22. Infectious Diseases I: Background + Abx by Drug Class Flashcards
1
Q
S/sx of infection
A
Fever, elevated WBC, site-specific symptoms (e.g. dysuria with UTI)
Dx findings like culture results, X-rays, and markers of inflammation (e.g. procalcitonin)
2
Q
___ shows susceptibility patterns and can be used to monitor resistance trends over time
A
Antibiogram
3
Q
Gram-positive organisms: have (thick/thin) cell wall and stain (pink/purple) from ___
A
thick cell wall
purple
crystal violet stain
4
Q
Gram-negative organisms: have (thick/thin) cell wall and stain (pink/purple) from ____
A
thin cell wall
pink
safranin counterstain
5
Q
T/F: Atypical organisms do not have a cell wall and do not stain well
A
True
6
Q
Gram-positive: Cocci: Clusters examples
A
Staphylococcus spp. (including MSSA, MRSA)
7
Q
Gram-positive: Cocci: Pairs + Chains examples
A
Streptococcus pneumoniae (diplococci, pairs)
Streptococcus spp. (including Streptococcus pyogenes)
Enterococcus spp. (including VRE)
8
Q
Gram-positive: Bacilli (rods) examples
A
Listeria monocytogenes
Corynebacterium spp.
9
Q
Gram-positive: Anaerobes examples
A
Peptostreptococcus
Propionibacterium acnes
Clostridioides difficile
Clostridium spp.
10
Q
Gram-negative: Cocci examples
A
Neisseria spp.
11
Q
Gram-negative: Coccobacilli examples
A
Acinetobacter baumannii
Bordetella pertussis
Moraxella catarrhalis
12
Q
Gram-negative: Anaerobes examples
A
Bacteriodes fragilis
Prevotella spp.
13
Q
Gram-negative: Bacilli (rods): Colonize gut “enteric” examples
A
Proteus mirabilis
Escherichia coli
Klebsiella spp.
Serratia spp.
Enterobacter cloacae
Citrobacter spp.
14
Q
Gram-negative: Bacilli (rods): Do not colonize gut examples
A
Pseudomonas aeruginosa
Haemophilus influenzae
Providencia spp.
15
Q
Gram-negative: Curved or spiral shaped gram-negative rods examples
A
H. pylori
Campylobacter spp.
Treponema spp.
Borrelia spp.
Leptospira spp.
16
Q
Atypicals examples
A
Chlamydia spp.
Legionella spp.
Mycoplasma pneumoniae
Mycobacterium tuberculosis
17
Q
Common groups of organisms: PEK
A
Proteus
E. coli
Klebsiella
18
Q
Common groups of organisms: HNPEK
A
Haemophilus
Neisseria
Proteus
E. coli
Klebsiella
19
Q
Common groups of organisms: CAPES
A
Citrobater
Acinetobacter
Providencia
Enterobacter
Serratia
20
Q
Common groups of organisms: mouth flora (anaerobes)
A
Peptostreptococcus
21
Q
____ can be differentiated with a coagulase (enzyme) test. ___ is coagulase-positive
A
Staphylococci
Staphylococcus aureus
Note: other Staphylococcus spp. (e.g. S. epidermidis) are sometimes referred to as coagulase-negative staphylococci (CoNS)
22
Q
Explain how aminoglycosides and beta-lactams can have a synergistic effect when used for infective endocarditis
A
The beta-lactam allows the aminoglycoside to reach its intracellular target (the ribosome, where it causes lethal damage to the bacteria. without the beta-lactam, aminoglycosides cannot penetrate the cell wall at safe doses.
This synergy permits lower dose of aminoglycoside and clears the bloodstream infection more quickly
23
Q
What is intrinsic resistance?
A
The resistance is natural to the organism
For example, E. coli is resistant to vancomycin because the abx is too large to penetrate the bacterial cell wall of E. coli
24
Q
What is selection pressure?
A
Resistance occurs when abx kill off susceptible bacteria, leaving behind more resistant strains to multiply
For example, normal GI flora includes enterococcus. when abx (e.g. vancomycin) eliminate susceptible enterococci, vancomycin-resistant Enterococcus (VRE) can become more predominant
25
What is acquired resistance?
Bacterial DNA containing resistant genes can be transferred between different species and/or picked up from dead bacterial fragments in the environment
26
What is enzyme inactivation?
Enzymes produced by bacteria break down the abx
Examples: Beta-lactamase, extended-spectrum beta-lactamases (ESBLs), carbapenemases
27
Common resistant pathogen mnemonic: Kill Each And Every Strong Pathogen (KEAESP)
Klebsiella pneumoniae (ESBL, CRE)
Escherichia coli (ESBL, CRE)
Acinetobacter baumannii
Enterococcus faecalis, Enterococcus faecium (VRE)
Staphylococcus aureus (MRSA)
Pseudomonas aeruginosa
28
What does ESBL stand for?
Extended-spectrum beta-lactamase
29
What does VRE stand for?
Vancomycin-resistant Enterococcus
30
What does CRE stand for?
Carbapenem-resistant Enterobacterales
31
S/sx of C.diff infection (CDI)
Mild - loose stools and abdominal cramping
Severe - psuedomembranous colitis that can require colectomy or be fatal)
32
Which antibiotics have a warning for risk of CDI?
All abx have a warning for the risk of CDI but risk is highest with broad-spectrum penicillins and cephalosporins, quinolones, carbapenems, and clindamycin
Clindamycin has a boxed warning!
33
Which abx are cell wall inhibitors?
Beta-lactams (penicillins, cephalosporins, carbapenems)
Monobactams (aztreonam)
Vancomycin, dalbavancin, telavancin, oritavancin
34
Which abx are cell membrane inhibitors?
Polymixins
Daptomycin
Telavancin
Oritavancin
35
Which abx are DNA/RNA inhibitors
Quinolones (DNA gyrase, topoisomerase IV)
Metronidazole, tinidazole
Rifampin
36
Which abx are folic acid synthesis inhibitors?
Sulfonamides
Trimethoprim (often combined with sulfamethoxazole to overcome resistance)
Dapsone
37
Which abx are protein synthesis inhibitors?
Aminoglycosides
Macrolides
Tetracyclines
Clindamycin
Linezolid, tedizolid
Quinupristin/dalfopristin
38
Which antibiotics are hydrophilic?
Beta-lactams
Aminoglycosides
Vancomycin
Daptomycin
Polymixins
39
What are some PK characteristics predicted for hydrophilic agents?
1) small Vd (less tissue penetration)
2) mostly renally eliminated (drug accumulation and side effects (e.g. nephrotoxicity, seizures) can occur if not dose adj
3) Low intracellular conc (not active against atypical (intracellular) pathogens)
4) poor-moderate bioavailability (IV:PO ratio is not 1:1)
40
Which antibiotics are hydrophilic?
Quinolones
Macrolides
Rifampin
Linezolid
Tetracyclines
41
What are some PK characteristics predicted for lipophilic agents?
1) Large Vd (better tissue penetration)
2) Mostly hepatically metabolized (potential for hepatotoxicity and DDIs)
3) Achieve intracellular conc (active against atypical (intracellular) pathogens)
4) Excellent bioavailability (IV:PO ratio is often 1:1)
42
Concentration or time dependent killing?: dose less frequently and in higher doses to maximize conc about MIC
Concentration-dependent killing
43
Concentration or time dependent killing?: dose frequently or longer duration to maximize time above MIC
time-dependent killing
44
What are some examples of abx that are concentration-dependent (Cmax:MIC)? What is the goal and dosing strategies for these agents?
Aminoglycosides, quinolones, daptomycin
Goal: high peak (more killing), low trough (low toxicity)
Dosing strategies: large dose, long interval
45
What are some examples of abx that are exposure-dependent (AUC:MIC)? What is the goal and dosing strategies for these agents?
Vancomycin, macrolides, tetracyclines, polymyxins
Goal: exposure over time
Dosing strategies: variable
46
What are some examples of abx that are time-dependent (time > MIC)? What is the goal and dosing strategies for these agents?
Beta-lactams (penicillins, cephalosporins, carbapenems)
Goal: maintain drug level > MIC for most of dosing interval
Dosing strategies: shorter dosing interval, extended, or continuous infusions
47
What characterizes beta-lactams? Which abxs are included in this class?
Beta-lactam ring
Penicillins, cephalosporins, and carbapenems
48
MOA of beta-lactams
Inhibit bacterial cell wall synthesis by binding to penicillin binding protein (PBPs). Prevents the final step of peptidoglycan synthesis in bacterial cell walls.
49
Coverage: Natural penicillins (Penicillin V Potassium, Penicillin G Benzathine (Bicillin L-A))
Gram-positive cocci (streptococci and enterococci, but not staphylococci) and gram-positive anaerobes (mouth flora)
No GN activity
50
Coverage: Antistaphylococcal penicillins (Dicloxacillin, nafcillin, oxacillin)
Streptococci, MSSA
No activity against Enterococcus, GN pathogens, and anaerobes
51
Coverage: Aminopenicillins (Amoxicillin, Amox/Clav (Augmentin), Ampicillin, Amp/sulbactam (Unasyn))
Streptococci, enterococci, GP anaerobes (mouth flora), GN bacteria Haemophilus, Neisseria, Proteus, and E. coli
52
Coverage: Aminopenicillins + beta-lactamase inhibitors (Amoxicillin/Clavulanate (Augmentin), Ampicillin/Sulbactam (Unasyn))
Aminopenicillin coverage: Streptococci, enterococci, GP anaerobes (mouth flora), GN bacteria Haemophilus, Neisseria, Proteus, and E. coli
Additional coverage: MSSA, more resistant strains of GN bacteria (Haemophilus, Neisseria, Proteus, E. coli, Klebsiella (HNPEK) and GN anaerobes (B. fragilis)
53
Coverage: extended-spectrum penicillins + beta-lactamase inhibitors (piperacillin/tazobactam (Zosyn))
Broad-spectrum
Same as aminopenicillin/beta-lactamase inhibitor combinations PLUS other GN bacteria including Citrobacter, Acinetobacter, Providencia, Enterobacter Serratia (CAPES), and Pseudomonas)
54
Your NPO patient is indicated to use natural penicillins. Which options can you use?
Penicillin G Aqueous (Pfizerpen) - IV formulation
Penicillin G Benzathine (Bicillin L-A) - IM formulation
55
Which natural penicillin has a boxed warning? Why?
Penicillin G benzathione: not for IV use; can cause cardio-respiratory arrest and death
56
Your NPO patient is indicated to use antistaphylococcal penicillins. Which options can you use?
Nafcillin - IV/IM formulation
Oxacillin - IV formulation
57
What are contraindications for penicillins?
Type 1 hypersenstivity reaction to another penicillin or beta-lactam abx
Augmentin and Unasyn - hx of cholestatic jaundice or hepatic dysfunction a/w previous use
Severe renal impairment (CrCl <30): do not use ER oral forms of amoxicililn and amoxicillin/clavulanate (Augmentin XR) or the 875mg strength of amoxicillin/clavulanate
58
Which aminopenicillins come in chewable formulations?
Amoxicillin
Amoxicillin/clavulanate
59
What are common side effects of penicillins
Seizures (with accumulation when not correctly renal dose adj)
GI upset, diarrhea
Rash (SJS/TEN)/allergic reactions/anaphylaxis
Hemolytic anemia (identified with positive Coombs test)
Renal failure, myelosuppression with prolonged use, increased LFTs
60
What should you monitor for penicillins?
Renal function
Symptoms of anaphylaxis with 1st dose
CBC, and LFTs with prolonged courses
61
___ penicillins are preferred for MSSA soft tissue, bone and joint, edocarditis and bloodstream infections
Antistaphylococcal penicillins (dicloxacillin, nafcillin, oxacillin)
62
T/F: antistaphylococcal penicillins require renal dose adj
Flase - no renal dose adj
63
Which penicillin is a vesicant? What should be done if extravasation occurs?
Nafcillin is a vesicant - administration through central line is preferred
If extravasation occurs, use old packs and hyaluronidase injections
64
___ PO is rarely used d/t poor bioavailability. Amoxicillin is preferred if switching from IV.
Ampicillin
65
What ratio of amox/clav should be used to decrease diarrhea caused by clav component?
14:1
66
IV ampicillin and ampicillin/sulbactam must be diluted in ___ only
NS
67
Piperacillin/tazobactam contains ___mg Na per 1 gram of piperacillin
65mg
68
What is a typical dose for prolonged or extended infusion for piperacillin/tazobactam?
3.375-4.5g IV Q8H (each dose infused over 4 hours)
69
____ can increase the levels of beta-lactams by interfering with renal excretion
This combination is sometimes used intentionally in severe infections to increase abx levels
Probenecid
70
Penicillins can increase serum conc of ___
methotrexate
71
Beta-lactams except __ and ___ can enhance the anticoagulant effect of warfarin by inhibiting the production of vitamin K-dependent clotting factors. The excepts can inhibit the anticoagulant effect of warfarin.
nafcillin and dicloxacillin (CYP enzyme inducers)
72
Outpatient or oral options for penicillins
Penicillin VK
Amoxicillin
Amoxicillin/clavulanate (Augmentin)
Dicloxacillin
73
Inpatient options for penicillins
Penicillin G Benzathine (Bicillin L-A) - NOT used IV only PO
Nafcillin and Oxacillin
Piperacillin/Tazobactam (Zosyn)
74
What is penicillin VK typically used for?
First line treatment for pharyngitis ("strep throat") and mild non-purulent skin infections (no abscess)
75
What is amoxicillin typically used for?
First line treatment for acute otitis media (pediatric dose: 80-90mg/kg/day)
Drug of choice for infective endocarditis prophylaxis before dental procedures (2g PO x1, 30-60min before procedure)
Used in H. pylori treatment
76
What do we typically give to patients for infective endocarditis ppx before dental procedures?
Amoxicillin 2g PO x1, 30-60min before procedure
77
What is a typical pediatric amoxicillin dose for acute otitis media?
80-90mg/kg/day
78
What is amoxicillin/clavulanate (Augment) typically used for?
First line treatment for acute aotitis media (pediatric dose: 90mg/kg/day) and bacterial sinusitis (if abx indicated)
Note: use lowest dose of clavulanate to decrease diarrhea
79
What is a typical pediatric amox/clav dose for acute otitis media?
90mg/kg/day
80
What is dicloxacillin, nafcillin, and oxacillin typically used for?
MSSA soft tissue, bone and joint, endocarditis, and bloodstream infections (does NOT cover MRSA)
Note: no renal dose adj needed)
81
What is penicillin G Benzathine typically used for?
Drug of choice for syphilis (2.4 million units IM x1)
Note: NOT for IV use; can cause death
82
What is piperacillin/tazobactam (Zosyn) typically used for?
Only penicillin active against Pseudomonas
Note: extended infusions (4hrs) can be used to maximize T > MIC
83
Penicillins coverage varies by subgroup or type. As a class, they are NOT active against ___ or ___
MRSA or atypical
84
Cephalosporins coverage varies by generation. As a class, they are NOT active against ___ or ___
Enterococcus spp. or atypical
85
Coverage: 1st generation cephalosporins (cefazolin, cephalexin (Keflex), cefadroxil)
Excellent activity against GP cocci (e.g. streptococci and staphylococci)
Some activity against GN rods PEK
Generally less GN coverage compared to other generations
86
___ generation cephalosporins are preferred when a cephalosporin is used for MSSA infections
First generation cephalosporins
87
Coverage: 2nd generation cephalosporins (Cefuroxime, cefotetan, cefoxitin, cefaclor, cefprozil)
Cefuroxime - staphylococci, more resistant strains of S. pneumoniae and HNPEK
Cefoteta and cefoxitin - added activity against GN anaerobes (B. fragilis)
88
Coverage: 3rd generation cephalosporins: Group 1 (cefdinir, ceftriaxone, cefotaxime, cefixime (Suprax), cefpodoxime
Resistant streptococci (S. pneumoniae and viridans group streptococci)
Staphylococci
GP anaerobes
Resistant strains of HNPEK
89
Coverage: 3rd generation cephalosporins: Group 2 (ceftazidime (Fortaz, Tazicef))
Lacks GP activity but covers Pseudomonas
90
Coverage: 4th generation cephalosporins (cefepime)
Broad GN activity (HNPEK, CAPES, and pseudomonas)
Similar GP activity to ceftriaxone
91
Coverage: 5th generation cephalosporins (ceftaroline (Teflaro))
GN activity similar to ceftriaxone but broad GP activity
Only beta-lactam that covers MRSA
92
What is the only beta-lactam that covers MRSA
Ceftaroline (5th gen cephalosporin)
93
Coverage: beta-lactamase inhibitor combinations (ceftzidime/avibactam (Avycaz), ceftolozane/tazobactam (Zerbaxa))
Similar spectrum as ceftazidime but with added activity against MDR gram-negative rods
94
Coverage: Siderophore cephalosporin (cefiderocol (Fetroja))
E.coli, Enterobacter, Klebsiella, Proteus, and Pseudomonas
Note: uses iron transport system to enter GN cell wall
95
What is a typical dosing for cephalexin (Keflex)
250-500mg PO Q6-12H
96
What are contraindications for ceftriaxone?
Hyperbilirubinemic neonates (0-28 days) (causes biliary sludging, kernicterus)
Concurrent use with calcium-containing IV products in neonates ≤ 28 days old
97
All penicillins should be avoided in patients with a beta-lactam allergy. What is an exception?
Treatment of syphilis during pregnancy (all patients) or in patients with poor compliance/follow-up - desensitize and treat with penicillin G benzathine
98
D/t a small risk of cross-reactivity, cephalosporins should not be chosen on the NAPLEX if the patient has a penicillin allergy. What is an exception?
Pediatric patients with acute otitis media and a mild penicillin allergy (delayed onset reaction > 48 hrs after first abx dose, appearing as nonpruritic or mildly pruritic, maculopapular rash, but lacking systemic symptoms (e.g. hives, bronchospasm, anaphylaxis) or other serious reactions (SJS)
99
Cephalosporins as a class has a risk of ___ if accumulation occurs (e.g. failure to renal dose adj)
Seizures
100
Outpatient or oral options for cephalosporins
1st gen: cephalexin
2nd gen: cefuroxime
3rd gen: cefdinir
101
Inpatient options for cephalosporins
1st gen: cefazolin
2nd gen: cefotetan, cefoxitin
3rd gen: ceftriaxone, cefotaxime, ceftazidime
4th gen: cefepime
5th gen: ceftaroline
Combo: ceftolozane/tazobactam, ceftazidime/avibactam
102
What is cephalexin typically used for?
Skin infections (MSSA), strep throat
103
What is cefuroxime typically used for?
Acute otitis media, community-acquired pneumonia (CAP)
104
What is cefdinir typically used for?
Acute otitis media
105
What is cefazolin typically used for?
Surgical ppx
106
What is cefotetan and cefoxitin typically used for?
Anaerobic coverage (B. fragilis)
Surgical ppx (GI procedures)
107
___ (2nd get cephalosporin) can cause a disulfiram-like reaction with alcohol ingestion
Cefotetan
108
What is ceftriaxone and cefotaxime typically used for?
CAP, meningitis, spontaneous bacterial peritonitis, pyelonephritis
109
T/F: Ceftriaxone does not require renal dose adj
True
110
Which patient population cannot use ceftriaxone?
Neonates (0-28 days)
111
What is ceftazidime and cefepime typically used for?
Pseudomonas coverage
112
What is ceftolozane/tazobactam and ceftazidime/avibactam typically used for?
MDR gram-negative organisms (including Pseudomonas)
113
What is ceftaroline typically used for?
Only beta-lactam active against MRSA
CAP, skin and soft tissue infections
114
Coverage: Carbapenems
Very broad-spectrum, generally reserved for MDR gram-negative infections
Active against most GP, GN (including ESBL-producing bacteria) and anaerobic pathogens
Do NOT cover atypical pathogens, MRSA, VRE, C. diff or Stenotrophomonas
ErtAPenem does NOT cover PEA (Pseudomonas, Acinetobacter, or Enterococcus)
115
Which carbapenem does not have activity against Pseudomonas, Acinetobacter, or Enterococcus?
ertapenem
116
What are some warnings for carbapenems?
Do not use with PCN allergy (small risk of cross-reactivity)
CNS adverse effects, including confusion and seizures - higher risk with imipenem/cilastatin, larger doses, or impaired renal function
Doripenem: do not use for treatment of pneumonia, including HAP and VAP
117
What is a warning specific for doripenem?
do not use for treatment of pneumonia, including HAP and VAP
118
Which carbapenem is stable in NS only?
Ertapenem (Invanz)
119
What are some ADEs for carbapenems?
Diarrhea, rash/severe skin reaction (DRESS), bone marrow suppression with prolonged use, increased LFTs
120
What should you monitor for carbapenems?
Renal function, s/sx of anaphylaxis with 1st dose, CBC, LFTs
121
Why is imipenem combined with cilastin?
To prevent drug degradation by renal tubular dehydropeptidase
122
Carbapenems can decrease serum conc of ___, leading to a loss of seizure control
Valproic acid
123
What causes higher risk for seizure with carbapenem use?
imipenem/cilastatin use, larger doses, or failure to renal dose adj (renal impairment)
124
What are carbapenems typically used for?
Polymicrobial infections (e.g. severe diabetic foot infection)
Empiric therapy when resistant organisms suspected
ESBL-positive infections
Resistant Pseudomonas or Acinetobacter infections (except ertapenem)
125
T/F: Doripenem comes in PO formulation
False - all carbapenems are IV only
126
MOA of monobactam (aztreonam)
similar to beta-lactams
Inhibits cell wall synthesis by binding to penicillin binding proteins (PBPs), which prevents the final step of peptidoglycan synthesis in bacterial cell walls
127
Coverage: monobactam (aztreonam)
Many GN organisms, including pseudomonas and CAPES
No GP or anaerobic activity
128
T/F: aztreonam cannot be used when beta-lactam allergy is present d/t cross-reactivity
False - monobactam structure makes cross-reactivity with a beta-lactam unlikely, it is primarily used when a beta-lactam allergy is present
129
What are some ADEs of aztreonam (Azactam)
Similar to penicillin, rash, N/V/D, increased LFTs
130
What brand name of aztreonam is inhaled and used for cystic fibrosis?
Cayston
131
T/F: aztreonam requires renal dose adj
True
132
Which beta-lactams have atypical coverage
None
133
Penicillin Coverage Summary
Penicillin - strep/entero // mouth (peptostrepto)
Amoxicillin - strep/entero // PEK/HNPEK (no kleb coverage) // mouth
Oxacillin, Nafcillin - staph/strep ONLY
Amox/calv, amp/sulb - staph/strep/entero // PEK/HNPEK // mouth/B.frag
Pip/tazo - staph/strep/entero // PEK/HNPEK/CAPES/Pseudo // mouth/B.frag
MEMORIZE:
- categories from p345 (MRSA, MSSA, Strep pneumo, Viridans strepto, Entero, PEK, HNPEK, CAPES, pseudo, mouth, B. frag, atypicals)
- Nonsense but helps remember: Penicillin = strep enters through the mouth, amox = let him take a peek (HNPEK) but found no klebs
134
Which penicillins can be used for CAPES or pseudomonas?
Pip/tazo
135
Which penicillins can be used B.frag?
Amox/clav, amp/sulb, or pip/tazo
136
Which penicillins can be used for MSSA?
Oxacillin, nafcillin, amox/clav, amp/sulb, or pip/tazo
137
Which penicillins can be used for PEK or HNPEK?
Amoxicillin (no kleb coverage), amox/clav, amp/sulb, or pip/tazo
138
Which beta-lactam has only GN coverage?
Aztreonam (covers PEK/HNPEK/CAPES/Pseudo)
139
Which cephalosporins can be used for B. frag?
ceftazidime/avibactam or ceftolozane/tazobactam (must be given with metronidazole for full anaerobic coverage)
140
Which beta-lactam has similar coverage to pip/tazo?
Carbapenems except ertapenem
(MSSA to B.frag except they don't cover all enterococcus, only E. faecalis)
141
MAO of aminoglycosides
Bind to ribosome, which interferes with bacterial protein synthesis and results in a defective bacterial cell membrane
142
T/F: aminoglycosides are typically used as part of an empiric regimen as monotherapy given broad GN coverage
False - typically given with other antibiotics
Synergistic with beta-lactams for some GP organisms
143
T/F: aminoglycosides demonstrate time-dependent activity
False - conc-dependent activity
144
Aminoglycoside coverage
GN bacteria, including pseudomonas (primarily tobramycin)
145
Gentamicin and streptomycin are used for synergy, in combination with ___ or ___, when treating GP infections (e.g. enterococcal endocarditis)
beta-lactams or vancomycin
146
What are the 2 dosing strategies for aminoglycosides?
traditional dosing - lower doses more frequently
Extended interval dosing - higher doses (to attain higher peaks) less frequently
147
Although not proven to be clinically superior to traditional dosing, what is the benefit of using extended interval dosing for aminoglycosides?
Less accumulation of the drug
Lower risk of nephrotoxicity
Decrease cost
(gives kidneys time to recover between doses)
148
T/F: Aminoglycosides do not have post-antibiotic effect
False - it does have a post-antibiotic effect (bacterial killing continues after serum level drops below MIC)
149
What should be monitored with aminoglycosides?
Nephrotoxicity, ototoxicty (may be irreversible hearing loss/tinnitus/balance problems)
150
Aminoglycoside examples
Gentamicin, tobramycin, amikacin, streptomycin, plazomicin
151
What is typical gentamicin and tobramycin IV traditional dosing
1-2.5 mg/kg/dose (lower doses for GP infections, higher doses for GN infections)
152
For CrCl ≥ 60, what is the dosing interval for aminoglycosides (traditional dosing)?
Q8H
153
What is the renal dose adj CrCl cut off for aminoglycosides?
CrCl < 60
154
What is typical gentamicin and tobramycin IV extended interval dosing?
4-7 mg/kg/dose (commonly 7mg/kg)
Frequency determined by nomogram (shortest interval is Q24H if renal function normal)
155
When should extended interval IV dosing be avoided for aminoglycosides?
when clearance and/or Vd are altered (e.g. pregnancy, ascites, brunes, cystic fibrosis, CrCl < 30 including ESRD on dialysis)
156
What are boxed warnings for aminoglycosides?
Nephrotoxicity, ototoxicity, neuromuscular blockade, and respiratory paralysis
AVOID with other neurotoxic/nephrotoxic drugs
Fetal harm if given in pregnancy
157
What are warnings for aminoglycosides?
Use caution in patients with impaired renal function, in the elderly, and concomitant use with nephrotoxic drugs (amphotericin B, cisplatin, polymyxins, cyclosporine, loop diuretics, NSAIDs, radio constrast dye, tacrolimus, vancomycin)
158
What to monitor for aminoglycosides?
Drug levels, renal function, hearting tests, urine output
Traditional dosing: trough immediately before 4th dose, peak 30 min after end of 30 min infusion for 4th dose
Extended interval dosing: random level per the timing on the nomogram
159
What is trough goal for gentamycin (GN infection ) and tobramycin traditional dosing?
<2 mcg/mL
160
For obese patients (TBW > 120% IBW), what body weight should be used for aminoglycoside dosing?
adjusted body weight
161
For underweight patients (TBW < IBW), what body weight should be used for aminoglycoside dosing?
Total body weight
162
MOA of quinolones
inhibit bacterial DNA topoisomerase IV and DNA gyrase (topoisomerase II), prevents supercoiling of DNA and promotes breakage of double-stranded DNA
163
T/F: Quinolones have time-dependent abx activity
False - conc-dependent
164
Which quinolones are referred to as "respiratory quinolones" d/t their enhanced coverage of S. pneumoniae and atypical pathogens?
Levofloxacin and moxifloxacin
165
Which quinolones have enhanced GN activity, including pseudomonas?
Ciprofloxacin and levofloxacin
166
____ is active against MRSA and is the preferred quinolone if treating skin infections suspected to be caused by MRSA. Other quinolones should generally be avoided d/t high rates of MRSA resistance.
Delafloxacin
167
What is in combo med ear drops Ciprodex?
Ciprofloxacin + dexamethasone
168
All quinolones require renal dose adj EXCEPT ____
Moxifloxacin
169
What are boxed warnings for quinolones
Tendon inflammation and/or rupture (increased risk with concurrent use of systemic steroids, organ transplant patients, >60 yo)
Peripheral neuropathy
CNS effects - seizures!
Avoid in patients with myasthenia gravis (may exacerbate muscle weakness)
Use last-line (only if no other possible treatment) for: acute bacterial sinusitis, acute exacerbation or chronic bronchitis and uncomplicated UTI
170
Contraindications for ciprofloxacin
Concurrent administration of tizanidine
171
What are warnings for quinolones ?
QT prolongation (highest risk with moxi > levo > cipro)
Hypoglycemia and hyperglycemia
Psychiatric disturbances
Avoid systemic quinolones in children and in pregnancy/breastfeeding (musculoskeletal toxicity, exception: anthrax exposure)
Aortic aneurysm and dissection (increased risk with longer durations of therapy or history of peripheral vascular disease, atherosclerosis or prior aneurysms)
Photosensitivity, hepatotoxicity, crystalluria (stay hydrated)
172
Side effects for Quinolones
N/D, HA, dizziness, SJS/TEN
173
Which quinolone should not be used for UTIs as it does not concentrate in the urine?
Moxifloxacin
174
What are some things to note for ciprofloxacin and patients with feeding tubes?
Cipro oral solution: shake vigorously for 15 sec before each dose. Do NOT put through NG or other feeding tube (oil-based suspension adheres to tubing)
Cipro: can crush IR tablets, mix with water and give via a feeding tube. Hold tube feedings at least 1 hour before and 2 hours after the dose
175
Which cipro formulation is most appropriate for patients with feeding tubes: crushed PO tabs or PO solution?
PO Tab - IR tabs can be crushed, mixed with water and given via feeding tube
PO solution should NOT be given via feeding tube (oil-based suspension - adheres to tubing)
176
What increases risk of tendon inflammation and/or rupture with quinolone use?
Concurrent use of systemic steroids
Organ transplant patients
Age > 60yo
177
Which drugs should be separated from quinolones d/t chelation and inhibition of quinolone absorption?
Antacids and other polyvalent cations (Mg, Al, phosphate, Ca, iron, zinc), multivitamins, sucralfate, and bile acid resins
178
Phosphate binders lanthanum carbonate and sevelamer can (increase/decrease) serum conc of oral quinolones. Separate administration by at least _____ before and at least ____ after lanthanum or ___ after sevelamer
Decrease serum conc of oral quinolones
2 hrs before
2 hrs after (with lanthanum)
6 hrs after (with sevelamer)
179
Quinolones can (increase/decrease) effects of warfarin
increase
180
Quinolones can (increase/decrease) effects of SU, insulins, and other hypoglycemic drugs
Increase
181
Ciprofloxacin is a strong CYP ____ inhibitor, a weak CYP3A4 inhibitor, and a Pgp substrate. Ciprofloxacin can (decrease/increase) levels of caffeine, theophylline, and tizanidine.
CYP1A2
Increase levels
182
Common uses of quinolones
Varies by agent: pneumonias, UTIs, intra-abdominal infections, traveler's diarrhea
183
Which quinolones are respiratory quinolones?
Levofloxacin, moxifloxacin
(Reliable strep pneumo activity in pneumonia)
184
Which quinolones have pseudomonal coverage?
Ciprofloxacin, levofloxacin
(used for pseudomonas infections, including pneumonia)
185
Which quinolones have a IV to PO 1:1 ratio?
Levofloxacin and moxifloxacin
186
Quinolone profile review tips
Caution with CVD, Decrease K/Mg, and with other QT-prolonging drugs (e.g. azole antifungals, antipsychotics, methadone, macrolides)
Avoid in pts with seizure hx or if using seizure drugs
Avoid in children
187
Some counseling points for quinolones
Avoid sun exposure, separate from polyvalent cations, monitor BG (in diabetes)
Watch fro tendon rupture, neuropathy, CNS, or psychiatric side effects
188
MOA of macrolides
Bind to 50S ribosomal subunit, resulting in inhibition of RNA-dependent protein synthesis
189
Quinolones end in "-____"
-floxacin
190
Macrolides end in "-____"
-thromycin
191
Azithromycin (Z-pak) dosing
500mg on day 1 and then 250mg on days 2-5
(two 250mg x1, 250mg PO daily x4 days)
192
Azithromycin (Tri-Pak) dosing
500mg daily for 3 days
193
Contraindications for Macrolides
History of cholestatic jaundice/hepatic dysfunction with prior use
Clarithromycin and erythromycin: do NOT use with lovastatin or simvastatin, pimozide, ergotamine, or dihydroergotamine
Clarithromycin: concurrent use with colchicine in pts with renal or hepatic impairment
194
Which macrolides do NOT require renal dose adj
Azithromycin and erythromycin
195
Macrolide warnings
QTC prolongation (highest risk with erythromycin>azithromcyin>clarithromycin)
Hepatotoxicity
Exacerbation of myasthenia gravis
Clarithromycin: caution in pts with CAD (increased mortality documented ≥ 1 yr after end of 2 week course of treatment)
196
Macrolide side effects
GI upset (diarrhea, abd pain, cramping)
Taste perversion
Ototoxicity (rare, reversible) severe (but rare) skin reactions (SJS/TEN/DRESS)
197
Erythromycin and clarithromycin are major substrates and (mod for erythro, strong clarithro) inhibitors of CYP___
CYP3A4
Lovastatin and simvastatin contraindicated to use with erythromycin and clarithromycin for this reason
Caution with warfarin
198
Which macrolide is a minor substrate of CYP3A4 and a weak inhibitor of CYP1A2 and P-gp; fever clinically significant drug interactions that other macrolides
Azithromcyin
199
Common uses of macrolides in general
CAP and as an alternative to beta-lactam for pharyngitis ("strep throat")
200
Common uses of azithromycin
COPD exacerbations, pertussis, chlamydia (in pregnant patients), prophylaxis for Mycobacterium avium complex, severe traveler's diarrhea (including dysentery, diarrhea with bloody stools)
201
Common uses of clarithromycin
H. pylori treatment regimens
202
Common uses of erythromycin
Gastroparesis (erythromycin increases gastric motility)
203
MOA of tetracyclines
Inhibit bacterial protein synthesis by reversibly binding to 30S ribosomal subunit
204
Which tetracycline has broader indications than the other tetracyclines including respiratory tract infections (e.g. CAP), tickborne/rickettsial diseases, spirochetes and STIs (e.g. chlamydia)?
Doxycycline
205
Which tetracycline is an option for the treatment of mild CA-MRSA skin infections and VRE UTIs?
Doxycycline
206
Which tetracycline is often preferred for acne?
Minocycline
207
Which tetracycline does not require renal dose adj: minocycline or doxycycline?
Doxycycline
208
What are some warnings for tetracyclines?
Children <8yo, pregnancy and breastfeeding (suppress bone growth and skeletal development, and permanently discolors teeth)
Photosensitivity, tissue hyperpigmentation, severe skin reactions (DRESS/SJS/TEN), exfoliative dermatitis
GI inflammation/ulceration
Minocycline: drug-induced lupus erythematosus (DILE)
209
Which tetracycline has a warning for drug-induced lupus erythematosus (DILE)?
Minocycline
210
ADEs of tetracyclines
N/V/D, rash
211
Which tetracyclines have IV:PO ratio 1:1?
Doxycycline, minocycline
212
What are some things to note for administration of tetracycline?
Tabs and caps should be taken with 8 oz of water
For doxycycline, sit upright for at least 30 min after dose to avoid esophageal irritation
213
For which tetracycline is it recommended to sit up for 30 min after taking to avoid esophageal irritation?
Doxycycline
214
Which drugs should be separated from tetracyclines to avoid chelation and inhibition of tetracycline absorption?
Antacids, polyvalent cations (e.g. Mg, Al, phosphate, Ca, iron, zinc), multivitamins, sucralfate, bismuth subsalicylate, and bile acid resins
Separate 1-2 hours before or 4 hours after chelating drug
Dairy products should be avoided 1 hr before and 2 hrs after tetracycline
215
Lanthanum can (increase/decrease) conc of tetracycline derivatives; take tetracycline at least 2 hours before or after lanthanum
Decrease
216
MOA of sulfamethoxazole/trimethoprim (Bactrim)
SMX = inhibits dihydrofolic acid formation from para-aminobenzoic acid, which interferes with bacterial folic acid synthesis
TMP = inhibits dihydrofolic acid reduction to tetrahydrofolate, resulting in inhibition of folic acid pathway
217
Is SMX/TMP dosing based on SMX or TMP components?
TMP
218
How much of each component is in Bactrim single strength (SS)
400mg SMX
80mg TMP
219
How much of each component is in Bactrim double strength (DS)
800mg SMX
160mg TMP
220
All SMX/TMP products are formulated with a SMX:TMP ratio of ____
5:1
221
What is typical Bactrim dosing to uncomplicated UTI?
1 DS tablet PO BID x 3 days
222
What is typical Bactrim dosing to Pneumocystis Pneumonia (PCP) Prophylaxis?
1 DS or SS tablet daily
223
Contraindications for SMX/TMP
Sulfa allergy
Anemia d/t folate deficiency, renal or hepatic disease, infants <2 mo
224
Warnings for SMX/TMP
Blood dyscrasias, including agranulocytosis and aplastic anemia
Skin reactions: SJS/TEN, TTP
Hemolytic anemia: can be immune-mediated (identified with positive Coombs test) or caused by G6PD deficiency (do NOT use with known deficiency)
Hypoglycemia, thrombocytopenia
Pregnancy - only use if benefit outweighs risk (blocks folic acid metabolism = congenital defects)
225
ADEs for SMX/TMP
Photosensitivity, increased K, crystalluria (take with 8oz of water)
N/V/D
anorexia, skin rash, decreased folate, false elevations in SCr (d/t inhibition of creatinine tubular secretion), renal failure
226
SMX/TMP is a moderate-strong CYP ___ and CYP___ inhibitor and can cause significantly (increase/decrease) in INR if used with warfarin
2C8 and 2C9 inhibitor
Increase INR
227
SMX/TMP can enhance toxic effects of ____
Methotrexate
228
Therapeutic effects of SMX/TMP can be diminished by use of ___ or ___
leucovorin or levoleucovorin
229
What increases risk of hyperkalemia in patients using SMX/TMP
renal dysfunction or if used in combo with ACEi/ARBs, aliskiren, aldosterone receptor antagonists, K-sparing diuretics, cyclosporin, tacrolimus, NSAIDs, drospirenone-containing oral contraceptives or canagliflozin
230
Common uses for SMX/TMP
CA-MRSA skin infections, UTI, Pneumocystis pneumonia (PCP)
231
MOA of vancomycin
Inhibits bacterial cell wall synthesis by binding to the D-alanyl-D-alanine cell wall precursor and blocking peptidoglycan polymerization
232
Coverage of vancomycin
GP coverage only, includes MRSA, streptococci, enterococci (not VRE), and C. difficile (PO vanc only)
233
Vancomycin is typically first-line treatment for moderate-severe systemic RMSA infections. When would we consider an alternative drug?
If MRSA MIC ≥ 2mcg/mL
234
Typical vancomycin IV dosing
15-20mg/kg q8-12h
dosing based on total body weight
Q24H if CrCl 20-49
235
What type of weight is vancomycin dosing based on?
Total body weight
236
Typical vancomycin PO dosing
125 QID x 10 day
No renal dose adj required
237
T/F: PO vancomycin does not require renal dose adj
True
238
Warnings for vancomycin
Ototoxicity and nephrotoxicity
PO only for C.diff (not for systemic infections)
Vancomycin infusion reaction
239
Monitoring for vancomycin
Renal function, drug levels (AUC/MIC ratio, or trough after 4th or 5th dose)
Serious MRSA infections (e.g. bacteremia, sepsis, endocarditis, pneumonia, osteomyelitis, meningitis): AUC/MIC ratio of 400-600 or goal trough of 15-20mcg/mL
240
Vancomycin has increased risk of nephrotoxicity when used with other nephrotoxic drugs such as ____
Aminoglycosides, amphotericin B, cisplatin, polymyxins, cyclosporine, tacrolimus, loop diuretics, NSAIDs, and radiographic contrast dye
241
Vancomycin has increased risk of ototoxicity when used with other ototoxic drugs such as ____
aminoglycosides, cisplatin, loop diuretics
242
Lipoglycopeptides end with "-____"
-vancin
243
MOA of lipoglycopeptides (telavancin, oritavancin, dalbavancin)
Inhibit bacterial cell wall synthesis by 1) binding to D-alanyl-D-alanine portion of the cell wall, blocking polymerization and cross-linking of peptidoglycan and 2) disrupting bacterial cell membrane potential and changing cell permeability (d/t presence of lipophilic side chain)
244
T/F: lipoglycopeptides have time-dependent activity
False - conc-dependent
245
Lipoglycopeptides have similar coverage to vancomycin with the exception of ___
they only come in IV form and cannot be used to treat C. diff infections
246
Boxed warnings for telavancin
Fetal risk - requires pregnancy test prior to starting therapy
Nephrotoxicity
Increased mortality with pre-existing moderate-to-severe renal impairment (CrCl ≤ 50) compared to vancomycin in pneumonia trials
247
Contraindications for oritavancin
Do NOT use IV UFH for 120 hours (5 days) after oritavancin d/t interference (false elevations ) with aPTT laboratory results
248
Contraindications for telavancin
Do NOT use with IV UFH
249
Warnings for lipoglycopeptides
General: infusion reaction (similar to vancomycin) with rapid IV administration
Oritavancin and telavancin: can falsely increase aPTT/PT/INR but do NOT increase bleeding risk
Telavancin: QT prolongation
Oritavancin: use a diff abx if osteomyelitis is confirmed or suspected
Dalbavancin: increased ALT > 3x ULN
250
T/F: Oritavancin and telavancin are contraindicated with concurrent use of IV UFH because increased bleeding risk
False - they are contraindicated with concurrent use of IV UFH because they falsely increase aPTT/PT/INR but do NOT increase bleeding risk
251
MOA daptomycin (cyclic lipopeptide)
Binds to cell membrane components, causing rapid depolarization; inhibits all intracellular replication processes, including protein synthesis, and causes cell death
252
Daptomycin has __-dependent activity against most gram-___ bacteria, including __ and ___
concentration-dependent activity
gram-positive bacteria including MRSA and VRE
Note: NO activity against GN
253
Why can you NOT use daptomycin for pneumonia?
Drug is inactivated in the lungs by surfactant
254
Which antibiotic cannot be used for pneumonia because it is inactivated in the lungs by surfactant?
Daptomycin
255
Warnings for daptomycin
Myopathy and rhabdomyolysis: d/c in pts with s/sx and CPK > 1000 units/L (5x ULN) or in asymptomatic patients with a CPK ≥ 2000 units/L (10x ULN); consider holding statins
Can falsely increase PT/INR but does NOT increase bleeding risk
Peripheral neuropathy
Eosinophilic pneumonia - generally develops 2-4 weeks after treatment initiation
256
Side effects for daptomycin
Increase CPK, abdominal pain, pruritus, chest pain, edema, HTN, AKI
257
Monitoring for daptomycin
CPK (more frequent if on statin or with renal impairment; muscle pain/weakness, s/sx of neuropathy, dyspena
258
Notes for daptomycin and diluent compatibility
Cubicin: compatible with NS and LR (no dextrose )
Cubicin RF: compatible with NS (no dextrose) but must use only sterile or bacteriostatic water for injection to reconstitute the lyophilized powder (before diluting further with NS)
259
MOA of oxazolidinones (linezolid, tedizolid)
Bind to 50S subunit of bacterial ribosome, inhibiting translation and protein synthesis.
260
Contraindications for linezolid
Do NOT use with or within 2 weeks of MAOi
261
Warnings for linezolid
Duration-related myelosuppression (thrombocytopenia, anemia, leukopenia) when used > 14 days, peripheral and optic neuropathy when used >28 days, serotonin syndrome, hypoglycemia (caution with insulin or other hypoglycemic drugs), seizures, lactic acidosis, increased BP (caution and monitor BP in pts with uncontrolled HTN and untreated hyperthyroidism)
262
Side effects for linezolid
Decreased platelets, Hgb, WBC
HA, nausea, diarrhea
Increased LFTs
263
Monitoring for linezolid
Weekly CBC, HR, BP, BG (in DM), visual function
264
T/F: linezolid suspensions should be shaken vigorously for 15 seconds prior to administration.
False - do NOT shake linezolid suspensions
265
Linezolid and tedizolid are reversible ____ inhibitors. Avoid ___ containing foods and ____ drugs
Reversible MAO inhibitors
Tyramine-containing foods
Seotonergic drugs
266
MOA Quinuprisitin/Dalfopristin (Synercid)
50 S ribosomal subunit inhibiting protein synthesis
266
Quinupristin/Dalfopristin covers most gram-positive bacteria, including MRSA and VRE but only VRE caused by ___ but not ____
Covers E. faecium but not E. faecalis
267
T/F: Quinupristin/dalfopristin is often drug of choice for complicated SSTIs and well tolerated
False - not well-tolerated, typically limited to vancomycin-resistant E. faecium infections
268
Side effects for quinupristin/dalfopristin (Synercid)
Arthralgias/myalgias, infusion reactions (edema and pain at infusion site), phlebitis, hyperbilirubinemia, CPK elevations, GI upset, increased LFTs
269
Quinupristin/dalfopristin can only be diluted in ___
D5W only
270
Quinupristin/dalfopristin should be administered via ___ to avoid phlebitis
central line, such as a peripherally inserted central catheter (PICC)
271
MOA Tigecycline
Binds to 30S ribosomal subunit and inhibits protein synthesis; structurally related to tetracyclines
272
Coverage Tigecycline
Broad-spectrum including MRSA, VRE, GN bacteria, anaerobes, and atypical
Among gram-negatives, NO activity against 3 Ps: Pseudomonas, Proteus, Providencia
273
Boxed warning for tigecycline
Increased risk of death (only use when alt treatments not suitable)
274
Common uses for tigecycline
complicated SSTIs
Intra-abdominal infections
CAP
Note: Do NOT use for bloodstream infections, does not achieve adequate concentrations in the blood since it is lipophilic drug
275
T/F: tigecycline is a broad-spectrum abx that can be used for complicated SSTIs and bloodstream infections
It is used for complicated SSTIs but cannot be used for bloodstream infections as it does not achieve adequate concentrations in the blood (lipophilic drug)
276
T/F: When tigecycline is reconstituted, it should be a light purple solution; discard if not this color
False - should be yellow-orange; discard if not this color
277
Warnings for Colistimethate
dose-dependent nephrotoxicity
Neurotoxicity
278
Which polymyxin is a prodrug?
Colistimethate is a prodrug that is converted to colistin (active form)
279
1 mg = ____ units polymyxin B
10,000 units
280
Boxed warning for polymyxin B
Nephrotoxicity (dose-dependent)
Neurotoxicity (dizziness, tingling, numbness, paresthesia, vertigo) - can result in respiratory paralysis from neuromuscular blockade!
Should only be administered to hospitalized patient
Avoid concurrent or sequential use of other neurotoxic or nephrotoxic drugs
281
MOA chloramphenicol
Reversible binds to 50S subunit of bacterial ribosome, inhibiting protein synthesis
282
Boxed warning for chloramphenicol
Serious and fatal blood dyscrasias (aplastic anemia, pancytopenia - may be irreversible)
283
Chloramphenicol can cause ___ with high serum levels - circulatory collapse, cyanosis, acidosis, abdominal distention, myocardial depression, coma, and death
Gray syndrome
284
T/F: Chloramphenicol is rarely used d/t adverse effects
True
285
MOA clindamycin
Reversibly binds to 50S subunit of bacterial ribosome, inhibiting protein synthesis
286
Boxed warning with clindamycin
Colitis (C. diff)
287
___ test should be performed on S. aureus that is susceptible to clindamycin but resistant to erythromycin
induction test (D-test)
A flattened zone between disks (positive D-test) indicated inducible clindamycin resistance and clindamycin should NOT be used
288
Common uses of clindamycin
Purulent and non-purulent skin infections, beta-lactam alternative for dental abscesses and surgery prophylaxis
289
T/F: clindamycin does not require renal dose adj
True
290
MOA metronidazole
Cause loss of helical DNA structure and strang breakage resulting in inhibition of protein synthesis
291
Coverage metronidazole
Anaerobes and protozoal organisms
292
Common uses for metronidazole (Flagyl)
Bacterial vaginosis, trichomoniasis, giardiasis, amebiasis, C.diff (not preferred), and used in combo regimens for intra-abdominal infections
293
Contraindications for metronidazole/tinidazole
Pregnancy (1st trimester), use of alcohol or propylene-glycol-containing products during treatment or within 3 days of treatment d/c (disulfiram reaction - abdominal cramping, HA, N/V, flushing)
Metronidazole: use of disulfiram within the past 2 weeks
Tinidazole: breastfeeding
294
Warnings for metronidazole/tinidazole
CNS effects: seizures, peripheral neuropathy
Metronidazole: aseptic meningitis, encephalopathy, optic neuropathy
295
Side effects for metronidazole/tinidazole
Metallic taste, HA, nausea, furry tongue, darkened urine, dizziness, rash/severe skin rxn (SJS/TEN)
296
Side effects for secnidazole (Solosec)
Vulvovaginal candidiasis, HA, N/D
297
Which antibiotic should not be used with alcohol (during and for 3 days after discontinuation) d/t potential disulfiram-like reaction?
Metronidazole
298
Metronidazole is a weak inhibitor of CYP___ and can cause increase in INR in warfarin pts
2C9
299
MOA lefamulin
Inhibits bacteria protein synthesis by binding to peptidyl transferase center of the 50S ribosomal subunit
300
Contraindications of Lefamulin (Xenleta)
Use with CYP3A4 substates that prolong QT interval
301
Warnings of Lefamulin (Xenleta)
Avoid in preganncy (teratogenic)
QT prolongation
C.diff assocaited diarrhea
302
MOA fidaxomicin
inhibits RNA polymerase, resulting in inhibition of protein synthesis and cell death
303
Common uses of fidaxomicin
C diff infections (not effective for systemic infections - absorption is minimal)
304
MOA rifaximin
inhibits bacterial RNA synthesis by binding to bacterial DNA-dependent RNA polymerase
305
Common uses for rifaximin
Travelers' diarrhea
Decrease recurrence of hepatic encephalopathy
IBS-D
NOT effective for systemic infections (<1% absorption)
Used off-label for C. diff infections
306
MOA Fosfomycin
Inhibits bacterial cell wall synthesis by inactivating the enzyme pyruval transferase, which is critical in the synthesis of cell walls
307
What is typical dose for fosfomycin in uncomplicated UTI?
3 g PO x1, mixed in 3-4 oz of cold water (comes in packet granules)
308
Fosfomycin comes in packet granules. How much is in 1 packet?
3g
309
MOA nitrofurantoin
Bacterial cell wall inhibitor
310
Typical nitrofurantoin (Macrobid) dosing
100mg BID x 5 days
Macrobid (macrocrystal formulation) dissolves more slowly and is given BID
311
Contraindications for nitrofurantoin
Renal impairment CrCl <60 - inadequate urine conc and risk for accumulation of neurotoxins
Previous hx of cholestatic jaundice/hepatic dysfunction
Pregnancy (at term)
312
Warnings for nitrofurantoin
G6PD deficiency (can cause hemolytic anemia; do not use if known deficiency)
Optic neuritis, hepatic toxicity, peripheral neuropathy, pulmonary toxicity
313
Side effects for nitrofurantoin
GI upset (take with food), HA, rash, brown urine discoloration (harmless)
314
Common uses for Mupirocin
topical antimicrobial nasal ointment for MRSA in the nostrils
315
Commonly used abx used for C.diff
PO vanco
Fidaxomicin
Metronidazole (not preferred)
316
Commonly used abx with B.fragilis coverage
Metronidazole
Beta-lactam combos: amox/clav, amp/sulb, pip/tazo, ceftazidime/avibactam, ceftolozane/tazobactam
Cefotetan, cefoxitin
Carbapenems
Moxifloxacin (reduced activity)
317
Commonly used abx with Carbapenem-resistant GN rods (CRE) coverage
Ceftazidime/avibactam
Colistimethate, polymyxin B
Meropenem, vaborbactam
Imipenem/cilastin/relebactam
318
Commonly used abx with ESBL producing GN rods (E.coli, K. pneumoniae, P. mirabilis) coverage
Carbapenems
Ceftazidime/avibactam, ceftolozane/tazobactam
319
Commonly used abx with CAPES coverage
Pip/tazo
Cefepime
Carbapenems
Aminoglycosides
Colistimethate, polymyxin B
320
Commonly used abx with Pseudomonas coverage
Pip/tazo
Cefepime
Ceftazidime
Ceftazidime/avibactam, ceftolozane/tazobactam
Carbapenems (except ertapenem)
Ciprofloxacin, levofloxacin
Aztreonam
Tobramycin
Colistimethate, polymyxin B
321
Commonly used abx with HNPEK coverage
Beta-lactam combos: Amox/clav, amp/sulb, pip/tazo, ceftazidime/avibactam, ceftolozane/tazobactam
Cephalosporins (except 1st gen)
Carbapenems
Aminoglycosides
Quinolones
SMX/TMP
322
Commonly used abx with atypical organisms coverage
Azithromycin, clarithromycin
Doxycycline, minocycline
Quinolones
323
Commonly used abx with VRE coverage
Pen G or ampicillin (E. faecalis only)
Linezolid
Daptomycin
Cystitis only: nitrofurantoin, fosfomycin, doxycycline
324
Commonly used abx with MRSA coverage
Vancomycin (consider alt if MIC ≥2)
Linezolid
Daptomycin (not in pneumonia)
Ceftaroline
SMX/TMP (CA-MRSA SSTIs)
Doxycycline, minocycline (CA-MRSA SSTIs)
Clindamycin (CA-MRSA SSTIs - D-test must be preformed before using clinda)
325
Commonly used abx with MSSA coverage
Dicloxacillin, nafcillin, oxacillin
Cefazolin, cephalexin (and other 1st and 2nd gen cephalosporins)
Amox/clav, amp/sulb
326
Liquid oral antibiotics: Refrigeration required after reconstitution
Pencillin VK
Ampicillin
Amoxicillin/clavulanate
(other to know: cephalexin, cefadroxil, cefpodoxime, cefprozil, cefuroxime, cefaclor, vancomycin PO, valganciclovir)
327
Liquid oral antibiotics: Refrigeration recommended
Amoxicillin - improves taste
328
Liquid oral antibiotics: Do NOT refrigerate
Cefdinir
(others to know: azithromycin, clarithromycin - bitter taste, thickens/gels, doxycycline, ciprofloxacin, levofloxacin, clindamycin - thickens, may crystalize, linezolid, SMX/TMP, acyclovir, fluconazole, posaconazole, voriconazole, nystatin)
329
IV antibiotics: Do NOT refrigerate
Metronidazole
Moxifloxacin
SMX/TMP
Acyclovir - refrigeration causes crystallization
330
Abx that do NOT require renal dose adj
Key drugs:
Antistaphylococcal PCN (e.g. dicloxacillin, nafcillin)
Ceftriaxone
Clindamycin
Doxycycline
Macrolides (azithromycin and erythromycin only)
Metronidazole
Moxifloxacin
Linezolid
(Others to know: Chloramphenicol, fidaxomicin, select tetracyclines (e.g. eravacycline, seracycline, omadacycline), quinupristin/dalfopristin, rifaximin, rifampin, tedizolid, tigecycline, tinidazole, vancomycin PO only)
331
Most abx can be taken with food to decrease GI upset. Which ones should be taken on an empty stomach?
Ampicillin oral capsules and suspension
Levofloxacin oral soltion
Pneicillin VK
Rifampin
Isoniazid
Itraconazole solution
Voriconazole
332
Which abx should be taken within 1 hour of finishing a meal
Amoxicillin ER
333
Which abx have 1:1 IV to PO ratios?
Levofloxacin, moxifloxacin
Doxycycline, minocycline
Linezolid, tedizolid
Metronidazole
SMX/TMP
Fluconazole, isavuconazonium, posaconazole (oral tabs and IV), voriconazole
334
Which abx require light protection?
Doxycycline
Micafungin
Pentamidine
335
Which Abx are compatible with dextrose ONLY
quinupristin/dalfopristin
SMX/TMP
Amphotericin B (conventional, Abelcet, Ambisome)
Pentamidine
336
Which abx are compatible with saline ONLY
Ampicillin
Amp/sulb
Ertapenem
Daptomycin (Cubicin RF)
337
Which abx are compatible with NS/LR ONLY
Caspofungin
Daptomycin (Cubicin)
