Start Studying
1
Q

Penicillin G,V

Mechanism?

A

D-Ala-D-Ala structural analog. Bind penicillin-binding proteins (transpeptidases).
Block transpeptidase cross-linking of peptidoglycan in cell wall.
Activate autolytic enzymes.

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

Penicillin G,V

Clinical Use?

A

Mostly used for gram ⊕ organisms (S pneumoniae, S pyogenes, Actinomyces). Also used for gram ⊝
cocci (mainly N meningitidis) and spirochetes (mainly T pallidum). Bactericidal for gram ⊕ cocci,
gram ⊕ rods, gram ⊝ cocci, and spirochetes. β-lactamase sensitive.

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

Penicillin G,V

Adverse Effects

A

Hypersensitivity reactions, direct Coombs ⊕ hemolytic anemia, drug-induced interstitial nephritis.

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

Penicillin G,V

Resistance

A

β-lactamase cleaves the β-lactam ring. Mutations in PBPs.

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

Penicillinase-sensitive
penicillins

Examples?

A

Amoxicillin, ampicillin; aminopenicillins

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

Penicillinase-sensitive
penicillins

Mechanisms?

A

Same as penicillin. Wider spectrum;
penicillinase sensitive. Also combine with
clavulanic acid to protect against destruction
by β-lactamase.

AMinoPenicillins are AMPed-up penicillin.
AmOxicillin has greater Oral bioavailability
than ampicillin.

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

Penicillinase-sensitive
penicillins

Clinical Use?

A

Extended-spectrum penicillin—H influenzae,
H pylori, E coli, Listeria monocytogenes,
Proteus mirabilis, Salmonella, Shigella,
enterococci.

Coverage: ampicillin/amoxicillin HHELPSS
kill enterococci.

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

Penicillinase-sensitive
penicillins

Adverse Effects?

A

Hypersensitivity reactions, rash,

pseudomembranous colitis.

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

Penicillinase-sensitive
penicillins

Resistance?

A

Penicillinase (a type of β-lactamase) cleaves

β-lactam ring

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

Penicillinase-resistant
penicillins

Examples

A

Dicloxacillin, nafcillin, oxacillin.

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

Penicillinase-resistant
penicillins

Mechanisms

A

Same as penicillin. Narrow spectrum;
penicillinase resistant because bulky R group
blocks access of β-lactamase to β-lactam ring.

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

Penicillinase-resistant
penicillins

Clinical Use

A

S aureus (except MRSA).

“Use naf (nafcillin) for staph.”

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

Penicillinase-resistant
penicillins

Adverse Effects

A

Hypersensitivity reactions, interstitial nephritis

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

Penicillinase-resistant
penicillins

Resistance

A

MRSA has altered penicillin-binding protein

target site.

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

Antipseudomonal
penicillins

Examples?

A

Piperacillin, ticarcillin.

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

Antipseudomonal
penicillins

Mechanism?

A

Same as penicillin. Extended spectrum. Penicillinase sensitive; use with β-lactamase inhibitors.

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

Antipseudomonal
penicillins

Clinical Use?

A

Pseudomonas spp. and gram ⊝ rods.

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

Antipseudomonal
penicillins

Adverse Effects

A

Hypersensitivity reactions.

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

Cephalosporins

Mechanism

A

β-lactam drugs that inhibit cell wall synthesis
but are less susceptible to penicillinases.
Bactericidal

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

Cephalosporins

What organisms are not covered by 1st-4th generation cephalosporins?

A

Listeria, Atypicals (Chlamydia, Mycoplasma),

MRSA, and Enterococci

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

Clinical Use and examples

1st generation Cephalosporins

A

1st generation (cefazolin, cephalexin)—gram ⊕
cocci, Proteus mirabilis, E coli, Klebsiella
pneumoniae. Cefazolin used prior to surgery to
prevent S aureus wound infections.

1st generation—⊕ PEcK

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

Clinical Use and examples

2nd generation Cephalosporins

A

2nd generation (cefaclor, cefoxitin, cefuroxime,
cefotetan)—gram ⊕ cocci, H influenzae,
Enterobacter aerogenes, Neisseria spp., Serratia
marcescens, Proteus mirabilis, E coli, Klebsiella
pneumoniae.

2nd graders wear fake fox fur to tea parties.
2nd generation—⊕ HENS PEcK

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

Clinical Use and examples

3rd generation Cephalosporins

A 
3rd generation (ceftriaxone, cefotaxime, 
cefpodoxime, ceftazidime)—serious gram ⊝ 
infections resistant to other β-lactams.

Can cross blood-brain barrier.
Ceftriaxone—meningitis, gonorrhea,
disseminated Lyme disease.
Ceftazidime—Pseudomonas.

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

Clinical Use and examples

4th generation Cephalosporins

A 
4th generation (cefepime)—gram ⊝ organisms, 
with increased activity against Pseudomonas and gram 
⊕ organisms.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Clinical Use and examples 5th generation Cephalosporins
5th generation (ceftaroline)—broad gram ⊕ and gram ⊝ organism coverage; unlike 1st–4th generation cephalosporins, ceftaroline covers MRSA, and Enterococcus faecalis—does not cover Pseudomonas.
26
Cephalosporins Adverse effects
Hypersensitivity reactions, autoimmune hemolytic anemia, disulfiram-like reaction, vitamin K deficiency. Low rate of crossreactivity even in penicillin-allergic patients. increase nephrotoxicity of aminoglycosides.
27
Cephalosporins Resistance mechanism?
Inactivated by cephalosporinases (a type of | β-lactamase). Structural change in penicillinbinding proteins (transpeptidases).
28
β-lactamase inhibitors Examples
Include Clavulanic acid, Avibactam, Sulbactam, Tazobactam. Often added to penicillin antibiotics to protect the antibiotic from destruction by β-lactamase. CAST (eg, amoxicillin-clavulanate, ceftazidime-avibactam, ampicillin-sulbactam, piperacillin-tazobactam).
29
Carbapenems Examples
Doripenem, Imipenem, Meropenem, Ertapenem (DIME antibiotics are given when there is a 10/10 [life-threatening] infection).
30
Carbapenems Mechanism What is Imipenem commonly prescribed along with?
Imipenem is a broad-spectrum, β-lactamase– resistant carbapenem. Always administered with cilastatin (inhibitor of renal dehydropeptidase I) to decrease inactivation of drug in renal tubules. With imipenem, “the kill is lastin’ with cilastatin.” Newer carbapenems include ertapenem (limited Pseudomonas coverage) and doripenem
31
Carbapenems Clinical Use
Gram ⊕ cocci, gram ⊝ rods, and anaerobes. Wide spectrum and significant side effects limit use to life-threatening infections or after other drugs have failed. Meropenem has a decrease risk of seizures and is stable to dehydropeptidase I
32
Carbapenems Adverse effects
GI distress, rash, and CNS toxicity (seizures) at | high plasma levels.
33
Carbapenems Mechanism of resistance
Inactivated by carbapenemases produced by, | eg, K pneumoniae, E coli, E aerogenes
34
Monobactams Example
Aztreonam
35
Monobactams Mechanism
Less susceptible to β-lactamases. Prevents peptidoglycan cross-linking by binding to penicillinbinding protein 3. Synergistic with aminoglycosides. No cross-allergenicit
36
Monobactams Clinical Use
Gram ⊝ rods only—no activity against gram ⊕ rods or anaerobes. For penicillin-allergic patients and those with renal insufficiency who cannot tolerate aminoglycosides
37
Monobactams Adverse effects
Usually nontoxic; occasional GI upset
38
Vancomycin Mechanism
Inhibits cell wall peptidoglycan formation by binding D-Ala-D-Ala portion of cell wall precursors. Bactericidal against most bacteria (bacteriostatic against C difficile). Not susceptible to β-lactamases.
39
Vancomycin Adverse Effect
Well tolerated in general but NOT trouble Free. Nephrotoxicity, Ototoxicity, Thrombophlebitis, diffuse Flushing (red man syndrome A idiopathic reaction largely preventable by pretreatment with antihistamines), DRESS syndrome
40
Vancomycin Clinincal Use
Gram ⊕ bugs only—for serious, multidrug-resistant organisms, including MRSA, S epidermidis, sensitive Enterococcus species, and Clostridium difficile (oral dose for pseudomembranous colitis
41
Vancomycin Resistance mechanism
Occurs in bacteria (eg, Enterococcus) via amino acid modification of D-Ala-D-Ala to D-Ala-D-Lac. “If you Lack a D-Ala (dollar), you can’t ride the van (vancomycin).”
42
Name Protein synthesis inhibitor antibiotics? Which are bacteriostatic and which are bactericidal?
``` 30S inhibitors Aminoglycosides Tetracyclines 50S inhibitors Chloramphenicol, Clindamycin Erythromycin (macrolides) Linezolid “Buy AT 30, CCEL (sell) at 50. ``` All are bacteriostatic, except aminoglycosides (bactericidal) and linezolid (variable)
43
Aminoglycosides Mechanism
Bactericidal; irreversible inhibition of initiation complex through binding of the 30S subunit. Can cause misreading of mRNA. Also block translocation. Require O2 for uptake; therefore ineffective against anaerobes
44
Aminoglycosides Clinical Use
Severe gram ⊝ rod infections. Synergistic with β-lactam antibiotics. Neomycin for bowel surgery.
45
Aminoglycosides Adverse Effects
Nephrotoxicity, Neuromuscular blockade (absolute contraindication with myasthenia gravis), Ototoxicity (especially with loop diuretics), Teratogenicity.
46
Aminoglycosides Mechanism of Resistance
Bacterial transferase enzymes inactivate the drug by acetylation, phosphorylation, or adenylation.
47
Aminoglycosides Examples
Gentamicin, Neomycin, Amikacin, Tobramycin, Streptomycin. “Mean” (aminoglycoside) GNATS caNNOT kill anaerobes Nephrotoxicity, Neuromuscular blockade (absolute contraindication with myasthenia gravis), Ototoxicity (especially with loop diuretics), Teratogenicity
48
Tetracycline Mechanism
Bacteriostatic; bind to 30S and prevent attachment of aminoacyl-tRNA. Limited CNS penetration. Doxycycline is fecally eliminated and can be used in patients with renal failure. Do not take tetracyclines with milk (Ca2+), antacids (eg, Ca2+ or Mg2+), or iron-containing preparations because divalent cations inhibit drugs’ absorption in the gut.
49
Tetracycline Clinical Use
Borrelia burgdorferi, M pneumoniae. Drugs’ ability to accumulate intracellularly makes them very effective against Rickettsia and Chlamydia. Also used to treat acne. Doxycycline effective against community-acquired MRSA
50
Tetracycline Adverse effects
GI distress, discoloration of teeth and inhibition of bone growth in children, photosensitivity. Contraindicated in pregnancy
51
Tetracycline Mechanism of Resistance
decrease uptake or increase efflux out of bacterial cells by plasmid-encoded transport pumps.
52
Tigecycline Mechanism
Tetracycline derivative. Binds to 30S, inhibiting protein synthesis. Generally bacteriostatic.
53
Tigecycline Clinical Use
Broad-spectrum anaerobic, gram ⊝, and gram ⊕ coverage. Multidrug-resistant organisms (MRSA, VRE) or infections requiring deep tissue penetration
54
Tigecycline Adverse Effects
GI symptoms: nausea, vomiting
55
Chloramphenicol Mechanism
Blocks peptidyltransferase at 50S ribosomal subunit. Bacteriostatic.
56
Chloramphenicol Clinical Use
Meningitis (Haemophilus influenzae, Neisseria meningitidis, Streptococcus pneumoniae) and rickettsial diseases (eg, Rocky Mountain spotted fever [Rickettsia rickettsii]). Limited use due to toxicity but often still used in developing countries because of low cost.
57
Chloramphenicol Adverse effects
Anemia (dose dependent), aplastic anemia (dose independent), gray baby syndrome (in premature infants because they lack liver UDP-glucuronosyltransferase)
58
Chloramphenicol MECHANISM OF RESISTANCE
Plasmid-encoded acetyltransferase inactivates the drug
59
Clindamycin Mechanism
Blocks peptide transfer (translocation) at 50S | ribosomal subunit. Bacteriostatic.
60
Clindamycin Clinical Use
Anaerobic infections (eg, Bacteroides spp., Clostridium perfringens) in aspiration pneumonia, lung abscesses, and oral infections. Also effective against invasive group A streptococcal infection. Treats anaerobic infections above the diaphragm vs metronidazole (anaerobic infections below diaphragm)
61
Clindamycin Adverse Effects
``` Pseudomembranous colitis (C difficile overgrowth), fever, diarrhea. ```
62
Linezolid Mechanism
Inhibits protein synthesis by binding to 50S subunit and preventing formation of the initiation complex
63
Linezolid Clinical Use
Gram ⊕ species including MRSA and VRE.
64
Linezolid Adverse Effects
Bone marrow suppression (especially thrombocytopenia), peripheral neuropathy, serotonin syndrome (due to partial MAO inhibition)
65
Linezolid Mechanism of Resistance
Point mutation of ribosomal RNA
66
Macrolides Examples
Azithromycin, clarithromycin, erythromycin
67
Macrolides Mechanism
Inhibit protein synthesis by blocking translocation (“macroslides”); bind to the 23S rRNA of the 50S ribosomal subunit. Bacteriostatic
68
Macrolides Clinical Use
``` Atypical pneumonias (Mycoplasma, Chlamydia, Legionella), STIs (Chlamydia), gram ⊕ cocci (streptococcal infections in patients allergic to penicillin), and B pertussis. ```
69
Macrolides Adverse Effects
MACRO: Gastrointestinal Motility issues, Arrhythmia caused by prolonged QT interval, acute Cholestatic hepatitis, Rash, eOsinophilia. Increases serum concentration of theophylline, oral anticoagulants. Clarithromycin and erythromycin inhibit cytochrome P-450
70
Macrolides Mechanism of Resistance
Methylation of 23S rRNA-binding site prevents binding of drug
71
Polymyxins EXAMPLE
Colistin (polymyxin E), polymyxin B
72
Polymyxins Mechanism
Cation polypeptides that bind to phospholipids on cell membrane of gram ⊝ bacteria. Disrupt cell membrane integrity Ž leakage of cellular components Ž cell death
73
Polymyxins Clinical Use
Salvage therapy for multidrug-resistant gram ⊝ bacteria (eg, P aeruginosa, E coli, K pneumoniae). Polymyxin B is a component of a triple antibiotic ointment used for superficial skin infections.
74
Polymyxins Adverse Effects
Nephrotoxicity, neurotoxicity (eg, slurred speech, weakness, paresthesias), respiratory failure.
75
Sulfonamide Mechanism
Inhibit dihydropteroate synthase, thus inhibiting folate synthesis. Bacteriostatic (bactericidal when combined with trimethoprim).
76
Sulfonamide Clinical Use
Gram ⊕, gram ⊝, Nocardia. TMP-SMX for | simple UTI
77
Sulfonamide Adverse Effects
Hypersensitivity reactions, hemolysis if G6PD deficient, nephrotoxicity (tubulointerstitial nephritis), photosensitivity, Stevens-Johnson syndrome, kernicterus in infants, displace other drugs from albumin (eg, warfarin)
78
Sulfonamide Mechanism of Resistance
``` Altered enzyme (bacterial dihydropteroate synthase),  uptake, or  PABA synthesis. ```
79
Sulfonamide Examples
Sulfamethoxazole (SMX), sulfisoxazole, | sulfadiazine
80
Trimethoprim Mechanism
Inhibits bacterial dihydrofolate reductase. | Bacteriostatic
81
Trimethoprim Clinical Use
Used in combination with sulfonamides (trimethoprim-sulfamethoxazole [TMPSMX]), causing sequential block of folate synthesis. Combination used for UTIs, Shigella, Salmonella, Pneumocystis jirovecii pneumonia treatment and prophylaxis, toxoplasmosis prophylaxis.
82
Trimethoprim Adverse Effects
Hyperkalemia (high doses), megaloblastic anemia, leukopenia, granulocytopenia, which may be avoided with coadministration of leucovorin (folinic acid). TMP Treats Bone Marrow Poorly.
83
Fluroquinolones Examples
Ciprofloxacin, enoxacin, norfloxacin, ofloxacin; respiratory fluoroquinolones—gemifloxacin, levofloxacin, moxifloxacin.
84
Fluroquinolones Mechanism
Inhibit prokaryotic enzymes topoisomerase II (DNA gyrase) and topoisomerase IV. Bactericidal. Must not be taken with antacids
85
Fluroquinolones Clinical Use
Gram ⊝ rods of urinary and GI tracts (including Pseudomonas), some gram ⊕ organisms, otitis externa.
86
Fluroquinolones Adverse Effects
GI upset, superinfections, skin rashes, headache, dizziness. Less commonly, can cause leg cramps and myalgias. Contraindicated in pregnant women, nursing mothers, and children < 18 years old due to possible damage to cartilage. Some may prolong QT interval. May cause tendonitis or tendon rupture in people > 60 years old and in patients taking prednisone. Ciprofloxacin inhibits cytochrome P-450. Fluoroquinolones hurt attachments to your bones
87
Fluroquinolones Mechanism of Resistance
Chromosome-encoded mutation in DNA gyrase, plasmid-mediated resistance, efflux pumps
88
Daptomycin Mechanism
Lipopeptide that disrupts cell membranes of gram ⊕ cocci by creating transmembrane channels.
89
Daptomycin Clinical Use
S aureus skin infections (especially MRSA), bacteremia, endocarditis, VRE. Not used for pneumonia (avidly binds to and is inactivated by surfactant). “Daptomyskin” is used for skin infections
90
Daptomycin Adverse effects
Myopathy, rhabdomyolysis.
91
Metronidazole Mechanism
Forms toxic free radical metabolites in the bacterial cell that damage DNA. Bactericidal, antiprotozoal.
92
Metronidazole Clinical Use
Treats Giardia, Entamoeba, Trichomonas, Gardnerella vaginalis, Anaerobes (Bacteroides, C difficile). Can be used in place of amoxicillin in H pylori “triple therapy” in case of penicillin allergy. GET GAP on the Metro with metronidazole! Treats anaerobic infection below the diaphragm vs clindamycin (anaerobic infections above diaphragm)
93
Metronidazole Adverse Effects
Disulfiram-like reaction (severe flushing, tachycardia, hypotension) with alcohol; headache, metallic taste.

Antibiotics (1 decks)

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