Antibiotics - notes Flashcards
1
Q
What are the different antibiotic classes that are cell wall inhibitors?
A
- Beta-lactams
- lipoglycoproteins
- vancomycin
2
Q
What are the different drugs included in beta-lactams?
A
- penicillin
- cephalosporins
- monobactams
- carbapenems
- beta-lactamase inhibitor compounds
3
Q
- What are the drugs in the natural penicillin group?
- What are their routes of administration?
- What is their spectrum/coverage?
- do they cover gram + or gram -?
A
penicillin G
- IV/IM
- narrow spectrum
- gram +
penicillin V
- oral (more stable)
- narrow spectrum
- gram +
4
Q
- What is the drug of choice for syphilis?
- What is the drug of choice for GABHS rheumatic fever?
A
- penicillin G
- penicillin V
5
Q
Are natural penicillins sensitive to beta-lactamase?
A
yes
6
Q
What are some general uses of natural penicillins?
A
- staph pharyngitis
- soft tissue infections caused by strep A
- some mouth/GI anaerobes (peptococcus/peptostreptococcus)
- meningitis due to N. meningitides, S. pneumo, Listeria
7
Q
What are the drugs in the antistaphylococcal penicillins?
A
- dicloxacillin
- methicillin
- oxacillin
- nafcillin
8
Q
- What is the spectrum of dicloxacillin?
- Does it cover gram +/gram -?
- What is its resistance to beta-lactamase?
- Is there aerobic coverage?
- What do you use dicloxacillin to treat?
A
- narrow spectrum
- gram +
- beta-lactamase resistant
- no aerobic coverage
- MSSA
9
Q
- What antistaphylococcal penicillin won’t be used to treatment, only testing purposes?
- What are the side effects of nafcillin?
A
- methicillin
- nephritis, neutropenia
10
Q
What drugs are included in the aminopenicillins?
A
- amoxicillin
- ampicillin
11
Q
- What is the spectrum of aminopenicillins?
- Do they cover gram+ or gram -?
- What is their resistance to beta-lactamase?
- What are they used to treat?
A
- broader spectrum
- good gram +, some gram -
- beta-lactamase sensitive
- H. flu, E. coli
12
Q
What is the drug of choice for Listeria monocytogenes (meningitis)? How is this drug given for this treatment?
A
ampicillin - IV
13
Q
What can you use amoxicillin to treat?
A
- empirical treatment of sinusitis, otitis media (strep)
- premed for endocarditis prophylaxis during dental/invasive procedures
14
Q
- What can you add to aminopenicillins to allow for treatment of MSSA?
- What are inhibitor combinations for amoxicillin and ampicillin?
A
- beta-lactamase inhibitors
combinations: - ampicillin/sulbactam
- amoxicillin/clavulanic acid
15
Q
What are the drugs in the antipseudomonal penicillins?
A
- piperacillin
- carbenicillin
- ticarcillin
16
Q
- What is the spectrum of piperacillin?
- What does this drug cover, gram +/-?
- What is its resistance to beta-lactamase?
- What is its route of administration?
- What is this drug used to treat?
A
- broad spectrum
- good gram +, improved gram -
- beta-lactamase sensitive
- IV only
- Pseudomonas aeruginosa, polymicrobial, and nosocomial infections
17
Q
What is piperacillin used to treat?
A
- pseudomonas aeruginosa
- polymicrobial infections
- nosocomial infections
18
Q
- What are antipseudomonal penicillins effective in treating with the addition of beta-lactamase inhibitors?
- Why would we not use this?
- Which antipseudomonal penicillin is the most potent?
- Antipseudomonal penicillins provide less coverage to what than ampicillin?
A
- MSSA
- there are other drugs that can treat MSSA; we don’t want to build resistance
- piperacillin
- less staph and strep coverage
19
Q
What are the different types of side effects/reactions to penicillins?
A
- type I: immediate response (anaphylactic shock)
- type II: penicillin-associated hemolytic anemia (autoimmune)
- type III: delayed response (skin rash, glomerular nephritis, polyarthritis, pericarditis/pleuritic, lymphadenopathy, angioedema)
20
Q
- What percentage of patients allergic to penicillins will be allergic to cephalosporins?
- What is it okay to give cephalosporins in pts allergic to PCN?
A
- 10%
- okay to give to pts with type II or III reactions
21
Q
What are other side effects of penicillins?
A
- ampicillin-associated maculopapular rash
- diarrhea (poor absorption)
- nephritis
- neurotoxicity w/ high doses given intrathecally; seizures
- hematologic toxicity (piperacillin)
- cation toxicity (hypokalemia/hyponatremia)
22
Q
What side effect does piperacillin cause?
A
hematologic toxicity
23
Q
What is the MOA of penicillins?
A
- bactericidal
- contain beta-lactam ring that interacts with PBP
- inhibits transpeptidase (prevents cross-linking of peptidoglycan=weak cell wall)
- binds autolysin inhibitors = increases autolysin activity = breakdown of cell wall
- requires actively proliferating bacteria
24
Q
What drugs treat MRSA?
A
- sulfamethoxazole/TMP
- clindamycin
- fluoroquinolones
- vancomycin
- daptomycin
- linezolid
25
What drugs are in the first generation of cephalosporins? What are their routes of administration?
- **cephalexin-po**
- cefadroxil-po
- cefazolin-IV
26
What is the coverage of cephalexin?
- good gram + (MSSA, staph, strep)
- limited gram - (PEcK)
**P. mirabilis, E. coli, K. pneumo
- not good anaerobic coverage (no B. fragilis)
27
What is the resistance to beta-lactamase of cephalexin?
not sensitive to beta-lactamase
28
What are the general uses of first generation cephalosporins?
- skin/soft tissue infections (not bites)
- URI
- cefazolin (surgical prophylaxis for orthoped surgeries d/t **good bone penetration**)
- oral routes = not for serious infections
29
If a patient has type I reactions to PCN and is in need for treatment for MSSA, what antibiotic can you give them?
cephalexin
30
- How is cephalexin excreted?
- What is the cross-reactivity it has to PCN allergy?
- renally eliminated
- 10% cross-reactivity
31
What are the drugs in the second generation cephalosporins? What are their routes of administration?
- cefuroxime-po/IV
- cefprozil-po
- cefaclor-po
- cefoxitin-IV
- cefotetan-IV
32
What is the coverage of second generation cephalosporins?
- same as 1st generation coverage
- more gram - (HENPEcK)
** H. flu
** Enterobacter
** Neisseria
** P. mirabilis
** E. coli
** K. pneumo
- anaerobic coverage of **B. fragilis** w/ cefoxitin, cefotetan
33
What are some general uses of second generation cephalosporins?
- CAP
- otitis media
- respiratory infections
- sinusitis
- skin/soft tissue infections
- MSSA
- cefuroxime not good with gut anaerobes
- cefoxitin, cefotetan good gut/pelvic coverage
34
What are some of the drugs included in the third generation cephalosporins? What are their routes of administration?
- **cefdinir-po**
- **ceftriaxone-IV/IM**
35
What is the coverage of third generation cephalosporins?
- vary in gram +
- great gram -
**Serratia marcescens, no enterobacter
**ceftazidime covers. P. aeruginosa
36
What are the characteristics of ceftriaxone?
- third generation cephalosporin
- longest half-life of all cephalosporins
- excreted in bile (good for pts w/renal failure)
- good bone pentration
- commonly used in gonorrhea treatment
- effective in HACEK endocarditis
37
Which cephalosporin is commonly used in gonorrhea treatment?
ceftriaxone
38
What are the general uses of third generation cephalosporins?
- bacterial meningitis
- HAP
- Lyme disease
- ceftriaxone/cefotaxime: meningitis from pneumococci, H. flu, meningococci; no L. monocytogenes; empiric tx in serious infections, sepsis
39
Third generation cephalosporins have what type of resistance to beta-lactamase?
they are sensitive to beta-lactamases
40
- What type of infections are you going to use third generation cephalosporins?
- What type of spectrum does cefdinir have?
- What can you use cefdinir to treat?
- What can IV preps of third generation cephalosporins cross?
- serious infections
- broader spectrum
- otitis media, CAP, sinusitis
- BBB
41
What drug is a fourth generation cephalosporin? What is its route of administration?
- cefepime-IV
42
What is the coverage of cefepime?
- good gram + (MSSA)
- good gram - (enterobacter, p. aeruginosa)
43
What can you use cefepime to treat?
- p. aeruginosa infections
- only ceph for enterobacter and serratia
- meningitis
- CAP
44
What is the sensitivity of cefepime to beta-lactamase?
used to be resistance but is now becoming more sensitive
45
What drug name is the fifth generation cephalosporin? What is its route of administration?
- ceftarolene-IV
46
What is the coverage of ceftarolene?
- enhanced gram + (MSSA, S. pneumo, E. faecilis)
- gram -
- no pseudomonas
- poor anaerobic coverage
47
What can you use ceftarolene to treat?
- MSSA
- skin/soft tissue infections
- CAP
48
What are the side effects of cephalosporins?
- hypersensitivity
- 10% cross-reactivity with PCN (occurs in 1st gen more often) = don't use w/ pts who have had anaphylactic rxns to PCN
49
What is the MOA of cephalosporins?
- binds to PBP and autolysin inhibitors
- interrupts cell wall synthesis and activate autolysins
- bactericidal
50
- Where are cephalosporins distributed?
- How are they excreted?
- body fluids, CSF, bone
- renally excreted except for ceftriaxone which is excreted in bile
51
- What are the cephalosporin + inhibitor combinations?
- What do they cover?
- What are they FDA approved to treat?
**inhibitor combo**
- ceftolozone/tazobactam
- ceftazidime/avibactam
**coverage**
- excellent gram -
- P. aeruginosa
**FDA approval**
- complicated intra-abdominal infections along with anaerobic infections
- complicated UTI
- HAP and VAP
52
- What drug is a monobactam?
- What is its route of administration?
- What is its coverage?
- aztreonam
- IV/IM
- limited gram - (covers P. aeruginosa)
- no gram + or anaerobic infections
53
What are the side effects of aztreonam?
- no cross rxn with PCN
- same allergies as PCN
54
What can you use aztreonam to treat?
pseudomonas treatment especially in cases where pt is allergic to PCN (type I rxn)
55
What are the drugs included in carbapenems? What are their routes of administration?
- **imipenem/cilastin-IV/IM**
- doripenem
- ertopenem
- meropenem
56
What is the coverage of carbapenems?
- gram +
- gram - (P. aeruginosa)
- anaerobes
57
What can you use carbapenems to treat?
- pseudomonas infections when organism is resistant to other drugs
- mixed infections
- very effective in **enterobacter** infections
58
What can you use to treat enterobacter infections due to them being very effective in treating these?
carbapenems (imipenem/cilastin)
59
What are the adverse reactions of carbapenems?
- N/V/D
- rash
- 1% cross reactivity with PCN
- imipenem: seizures, mental status changes
60
What are the adverse reactions of imipenem/cilastin?
- seizures
- mental status changes
61
- How are carbapenems excreted?
- Why do you need to give cilastin with imipenem?
- When would you use carbapenems?
- renally excreted
- imipenem is inactivated in renal tubules; cilastin inhibits dehydropeptidase which stops imipenem from being broken down
- would use them if pts culture came back pseudomonas resistant to other drugs (last resort due to severe side effects)
62
What drug is a glycopeptide antibiotic?
vancomycin
63
What is the MOA of vancomycin?
- inhibits glycosylation of NAM-NAG units
- doesn't rely on transpeptidase
- bactericidal
64
What is the coverage of vancomycin?
best for gram + (MRSA, MRSE, enterococci, clostridium)
65
What are the clinical uses of vancomycin?
- MRSA sepsis, endocarditis
- vanco + gentamicin = enterococcal endocarditis where pt is allergic to PCN
- in combo with cephs = meningitis
- C. diff via oral route
66
What type of vancomycin would you use to treat C. diff?
oral vancomycin
67
What are the adverse effects of vancomycin?
- red man syndrome (given too rapidly)
- phlebitis
- ototoxicity/nephrotoxicity if given with other toxic drugs like aminoglycosides
68
What is the distribution of vancomycin?
- CSF and adipose tissue
- dose adjust in renal impairment:
**normal half-life: 6-10 hours
**renal disease half-life: 200 hours
69
- What should you think of treating when using vancomycin?
- What is vancomycin often given with?
- What is the toxicity of this drug?
- MRSA
- gentamicin
- very toxic
70
What drugs are protein synthesis inhibitors?
- aminoglycosides
- tetracyclines
- macrolides
- clindamycin
- chloramphenicol
- linezolid
71
What drug in included in aminoglycosides we need to know?
gentamicin
72
What is the coverage of aminoglycosides?
- used w/ beta-lactams in serious gram - (vanco), gram + (endocarditis), and TB
- no anaerobic coverage
73
What is the MOA of aminoglycosides?
- passes through porin channels
- uses oxygen dependent active transport
- enhanced by other cell wall inhibitors
- binds 30S subunit of ribosome irreversibly
- bactericidal
74
What are the indications of aminoglycosides?
- aerobic gram + (steph/strep with beta-lactams)
- aerobic gram - (klebsiella, E. coli, proteus with beta-lactams; pseudomonas with antipseudomonals; brucella, taluremia, plague with tetracyclines)
- severe gram - infections in combo
- group B strep in neonates
- intrathecal for gram - meningitis
75
What is treated when you combine aminoglycosides with tetracyclines?
- brucella
- taluremia
- plague
76
What is the distribution of gentamicin?
- poor oral absorption
- not metabolized
- distributes poorly to CSF/lungs (low Vd)
- pregnancy category C/D = don't use in lactation
77
What are the adverse affects of gentamicin?
- nephrotoxicity
- ototoxicity; can cause permanent deafness
78
- What is the route of administration of aminoglycosides?
- Will you use them by themselves in systemic infections?
- What is an example of this?
- IV, IM, intrathecally, intraventricular, topical
- no
- using vanco for gram +, gentamicin for gram -, so they can be used together in serious infections
79
What drugs are included in the tetracyclines?
- **tetracycline**
- **doxycycline**
- **minocycline**
- demecycline
80
What is the MOA of tetracyclines?
- bacteriostatic
- enter bacteria through passive diffusion and active transport
- binds reversibly to 30S subunit of bacterial ribosome; inhibits protein synthesis
81
What is the coverage of tetracyclines?
- broad spectrum
- gram + and gram -
82
What would you use tetracyclines for?
- acne
- peptic ulcers
- infections from animals (Lyme disease, Rocky mountain spotted fever)
83
What are the resistance mechanisms of tetracyclines?
- efflux pump (doxy and mino poor substrates for pump)
- production of proteins that prevent tetracyclines from binding to ribosomes
- enzymatic destruction
84
What impairs the absorption of tetracyclines?
food up to 50%
- food has less effect on doxy, mino
- binds to divalent cations (Ca, Mg, aluminum)
85
What is the distribution of tetracyclines?
- poor CSF penetration
- crosses placental barrier and is excreted in breast milk (not recommended in pregnancy)
- not metabolized
86
How are tetracyclines excreted?
in bile and urine (enterohepatic reabsorptions = don't have to dose as much because it is reabsorbed into the system)
87
Which tetracycline is non-renal?
doxycycline
88
What pregnancy category are tetracyclines?
category D
89
What are the adverse affects of tetracyclines?
- damage to growing bones/teeth = discoloration
- sun sensitivity
- one of the only drugs that is dangerous when expired = renal injury
90
- What should you not take with tetracyclines?
- Because they're excreted in bile, who can you use these drugs with?
- Ca, Mg, Aluminum, cottage cheese, yogurt
- pts with renal disease
91
What drugs are included in macrolides?
- **erythromycin**
- **azithromycin**
- clarithromycin
92
What is the MOA of macrolides?
- enters cell through passive/active diffusion
- binds irreversibly to 50S subunit of ribosome
- bacteriostatic
93
What is the coverage of macrolides?
- good gram +
- descent gram -
- **gained atypical coverage** (Legionella, Mycoplasma, Mycobacterium, Chlamydia)
94
Because atypical bugs don't have a peptidoglycan layer, what antibiotics can't you use?
beta-lactams
95
What is the drug of choice for chlamydia?
azithromycin
96
What are uses of macrolides?
- upper and lower respiratory infections including pneumonias
- pertussis
- peptic ulcer disease
- gut infections
97
What are resistance mechanisms of macrolides?
**plasma encoded**
- decreased permeability of cell membrane/efflux pump
- enterobacteriaceae esterase production = macrolide hydrolysis
- change in ribosomal binding site
**cross-resistance among macrolides**
- not first-line in pharyngitis, soft tissue infections, non-typical pneumo
98
- Which macrolide is poorly absorbed?
- Which macrolide is best on an empty stomach?
- Which macrolide diffuses into prostatic fluid?
- Where do macrolides concentrate?
- Tissue penetration is good for all macrolides except which one?
- erythromycin
- azithromycin
- erythromycin
- liver
- erythromycin
99
- Which macrolide has the largest Vd?
- Which macrolides are cytochrome inhibitors?
- Which macrolide does not affect cytochromes?
- How are macrolides excreted?
- azithromycin
- erythromycin, clarithromycin
- azithromycin
- in liver and renally
100
What is the drug of choice for diptheria?
erythromycin
101
What can be combined with neomycin for gut sterilization?
erythromycin
102
What can erythromycin be used to treat but other drugs are better tolerated?
CAP
103
Because erythromycin has similar coverage, what can this be an alternative for?
PCN
104
What can you use azithromycin to treat?
- prophylaxis of MAC
- better H. flu
- fantastic chlamydia treatment
- CAP
105
What are the adverse effects of macrolides?
- N/V/D (most common)
- QT prolongation and arrhythmias so don't use w/ pts who have pre-existing arrhythmias
106
What are adverse effects of erythromycin?
- cholestatic hepatitis (hypersensitivity)
- stimulate gut motility (hard on stomach)
- inhibits cytochromes (drug interactions)
107
What are adverse effects of azithromycin?
no concern of cytochrome issues seen with clarithromycin and erythromycin
108
- What should you always use for gut sterilization/gut surgery?
- If CAP is suspected to be caused by an atypical bug, what should you use?
- People with motility issues (such as from spinal cord injury), what might be good to use to help with gut motility?
- erythromycin + neomycin
- azithromycin
- erythromycin
109
What is the MOA of clindamycin?
- same as erythomycin
- penetrates tissues/abscesses well (no BBB penetration)
- may be static or cidal
110
What is most likely to cause a C. diff infection due it sitting in the gut and killing everything off?
clindamycin
111
What is the coverage of clindamycin?
- gram +
- anaerobes
112
What main things can you used clindamycin to treat?
- skin/soft tissue infections
- elimination of carrier state in strep
- premed for endocarditis prophylaxis if can't use PCN
- topically for acne/vaginal infections
113
What other things can you use clindamycin to treat?
- intra-abdominal infections
- pelvic infections
- osteomyelitis
- diabetic foot ulcers
- aspiration pneumonia
- dental infections
114
What is the MOA of choramphenicol?
- binds 50S ribosomal subunit reversibly
- inhibits peptidyl transferase, preventing protein chain elongation
- mostly static
115
What is the coverage of chloramphenicol?
- broad spectrum:
- can be given IV or po
116
What will you use chloramphenicol to treat?
- primarily in rickettsial infections or bacterial meningitis where there's no other option
- meningitis
- plague
- cholera
- typhoid fever
117
What are the primary illnesses treated with chloramphenicol?
- meningitis
- plague
- typhoid fever
- cholera
118
What are the adverse side effects of chloramphenicol?
- highly toxic (limited to life-threatening illnesses)
- fatal blood dyscrasias (aplastic anemia, thrombocytopenia)
- liver toxicity
- gray baby syndrome (neonates can't glucuronidate well; vomiting, limp, gray skin, cyanosis, hypotension, cardiovascular collapse)
119
What symptoms are associated with gray baby syndrome?
- vomiting
- limp
- gray skin
- cyanosis
- hypotension
- cardiovascular collapse
120
- Chloramphenicol is toxic to humans because (...)
- If this is on a culture and sensitivity and there are other options, what should you use?
- it interrupts the 50S subunit in humans as well
- use other options; reserve this for very sick patients
121
What is the MOA of linezolid?
- binds to 50S subunit at unique site
- no cross-resistance w/ other drugs
- inhibits bacterial initiation of mRNA translation
- mostly bacteriostatic
- 100% bioavailable in both IV and oral
122
What percent is linezolid bioavailable and in which routes of administration?
- 100%
- IV and orally
123
What is the coverage of linezolid?
- mostly gram +
**Corynebacterium, Listeria, Bacillis, Micrococcus
124
What is the distribution of linezolid?
- distributes well in perfused tissues
- no cytochrome interactions
125
What do you use linezolid in treating?
- MDR gram + infections
- HAP due to MRSA
- CAP due to S. pneumo and MSSA
- VRE infections
- skin/soft tissue infections
126
What are the adverse affects of linezolid?
- thrombocytopenia
- peripheral neuropathy
- optic neuropathy
- inhibits MAO (serotonin syndrome)
127
- What should you reserve linezolid for?
- Should you use this empirically?
- MDR, MRSA, and VRE infections where bugs are resistant to everything else
- no, don't use empirically
128
- What was the original formulation of quinolones?
- What was their coverage?
- How was their absorption and distribution?
- Were they cidal or static?
- nalidixic acid
- too narrow; some gram negative, no gram positive and no atypicals
- good oral absorption, poor distribution (stayed in the blood)
- bactericidal
129
- What is the formulation of fluoroquinolones?
- What were their improvements from quinolones?
- fluorinated analogs of nalidixic acid
- retains good oral bioavailability
- good distribution with deep tissue penetration
- affects intracellular organisms
- broad spectrum
130
- What type of potency do fluoroquinolones have?
- Are they cidal or static?
- How safe are they?
- very potent = very effective
- bactericidal
- very safe
131
- Fluoroquinolones gained coverage for what type of organisms that quinolones did not cover?
- What are the names of these organisms?
- atypical bacteria
- chlamydia, TB, legionella
132
- What is the MOA of 1st and 2nd fluoroquinolone generations?
- Describe the MOA
- What type of coverage do these have?
- inhibits topoisomerase II (DNA gyrase)
- DNA gyrase typically eases tenses on bacteria DNA coil to aide in replication by cutting/gluing parts of the chain; when it is inhibited, the cutting continues, but the gluing stops
- more active in gram negative
133
What is the MOA of 3rd and 4th fluoroquinolone generations?
- Describe the MOA
- What type of coverage do these have?
- inhibits topoisomerase IV
- topoisomerase IV usually takes progeny DNA, cuts it, glues it together, and then passes it along for replication; when inhibited, progeny DNA is destroyed and cannot be passed on to replicate (no more gluing)
- improved gram + activity
134
What are the resistance mechanisms to fluoroquinolones?
- efflux pump
- alteration of drug target
- porin alteration
- enzymatic deactivation of drug
*resistance to one means resistance to all*
135
- What is the drug name in the 1st generation fluoroquinolones?
- What is its coverage?
- When do you use these?
- nalidixic acid
- gram negative (narrow)
- uncomplicated UTIs
136
- What are the drug names in the 2nd generation fluoroquinolones?
- What is their coverage?
- **ciprofloxacin**, ofloxacin
- gram negative, some gram positive
- **gained atypical coverage**
137
What can 2nd generation fluoroquinolones be used to treat?
- Enterobacteriaceae
- **P. aeruginosa**
- anthrax
138
- What are the drug names in the 3rd generation fluoroquinolones?
- What is their coverage?
- **levofloxacin**
- gram negative, gram positive, and atypicals (S. pneumo, P. aeruginosa)
139
What can 3rd generation fluoroquinolones be used to treat?
- acute exacerbation of chronic pneumonia
- STD (not syphilis)
- prostatitis
- skin infections
- acute sinusitis
- CAP and HAP
140
- What are the drug names in the 4th generation fluoroquinolones?
- What is their coverage?
- **moxifloxacin**
- gram negative, gram positive, atypicals (S. pneumo, **anaerobes**)
141
What can 4th generation fluoroquinolones be used to treat?
- mixed infections
- **NO p. aeruginosa**
142
Out of all of the fluoroquinolones we need to know, which one cannot treat pseudomonas infections?
moxifloxacin
143
- How are fluoroquinolones absorbed?
- What do they bind to?
- How is their distribution?
- How are they eliminated?
- well absorbed orally
- divalent, trivalent cations and is bound by sucralfate and others
- good tissue penetration
- eliminated renally except for moxifloxacin which is excreted in bile
144
Fluoroquinolones can enter (...) cells to kill (...) bacteria
- host cells
- intracellular bacteria
145
Which fluoroquinolones have a long half-life so you only need to do daily dosing with these drugs?
- levofloxacin
- moxifloxacin
146
Which fluoroquinolone is excreted through bile?
moxifloxacin
147
- Which fluoroquinolone is most likely to cause QT prolongation? Which is least likely?
- What are 3rd and 4th generation fluoroquinolones used mostly for?
- Which one have the most gram negative treatment and can be used for travelers diarrhea?
- (most likely) moxi>levo>cipro (least likely)
- used mostly for respiratory infections
- ciprofloxacin
148
- What sulfonamide drug do we need to know?
- What is its route of administration?
- sulfamethoxazole/trimethoprim (SMX/TMP)
- oral/po
149
What is the MOA of sulfonamides?
- bacteriostatic/synergism
- inhibits production of folic acid; bacteria must make their own folic acid
150
- Sulfa antibiotics are structural analogs of PABA, so they inhibit what?
- They are combined with trimethoprim, which does what?
- dihydropterate synthetase/synthase
- dihydrofolate reductase inhibitor; stops additional step in folate production
151
What is the coverage of sulfonamides?
- some gram positive (good staph/strep)
- some gram negative (good H. flu)
**no anaerobes or atypicals**
152
Do sulfonamides cover anaerobes or atypical bacteria?
no
153
- How are sulfonamides absorbed?
- What is their distribution?
- How are they eliminated?
- What happens to them in the liver?
- orally absorbed; topically for burns
- good tissue penetration
- renally eliminated
- glucuronidated pr acetylated in the liver (need good liver function)
154
There is a resistance issue with sulfonamides, so (...) is rare
single agent use
155
What can sulfonamides be used to treat?
- MRSA
- PCP prophylaxis and treatment (good for HIV)
- E. coli and proteus predominant UTI
- gut infections due to enterobacteriacae
- bacterial respiratory infections
- acute otitis media
156
What are the adverse effects of sulfonamides?
- crystalluria (adequate hydration)
- hemolytic anemia (if G6PD deficient)
- kernicterus of newborn (bilirubin is displaced by sulfas)
157
What is safe in pregnancy but not at term and is not given to newborns?
sulfonamides
158
What does sulfonamide displace? What does this mean?
- warfarin
- methotrexate
- sulfonylureas
- phenytoin
**highly protein bound**
159
What cytochrome does sulfonamide inhibit?
CYP2C6
160
What do you have to keep in mind about sulfonamides (sensitivity)?
many strains are sensitive in vitro but not in vivo, limiting the utility of many sulfas
161
- Is nitrofurantoin cidal or static?
- What is its coverage?
- How is it metabolized?
- How is it excreted?
- What do you use nitrofurantoin for?
- What are the adverse effects?
- bactericidal
- gram positive, gram negative
- quickly metabolized (not good for systemic use)
- renally excreted
- only use for UTIs
- anorexia, hemolytic anemia (G6PD deficient), neuropathies, N/V common
162
- Because nitrofurantoin is renally excreted, it is contraindicated in which individuals?
- What organisms are not sensitive to nitrofurantoin?
- pts with CrCl < 60 mL/min
- P. aeruginosa and Proteus
163
What is the MOA of amphotericin B?
- only IV
- binds ergosterol fairly sensitive
- inserts itself in cell membrane forming pores that allow cellular contents to leak out
- fungistatic or fungicidal
164
Amphotericin B is not water soluble, so how is it given? Describe the structure of this antifungal?
- given in a suspension
- has a lipid and water loving side
165
- How many formulations of amphotericin B are there?
- Describe the newer formulations
- How does ampho B distribute?
- Is it highly protein bound or no?
- 4 available formulations
- newer formulations are less toxic, concentrate better in the liver, lung and spleen
- distributes and binds to tissues; but not good CSF penetration, vitreous humor, and amniotic fluid
- highly protein bound
166
- What does ampho B cross?
- What pregnancy category is this antifungal?
- crosses placenta
- category B
167
- What is the toxicity of ampho B?
- What are the types of toxicity side effects associated with this?
- What occurs in the first few weeks so you have to monitor electrolytes?
- very toxic, low TI
- infusion related toxicity; cumulative toxicity
- hypomagnesemia and hypokalemia
168
- Describe the side effects of infusion related toxicity with ampho B?
- How can you lessen these reactions?
- fever, chills, muscle spasms, vomiting, HA, hypotension
- test dosing, premedication, slow IV infusion, or decrease daily dosing
169
Describe the side effects of cumulative toxicity with ampho B?
- renal damage is nearly all pts (leading to dialysis)
- permanent renal damage due to cumulative dosing
170
What is the MOA of azole antifungals?
- inhibits fungal CYP450 enzyme needed to make ergosterol
- fungistatic
171
What drugs are azole antifungals?
- **fluconazole**
- **itraconazole**
- **voriconazole**
- ketoconazole
- posaconazole
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- What is the bioavailability of fluconazole?
- How is this drug available?
- What is its distribution?
- What is its metabolism?
- How is it excreted?
- What is its TI? What does this mean?
- good oral bioavailability (nearly 100%)
- oral and IV (GI acidity not a concern)
- penetrates CSF (cryptococcal meningitis)
- poor metabolism
- renally excreted
- large TI = very safe
173
What is fluconazole used for?
reserve for candida infections
174
What are the side effects of fluconazole?
- highly sensitive for fungal CYP450 (no endocrine side effects)
- lots of drug interactions than others, but not as severe
- not safe in pregnancy
175
What cytochromes does fluconazole inhibit?
- CYP2C19
- CYP2C9
- CYP3A4
176
- What does itraconazole require for absorption?
- What is its distribution?
- How is this bound to proteins?
- How is this antifungal metabolized?
- requires high acidity = drink a coke
- distributes well into bones but not CSF
- highly protein bound
- hepatically metabolized
177
Because itraconazole is hepatically metabolized, what should you do?
use cautiously in severe renal/hepatic insufficiency
178
What is itraconazole used for?
- candida
- aspergillus
- histoplasma
- onychomycosis (male fungal infections)
179
What are the less severe side effects associated with itraconazole?
- GI (most common)
- HA
- rash
- increases LFTs
180
What are the black box warnings associated with itraconazole?
- don't give with drugs that increase QT intervals or pts with arrhythmias
- negative inotropic effects so don't give to CHF pts
181
Itraconazole is a substate and potent inhibitor of what cytochrome? What does this mean?
- CYP3A4
- will have significant drug interactions
182
- What is the distribution of voriconazole?
- What versions are there?
- What is this a safer alternative for?
- penetrates tissues and CSF
- oral version (and IV) so it is safe to send pts home on this
- safer alternative for amphotericin B
183
What is voriconazole metabolized and and inhibits?
- CYP2C6
- CYP3A4
- CYP2C19
184
What is voriconazole used to treat?
- candida, aspergillus, fusarium, molds
- **replaces ampho B in tx of invasive aspergillus**
185
What are the side effects associated with voriconazole?
- visual/auditory disturbances
- hypertension/cardiac
- GI
- increased LFTs
- HA
- not safe in pregnancy
186
What are other antifungals that are not azole antifungals?
- terbinafine
- griseofulvin
187
What is the MOA of terbinafine?
- non-azole, allylamine antifungal
- inhibits fungal squalene epoxidase (interrupts cell wall synthesis)
- toxic amounts of squalene accumulate in fungi causing death
188
How is terbinafine available?
orally and topically
189
What can terbinafine be used for?
- dermatophytoses, especially onychomycoses due to lipophilicity
- nail infections (choose this, less toxic)
190
If a pt have a fungal nail infection, what drug should you choose and why?
- terbinafine
- less toxic
191
What are the side effects of terbinafine?
- GI complaints, not well absorbed
- rare hepatotoxicity and neutropenia (monitor LFTs)
192
What pregnancy category is terbinafine?
- category B
- wait until no longer pregnant - non-life-threatening illnesses are treated with this
193
What is the MOA of griseofulvin?
- allylamine
- inhibits fungal mitosis
- fungistatic
194
- Where does griseofulvin deposit? What does this allow for?
- Because this antifungal is fungistatic, it requires how long of therapy?
- How is this antifungal available?
- deposits in skin, protecting from further infection
- requires 2-6 months of therapy depending on infection
- oral suspension or tablets
195
- What can griseofulvin be used for?
- How must this be given?
- skin dermatophytoses and ring worm
- must be given with high fat mean
196
What are the side effects of griseofulvin?
- cytochrome interactions common
- contraindicated in pregnancy
- men should wait 6 months after therapy to have kids
