Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

PHAR152 > Antibiotics > Flashcards

Antibiotics Flashcards

1
Q

What are the major antibiotic categories?

A

beta-lactams (penicillin, cephalosporins, carbapenens)
macrolides and clindamycin
tetracyclines/glycylcyclines
glycopeptides
aminoglycosides
quinolones
sulfonamides and trimethoprim
metronidazole
linezolid

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

How do penicillin’s exhibit their action?

A

bind to penicillin binding protein (PBP) resulting in inhibition of peptidoglycan synthesis and activation of autolytic enzymes in cell wall

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

True or false: penicillins are bacteriostatic

A

false
they are bactericidal

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

How does resistance develop to penicillins?

A

production of beta-lactamases
lack of PBP or altered PBP
efflux of drug out of cell
failure to synthesize peptidoglycans such as mycoplasmas or metabolically inactive bacteria

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

What is the structure of penicillins?

A

6-aminopenicillanic acid (thiazolidine ring attached to beta-lactam ring)

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

What are the natural penicillins?

A

penicillin G
penicillin V

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

Which bacteria is penicillin G highly active against?

A

gram positive and spirochetes

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

Describe penicillin G.

A

highly active against gram + and spirochetes
destroyed by beta-lactamases
acid labile (not used orally)

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

What are the available forms of penicillin G?

A

aqueous Pen G
procaine Pen G (IM)
benzathine Pen G (IM)

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

What is the difference between penicillin G and penicillin V?

A

penicillin V is an oral formulation that is more acid stable

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

What are the special instructions for use of penicillin V?

A

taken on an empty stomach

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

What are the uses of the natural penicillins?

A

DOC for:
-streptococci
-pneumococci
-meningcocci
-spirochetes
-clostridia
-anaerobic gp rods
-actinomyces
-enterococci

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

Which penicillins are designed for Staph aureus?

A

cloxacillin
methicillin
flucloxacillin
dicloxacillin

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

What are the “anti-staphylococcal” penicillins relatively resistant to?

A

beta-lactmases

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

When should the pencillins such as cloxacillin or methicillin not be used?

A

should not be used for MRSA
-methicillin resistant staph aureus

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

What is the spectrum of activity for aminopenicillins?

A

active against both gp and gn
-streptococci, enterococci, neiserria, non-blp H influenzae, e.
coli, p. mirabilis, salmonella, etc

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

What can destroy the aminopenicillins?

A

beta-lactamases

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

What are the aminopenicillins? Describe each.

A

ampicillin
-IV
-more acid stable than the natural pencillins
-poor bioavailability
amoxicillin
-oral
-better absorption than ampicillin
-can be combined with clavulanic acid

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

What is clavulanic acid?

A

beta-lactamase inhibitor

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

What does beta-lactamase do?

A

opens the beta-lactam ring of penicillins and cephalosporins
no longer active

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

What are ESBLs?

A

extended spectrum beta-lactamases
-found in E.coli and Klebsiella pneumoniae

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

What is NDM BL?

A

New Delhi metallo-beta-lactamase
-found in Acteinobacter baumannii

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

What is the ureidopenicillin presented in class?

A

piperacillin

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

Which penicillin has increased activity against Pseudomonas aeruginosa?

A

piperacillin (great against gn rods)
-parenteral only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Which drug is piperacillin availably combined with?
tazobactam (beta-lactamase inhibitor)
26
Describe the pharmacokinetics of penicillins.
oral bioavailability varies wide tissue distribution including CNS most are excreted by the kidneys short half-life concentration independent PD all taken on empty stomach but one safe in pregnancy distributed to breast milk
27
Which pencillin should be taken with food?
amoxicillin
28
Why are penicillins frequently dosed?
short half-lifes
29
What is a drug interaction that must be kept in mind with penicillins?
oral contraceptives -penicillins can destroy the estrogen -explain it to the woman
30
What are the adverse effects of penicillins?
allergic reactions anaphylactic shock serum sickness (fever, joint stiffness, rash) skin rashes fever, nephritis, eosinophilia electrolyte imbalance neutropenia, thrombocytopenia diarrhea, GI upset (most common)
31
What is the structure of cephalosporins?
7-aminocephalosporanic acid
32
Why are cephamycins not considered to be a true cephalosporin?
they have an oxygen where the sulfur is
33
What is the MOA of cephalosporins?
same as penicillins (PBP to decrease peptidoglycan synthesis) bactericidal
34
In terms of resistance, how do cephalosporins differ from penicillins?
cephalosporins are resistant to beta-lactamases produced by Staph aureus and common gnb (increased spectrum)
35
How does resistance develop to cephalosporins?
lack of PBP or altered PBP beta-lactamase efflux inability to penetrate
36
What are the first generation cephalosporins?
oral: cephalexin and cefadroxil IV/IM: cefazolin
37
What is the activity of first generation cephalosporins?
gram positive cocci, NOT enterococci or MRSA some gram negative bacilli (E.coli, Proteus, Klebsiella)
38
True or false: first generation cephalosporins penetrate the CNS
false
39
What situations are first generation cephalosporins the DOC?
not the DOC for any infection except cefazolin for surgical prophylaxis
40
What are the second generation cephalosporins?
oral: cefuroxime axetil, cefprozil IV/IM: cefuroxime
41
What is the activity of second generation cephalosporins?
organisms covered by 1st gen cephalosporins greater coverage of gram negative bacilli (not Pseudomonas aeruginosa)
42
What are the third generation cephalosporins?
cefotaxime, ceftriaxone, ceftadizime (IV) cefixime (oral)
43
What is ceftadizime reserved for?
Ps. aeruginosa
44
What is the activity of third generation antibiotics?
decreased activity against gram positive cocci (except Strep pneumoniae) enhanced activity against gram negative bacilli
45
What is the difference in tissue distribution between 1st gen and 3rd gen cephalosporins?
3rd gen can penetrate the CNS
46
What are the fourth generation cephalosporins?
cefepime (enterobacter and citrobacter, Ps. aeruginosa) ceftaroline and ceftobiprole (MRSA, ampicillin sensitvive E. faecalis, penicillin resistant S. pneumoniae)
47
What are the adverse effects of cephalosporins?
hypersensitivity diarrhea and skin rash=most common other: fever, granulocytopenia, hemolytic anemia
48
What is a unique side effect of ceftriaxone?
biliary pseudolithiasis
49
What are the carbapenems?
imipenem meropenem ertapenem
50
What is imipenem always given with?
cilastatin -protects from dehydropeptidase and prolongs antibacterial effects
51
What is the activity of imipenem and meropenem?
gram positive gram negative (including Pseudomonas) anaerobic organisms
52
What is the activity of ertapenem?
poor activity against enterococcus and P. aeruginosa
53
Which carbapenem is given once daily?
ertapenem (long half-life)
54
Describe monobactams.
monocyclic beta-lactam ring resistant to beta-lactamases active against gnb including P. aeruginosa not active against ESBL or AmpC producers
55
What is a monobactam discussed in class, not available in Canada?
aztreonam
56
What are the macrolides?
erythromycin clarithromycin azithromycin
57
What is the MOA of macrolides?
attach to the 23S rRNA on the 50S subunit of bacterial ribosome resulting in inhibition of protein synthesis bacteriostatic; time dependent killing (conc independent)
58
How does resistance develop to macrolides?
methylation of the rRNA receptor inactivating enzymes efflux
59
What is the spectrum of activity of macrolides?
gram positive: pneumococci, streptococci, corynbacteria M pneumoniae Chlamydia trachomatis C. pneumophilia Bordatella pertussis Campylobacter jejuni Helicobacter pylori
60
What are the available forms of erythromycin?
base stearate (succinate) estolate
61
Why is erythromycin avoided IV?
can cause severe phlebitis
62
What are the adverse effects of erythromycin?
GI (macrolides known to have significant GI effects) increased liver function tests (LFTs) cholestatic hepatitis (increased with estolate and pregnancy) QT prolongation/cardiac arrhythmias (especially with CYP 3A inhibitors)
63
What is the activity of clarithromycin and azithromycin?
active against staph and strep useful for some MRSA enhanced activity against variety of organisms
64
If an organisms is resistant to erythromycin, then which other drugs would we suspect this organism to be resistant to?
clarithromycin and azithromycin
65
How do clarithromycin and azithromycin compare to erythromycin in dosing and adverse effects?
less frequent dosing lower rate of GI effects
66
What is the concern with a 5 day therapy of azithromycin?
azithromycin has long half-life 5 days of azithromycin=10 days of therapy may lead to more resistance
67
What are the uses of the macrolides?
URTIs STIs acne
68
What are the drug interactions for macrolides?
erythromycin and clarithromycin are substrates+inhibitors of CYP 3A4, so many drugs that are metabolized by CYP 3A4 antiarrythmias antidepressants anticonvulsants statins *fewer with azithromycin*
69
What is the MOA of clindamycin?
same as macrolides -has different structure
70
When is clindamycin the DOC?
never
71
What is the spectrum of clindamycin?
anaerobes S.aureus some MRSA streptococci
72
When is clindamycin typically used?
penicillin allergy resistant organism
73
What are the adverse effects of clindamycin?
nausea, vomitting, diarrhea rash elevated LFTs esophageal irritation ASSOCIATED WITH C. DIFFICILE DIARRHEA
74
What are the tetracyclines?
tetracycline minocycline doxycycline
75
What is the MOA of tetracyclines?
inhibit binding of aminoacyl-tRNA to the 30S unit of ribosome therby inhibiting protein synthesis bacteriostatic
76
What is the spectrum of activity of tetracyclines?
many gp and gp -high rates of resistance
77
When are tetracyclines the DOC?
rickettsiae bartonella chlamydia M. pneumoniae
78
What are the adverse effects of tetracyclines?
GI upset skin rashes photosensitivity yeast overgrowth deposited in bones and teeth hepatitis vestibular toxicity (dizziness, vertigo, ataxia)
79
Which group are tetracyclines contraindicated in?
children <8
80
Which tetracycline is associated with hypersensitivity reactions?
minocycline
81
What are some drug interactions with tetracyclines?
some anticonvulsants divalent and trivalent cations reduce absorption -iron, bismuth, calcium, magnesium, aluminum increased INR and bleeding with warfarin
82
What are the synthetic analogues of tetracyclines?
glycylcyclines: -tigecycline
83
What is the spectrum of activity of glycylcyclines?
many gp and gn -MRSA -S. pneumoniae -enterococci -salmonella -shigella -actinobacter -anaerobes
84
How are glycylcyclines eliminated?
biliary tract or feces
85
What is the reserved usage of glycylcyclines?
resistant organisms
86
What is the glycopeptides studied in class?
vancomycin
87
What is the MOA of glycopeptides?
inhibits cell wall peptidoglycan synthesis bactericidal
88
Which organisms are resistant to vancomycin?
VRE S. aureus
89
What is the spectrum of activity of vancomycin?
gpc in particular enterococci PRSP MRSA clostridia some bacilli
90
When is vancomycin given orally? What about IV?
orally: C. difficile only (not orally absorbed) IV for serious infection
91
What are the adverse reactions of vancomycin?
nephrotoxicity (especially in combo with nephrotoxins) ototoxicity (hearing impairment, messes with balance) red-man syndrome granulocytopenia
92
True or false: therapeutic drug monitoring is not commonly performed with vancomycin
false commonly performed
93
What are the aminoglycosides?
streptomycin gentamicin tobramycin amikacin
94
What is the MOA of aminoglycosides?
inhibit protein synthesis by inhibiting 30S subunit of bacterial ribosome
95
How does resistance develop to aminoglycosides?
mutation or methylation of 16S rRNA-binding site enzymatic destruction of drug lack of permeability to the drug molecule active efflux
96
What is the spectrum of aminoglycosides?
aerobic gnb synergistic with penicillins for enterococci and streptococci streptomycin for TB
97
What is the route of administration for aminoglycosides?
IV/IM (not orally absorbed)
98
How good is the penetration of aminoglycosides? How are they eliminated?
poor tissue penetration, not CNS renal elimination
99
True or false: therapeutic drug monitoring is commonly performed with aminoglycosides
true
100
What are the adverse effects of aminoglycosides?
nephrotoxicity ototoxicity neuromuscular blockade allergies rare
101
What are the fluoroquinolones?
ciprofloxacin levofloxacin moxifloxacin
102
What is the MOA of fluoroquinolones?
inhibit DNA gyrase or topoisomerase II & IV bacteriocidal
103
How does resistance develop to fluoroquinolones?
alteration of the A or B subunit of DNA gyrase mutation in ParC or ParE of topoisomerase IV change in outer membrane permeability efflux
104
What is the spectrum of fluoroquinolones?
highly active against gnb, haemophilus, neisseriae, chlamydiae ciprofloxacin-P.aeruginosa levofloxacin-S.pneumoniae moxifloxacin-anaerobes
105
What are the uses of fluoroquinolones?
UTIs STIs lower respiratory tract infections enteritis/travellers diarrhea drug resistant mycobacterial infections
106
Describe the pharmacokinetics of fluoroquinolones.
excellent oral bioavailability available IV or po but parenteral use not commonly needed ciprofloxacin and levofloxacin-renal elimination moxifloxacin-biliary pathway
107
What are the adverse effects of fluoroquinolones?
nausea, vomiting, diarrhea insomnia, headache, dizziness other CNS effects including seizures skin rashes impaired liver function tendinitis/tendon rupture prolongation of QTc interval hypo/hyperglycemia C. difficile peripheral neuropathy
108
What are the drug interactions associated with fluoroquinolones?
di and trivalent cations QTc prolongation CYP 1A2 inhibitors increased INR with warfarin
109
What are the reserved situations for fluoroquinolones?
resistant organisms or when you cant use the DOC not used in children <18
110
What is the MOA of sulfamethoxazole?
structural analogue of PABA; competitively inhibits dihydrofolate acid synthesis
111
What is the MOA of trimethoprim?
binds to dihydrofolate reductase therefore inhibiting the reduction of dihydrofolic acid to tetrahydrofolic acid
112
How does resistance develop to SMX and TMP?
ability of cell to use preformed folic acid
113
What is the spectrum of SMX and TMP?
wide spectrum of gp, gn, chlamydiae, nocardiae, protozoa staphylococci-including MRSA S. pneumoniae (not group A strep) S. maltophilia moraxella H. influenza enterobacteriaciae brucella pneumocystis jirovecii
114
What are the uses of SMX and TMP?
UTIs skin and soft tissue infections-MRSA PJP many others
115
What are the adverse effects of sulfonamides and trimethoprim?
skin rashes (can be severe) hypersensitivity headache GI bone marrow suppression hyperkalemia & hyponatremia photosensitivity
116
What is CI of SMX/TMP? What is a caution with SMX/TMP?
CI: first and third trimester of pregnancy caution: renal dysfunction
117
What is the MOA of metronidazole?
unknown but possible inhibition of nucleic acid synthesis and disruption of DNA
118
What is the spectrum of metronidazole?
anaerobes including C.difficile protozoa-trichomonas, giardia
119
Which organism is resistant to metronidazole?
propionibacterium
120
What are the adverse effects of metronidazole?
GI metallic taste headache dark urine peripheral neuropathy disulfiram-like reaction with alcohol insomnia stomatitis
121
What are the drug interactions of metronidazole?
alcohol increased INR and bleeding with warfarin
122
What is the MOA of linezolid?
inhibits protein synthesis usually bacteriostatic bactericidal against Streptococci
123
What is the spectrum of linezolid?
streptococci enterococci (including VRE) staphylococci (including MRSA)
124
What is the reserved use of linezolid?
multi-drug resistant organisms an alternative to vancomycin
125
What are the adverse effects of linezolid?
headache nausea, vomiting, diarrhea rash increased LFTs myelosuppression optic/peripheral neuropathy lactic acidosis decreased seizure threshold
126
What are the drug interactions for linezolid?
increased serotonin syndrome risk with SSRIs and MAOs rifampin decreases linezolid levels

PHAR152 (21 decks)

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