Antibiotics Flashcards
1
Q
Empiric therapy
A
ABx coverage for the “likely” cause, don’t have actual culture results yet
2
Q
Signs and symptoms of infection include
A
Fever > 38 C
Elevated WBC >10,000 cells/ml
3
Q
What are some other causes of fever, other then infection?
A
Drug induced (beta lactic, allopurinol, anticonvulsants)
Disease induced (autoimmune, malignancies)
Fever can be masked by antipyretics (NSAIDS, acetaminophen)
4
Q
Low WBX (<4000 cells/mL) associated with ________ outcomes
A
Poorer
5
Q
What are some non-infectious etiologies for leukocytosis?
A
MI, trauma, leukemia
6
Q
Pain/inflammation, swelling, erythema, tenderness or purulent drainage could indicate what kind of infection?
A
Superficial or Bone/joint infections
7
Q
Pneumonia
Meningitis
Endocarditis
UTI
could indicate what kind of infection
A
Deep-seated
8
Q
Flank pain associated with
A
Pyelonephritis
9
Q
What microbiology sample should we (ideally) obtain prior to ABx therapy
A
Gram stain
Cultures
10
Q
Two types of gram stain patterns
A
Positive (purple)
Negative (pink)
11
Q
Types of shapes under gram stain
A
Cocci (sphere) or bacilli (rod)
12
Q
Types of growth patterns under gram stain
A
Clusters, chains, pairs
13
Q
G+ bacteria retain ______
A
Crystal violet
14
Q
G- bacteria retain ____
A
safranin
15
Q
Gram + aerobic cocci
A
Streptococcus
Enterococcus
Staphylococcus
16
Q
Gram + aerobic bacilli
A
Corynebacterium and listeria
17
Q
Gram + anaerobic cocci
A
Peptococcus
Peptostreptococcus
18
Q
Gram + anaerobic bacilli
A
Clostridium
Propionibacterium
19
Q
Gram - aerobic cocci
A
Moraxella
Neisseria
20
Q
Gram - aerobic bacilli
A
Pseudomonas
H. influenza
Campylobacter jejuni
E. Coli
Salmonella
Shigella
21
Q
Gram - anaerobic bacilli
A
Bacteroides
22
Q
Name some atypical bacteria
A
Chlamydia pneumoniae
Mycoplasma pneumoniae
Legionella pneumophilia
23
Q
Obtain _______ in acutely febrile patients
A
Blood cultures
24
Q
You should coincide cultures with __________
A
Fever spikes
25
Sensitivity results may take up to
72 hours
26
Sensitivity results are reported as
S (susceptible)
I (intermediate)
R (resistant)
27
Positive cultures don't always confirm _________
The presence of infection
28
Pneumonia associated with what pathogens
S. aureus (MRSA)
P. aeruginosa
Klebsiella
29
IV catheter site infection associated with what pathogens
S. aureus
S. epidermis
30
Susceptible
High-likelihood of clinical success
31
Intermediate
Questionable likelihood of clinical success
32
Resistant
High likelihood of therapeutic failure
33
What is an antibiogram?
Annual review that determines susceptibility profile for organisms, helps identify local and resistance patterns
34
In meningitis, _______ is an important determinant of the probable organism
Age
35
How can ABx fail?
Empiric ABx doesn’t cover the infecting organism
Concentration of ABx is too low at infection site
36
What host factors can render ABx less effective?
Immunosuppression (due to disease or drug drug therapy)
37
Intrinsic resistance
Naturally occurring
(Gram - pathogens intrinsically resistant to Vancomycin)
38
Four categories of acquired antimicrobial resistance
1. Alteration in target site
2. Reduction in Intracellular anti microbial exposure
3. Bypass of natural metabolic processes
4. Drug inactivation
39
Important questions to ask patients while considering ABx therapy
Allergies
Other medications (OTC and Rx)
40
What are the 3 classes of antibiotics?
Cell wall synthesis inhibitors
Nucleic acid synthesis inhibitors
Protein synthesis inhibitors
41
Cell wall synthesis inhibitors include
Beta-lactams
Glycopeptides
Lipopeptides
42
Beta-lactams mechanism of action
Inhibit cell wall synthesis by inhibiting penicillin binding proteins (PBPs)
Decreased integrity of peptidoglycan chain
43
4 classes of penicillins
Natural penicillins
Penicillinase-resistant
Aminopenicillins
Extended spectrum
44
Natural penicillins (V,G) coverage
Gram +
Staph - no
Strep - yes
Enterococcus (variable)
Gram-
Neisseria, syphilis
45
Common uses for natural penicillins
Pharyngitis
Erisipelas
Syphillis
46
More than 90% of staph produce _______, making them resistant to __________
Penicillinase, penicillins
47
Amino - penicillins coverage
Gram+
Strep, enterococcus
Gram -
Salmonella, shigella, E. Coli
48
Common uses for amino-penicillins
Upper respiratory infections
H. pylori
Enterococcal infections
Skin infections
UTIs
Community-acquired pneumonia
49
Penicillinase-resistant penicillins coverage
Gram +
Staph (but not MRSA)
Strep
50
Common uses for Penicillinase-resistant penicillins
B-lactamase producing staph
Cellulitis
Diabetic foot infections
Septic arthritis
Endocarditis
51
What is the #1 broad spectrum penicillin to use when we don’t know what to do?
Piperacillin/tazobactam
52
Extended-spectrum penicillins coverage
Gram +
Staph (not MRSA)
Strep
Enterococcus
Gram -
P. aeruginosa
53
Uses for extended spectrum penicillins
Nosocomial pneumonia
Intra-abdominal infections
Skin and soft tissue infections
54
Two predominant mechanisms of bacterial resistance to beta-lactam antibiotics
Production of antibiotic destroying enzymes (penicillinase, beta-lactamase, extended spectrum beta-lactamase/ESBL)
Development of altered target site
(Penicillin cannot bind to PBP, MRSA)
55
B-lactamase inhibitors
Clavulanate, sulbactam,tazobactam
56
What do B-lactamase inhibitors do?
Bind to and inactive b-lactamases, so antibiotics can do their job; have no particular antibiotic action themselves
57
Type 1 immediate hypersensitivity
IgE mediated
Causes urticaria, angioedema, bronchospasm
CV collapse
Anaphylaxis
58
4 options to work around patients Penicillin allergy
Perform penicillin allergy test (skin,oral challenge)
Prescribe a cephalosporin
Prescribe a non beta-lactam antibiotic
Perform a penicillin desensitization
59
Penicillin desensitization
Giving regular, small intervals in the ICU setting and monitoring reaction
Takes a lot of time, money, resources, and possibly dangerous
60
1st Gen cephalosporins
Cefazolin
Cephalexin
61
2nd Gen cephalosporins
Cefaclor, cefuroxime
62
3rd Gen cephalosporins
Ceftriaxone, cefpodozime
63
4th generation
Cefepime
64
5th Gen cephalosporins
Ceftaroline
65
What properties do cephalosporins share with penicillins?
MOA: target PBPs, destroy cell wall
Similarities in chemical structure: possibility for cross reactivity
Both considered first line for majority of infections (well tolerated, fairly cheap)
66
The later the generation of a Cephalosporin
The higher the gram - coverage
67
1st gen cephalosporin coverage
Gram+
Staph,Strep
Gram -
Proteus
E. coli
Klebsiella pneum.
68
Uses for 1st Gen cephalosporins
Mild skin/soft tissue infections
Pharyngitis
Oral treatment of Mild UTI
69
2nd Gen Cephalosporin coverage
Gram +
Staph, strep
Gram -
H. influenza
Gonorrhea
Proteus
E. coli
Klebsiella
70
2nd Gen cephalosporin uses
Sinusitis
Pharyngitis
Otitis media
71
1st and 2nd Gen cephalosporins generally work well against
MSSA or strep
72
3rd gen cephalosporins coverage
Gram +
Strep pneumoniae
Gram -
Enterbacteriaceae, H. influenza
73
3rd gen cephalosporin uses
CA pneumonia
Otitis media
Upper respiratory infection
74
4th gen cephalosporin coverage
Gram +
Strep
Staph
Gram -
Pseudomonas aeruginosa
75
4th gen cephalosporin uses
Meningitis
Nosocomial infections
Pneumonia
Pyelonephritis
76
3rd and 4th gen are most commonly used for hospitalized patients with concern for gram ________ pathogens
Negative
77
5th gen cephalosporins reserved for
Special cases with very resistant pathogens
78
The only drug included in the monobactam family is
Aztreonam
79
Aztreonam coverage
Gram -
Including P. aeruginosa
No gram +, atypical, or anaerobic coverage
Not available by mouth
80
Carbapenems are drug of choice for _______ producing organisms
ESBL
81
Carbapenems
Ertapenem
Imipenem
Meropenem
Doripenem
82
Carbapenems coverage
ESBL + K. pneumoniae and E. coli
Strep, MSSA, enterococcus, pseudomonas
No activity against MRSA or Atypicals
83
Ertapenem is an exception to the Carbapenems because it does not cover
Pseudomonas or enterococcus
84
Vancomycin is a
Glycopeptide antibiotic
85
Glycopeptide antibiotics coverage
Gram + bacteria
86
Glycopeptides inhibit cell wall synthesis by
Inhibiting NAG and NAM binding
87
Vancomycin is commonly used to treat
MRSA
88
Vanco coverage
Gram + (MRSA, strep, entercocci, c diff)
89
Potential for toxicity of vancomycin
Nephrotoxicity
Neutropenia, thrombocytopenia
90
What do you need to do in order to give Vanco?
Blood monitoring
Determine the patients renal function
91
Red man syndrome is side effect of which antibiotic?
Vancomycin
92
How to treat red man syndrome/Vancomycin flushing syndrome/(VIR) Vancomycin-infusion reaction
After stopping the vancomycin and letting rxn calm down, slow the infusion rate
Possible antihistamine administration
93
Televancin (Vibativ)
Lipoglycopeptide, simplified with once daily dosing
Black box warning: may cause abnormal fetal development
94
Oritavancin (Orbactiv)
IV single dose antibiotic
Indicated for ABSSSI (acute bacterial skin and skin structure infection)
95
Dalbanvancin
Once weekly antibiotic
96
Daptomycin
Lipopeptide
97
Daptomycin mechanism of action
Cyclic lipopeptide that inserts lipid tail into bacterial membrane resulting in depolarization of bacterial cell resulting in death (bactericidal)
98
Daptomycin coverage
MRSA and VRE
99
Potential for what toxicity with Daptomycin
Rhabdomyolosis (check CPK)
100
Name the protein synthesis inhibitors
Aminoglycosides
Tetracyclines
Macrolides
Linezolid
101
Tetracycline mechanism of action
Inhibits protein synthesis by binding to 30s ribosomal subunit
102
Tetracycline coverage
Gram +
S. pneumoniae
Strep pyogenes
CA-MRSA
Gram -
E. coli Klebsiella
Atypicals
Chlamydia (pneumonia/trachomatis),
mycoplasma pneumoniae
103
Use for tetracyclines
Respiratory infections, CA MRSA, SSTI, acne
Doxycycline: Chlamydia, Lyme
104
Consideration for tetracyclines
Separate food containing aluminum, mag, calcium, iron by 1-2 hrs
105
Tigecycline
Tetracycline
Higher mortality associated
FDA black box warning
106
With macrolides, we want to watch out for what two things?
QTc prolongation
CYP450 drug interactions
107
Macrolides MOA
Inhibit protein synthesis by binding to the 50s subunit
108
Macrolides are CYP _______ inhibitors
3A4
109
Which Macrolides are the “worst” for interactions/effects
(Worse to best)
Erythromycin
Clarithromycin
Azithromycin
110
Macrolides can give predisposition for what unstable ventricular arrhythmia
Torsades de pointes
111
Macrolides coverage
Gram +
Strep
Gram -
H influenza, gonorrhea
Atypicals
Mycoplasma pneumoniae
Chlamydia pneumoniae/trachomatis
112
Uses for Macrolides
Alternative to penicillin
CA-pneumonia
Azithromycin: Urethritis, MAC prophylaxis
113
Clindamycin type
Lincosamide antibiotic
114
Clindamycin MOA
Inhibits protein synthesis by binding to the 50s subunit
115
“Big” possible side effects of Clindamycin
C. diff
116
Clindamycin coverage
Gram +
Staph aureus (MSSA and CA-MRSA),strep, peptostrep
Gram -
Clostridium (not c. diff)
117
Clindamycin uses
PCN allergy
SSTI
CA-MRSA (risk for resistance)
118
Oxazolidinones
Linezolid
119
Linezolid coverage
Gram + MSSA/MRSA, strep, VRE
120
Linezolid MOA
Inhibits protein synthesis by preventing combining of 50s and 30s subunit
121
Risk of toxicity with Linezolid
Serotonin
122
Aminoglycosides
Gentamicin
123
The two styles of amino glycoside dosing are
1.High dose, extended interval dosing (good renal function)
2. Traditional
124
Aminoglycosides rarely used _______
Alone
125
Sulfonamides and trimethoprim MOA
Block nucleotide synthesis (specifically, folic acid synthesis which bacteria need to survive)
126
Bactrim coverage
Gram +
Staph
S. pneumoniae
Clostridium tetani
Gram -
E. coli, proteus, H. influenza
Atypicals:
-Chlamydia, trachomatis
127
Bactrim = frontline for
CA-MRSA
128
Fluoroquinolones
Quick development of resistance Absorption is reduced when (magnesium, iron etc) are given so space 2 hours apart
Ex. Ciprofloxacin and Moxifloxacin
129
Cipro MOA
Inhibits DNA replication by binding to DNA gyrase and topoisomerase IV
130
Ciprofloxacin coverage
Pseudomonas
131
Metronidazole good for treating
C-diff
132
Metronidazole MOA
Forms free radical toxic metabolites in the bacterial cell that damage DNA
133
Metronidazole, if taken with alcohol, can cause
“Hangover” reaction
134
Metronidazole coverage
Anaerobes and Protozoa
135
Enterococcus is never covered by
Cephalosporins
136
What conditions are low/medium dose topical steroids used for?
Eczema
Irritant dermatitis
Seborrhea
Atopic dermatitis
137
What conditions are high dose topical steroids used for?
Psoriasis, lichen planus, allergic contact dermatitis
138
Examples of low strength topical steroids
Alclometasone, hydrocortisone base or acetate, desonide
139
Examples of intermediate strength topical steroids
Fluticasone, hydrocortisone valerate, mometasone
140
Examples of high strength topical steroids
Amcinonide, halcinonide
141
Examples of very high strength topical steroids
Clobetasol, halobetasol
142
What’s a common ADR with topical steroid use?
Cutaneous atrophy - can have telangiectases and purpura, resolves after months
143
What are other/serious ADRs with topical steroid use?
Striae, acne, refractory rosacea, hypopigmentation, alopecia, glaucoma
144
What is an ADR associated with hormones with topical steroid use?
Adrenal suppression and iatrogenic cushing’s
~increased with children/dose/duration/higher potency
145
Treatment considerations for topical steroid use
1. Use low doses on areas with increased absorption
2. Occlusive dressings don’t use with high potency
3. Ointments have highest effects
4. For very high potency: don’t D/C abrupt but switch to lower strength, total dose should not exceed 50g/week, max TX duration should be 2-4 weeks
146
Rules of 3
Ultra high potency steroid: should NOT be used for more than 3 weeks
Low-high potency steroids should NOT be used for more than 3 months
147
Prescribing considerations with topical steroids
1. Hydration improves absorption (Ex. Apply post shower)
2. Most are once or twice daily
3. Fingertip method: half fingertip is 0.5 g and covers whole area of hand
148
Topical medications to treat psoriasis
1. Corticosteroids (1st line)
2. Vitamin D analogues (1st line)
3. Retinoids (1st line)
4. Calcineurin inhibitors
149
Vitamin D analogues
Photosensitivity
Increased calcium levels
Very irritating (causes stinging, burning, and peeling)
150
Retinoids
Photosensitivity
Pregnancy Category X
Very irritating (stinging, burning, and peeling)
151
Calcineurin inhibitors
Local stinging and burning but less than Tazarotene and Vit D analogs
*consider for facial or intertriginous psoriasis*
152
Oral psoriasis drugs (non-biologics)
1. Methotrexate
2. Cyclosporine
3. Oral retinoid (Soriatane)
4. Apremilast (Otezla)
153
Methotrexate
Contraindicated in pregnancy/lactation
Caution with hepatic dysfunction
154
Cyclosporine
Many drug interactions (with grapefruit for example)
Contraindicated in uncontrolled HTN,renal dysfunction,history of Malignancy, phototherapy
155
Oral retinoid (soriatane)
Contraindicated in pregnancy/lactation
Avoid pregnancy for 3 years after D/C
Causes significant dryness
156
Otezla
No serious ADR(no monitoring necessary), may cause weight loss, diarrhea, headache
157
Clinical pearls regarding oral meds for psoriasis
Need frequent lab monitoring/pregnancy tests
Concern for drug interactions
158
Biologic names for psoriasis treatment
Adalimmumab, Ustekinumab, Ixekizumab, Guselkumab, Risankizumab
-injections
-Expensive but very effective
Black box warnings~infections
159
Drugs to treat Urtcaria
Antihistamines
1. First generation (diphenhydramine, doxylamine): drowsiness
2. Second generation (cetirizine, levocetirizine): no/minimal drowsiness
160
Drugs for mild to moderate atopic dermatitis
1. Topical steroids: mainstay of therapy, prevent and/or treat flares
2. Topical Calcineurin inhibitors: alternative to steroids (tacrolimus, pimecrolimus)
3. Topical phosphodiesterase-4 inhibitors (Eucrisa): alternative to steroids
161
Risk vs Benefit of topical Calcineurin inhibitors
Benefits: Can use on any body area, no long term ADRs, no Tachyphylaxis, local ADRs are minimal
Risks: black box warning for malignancy (skin cancer and lymphoma) but relationship not firmly established
162
Monoclonal antibodies for atopic dermatitis
Injectable mab indicated for moderate to severe atopic Derm (Dupilumab/Dupixent)
163
Topical keratolytics for acne
Benzoyl peroxide: available OTC, oxidizes bacteria so no associated risk of resistance
164
Considerations with benzoyl peroxide
1. Formulation: Gels penetrate better than cream, look for “oil free”, alcohol base will increase ADRs
2. Strength: All concentrations are equally efficacious (but higher strength associated with more ADRs)
3. ADRs: skin irritation, contact derm, dryness, redness, peeling, stinging, photosensitive
165
Topical Retinoids
Adapalene
Tazarotene
Trifarotene
Tretinoin
166
Adapalene
Least irritating, available in combo with BPO, 0.1% get available OTC
167
Tazarotene
accumulates in upper dermis, also approved for psoriasis
168
Trifarotene
Selectively targets one type of retinoic receptor = theoretically more effective and less irritating, new and expensive
169
Topical retinoid info
Apply to dry skin to minimize irritation
170
Antimicrobial therapies for acne
1. Minocycline (Amzeeq foam): topically
2. Minocycline capsule/tab
3. Doxycycline capsule/tab
4. Sarecycline (seysara): Capsule/tab: used only for acne
171
Safety considerations for antimicrobial acne treatments
Should not use an antibiotic alone due to resistance, when considering combo use drugs with different MOA (not 2 abx)
172
Isotretinoin
Monitor LFTs, lipid panel, CBC
Pregnant patients pledge to use 2 forms of birth control along with monthly pregnancy tests
Suicide attempts?
173
OTC Pediculocides
1. Permethrin 1% (Nix): thought to have residual effect (newer shampoos may not)
2. Synergized pyrethrins shampoo (Rid): Always reapply
3. Ivermectin topical (sklice) may be good alternative if resistance is suspected
*Note: Nix and Rid are very similar chemically, so if resistant to one, probably resistant to both
174
Pediculocides (RX, non OTC)
Lindane
Benzyl Alcohol 5% (Ulesfia)
Malathion lotion
Spinosad suspension (Natroba)
Abametapir lotion (Xeglyze)
175
Benzyl alcohol 5% (Ulesfia)
Suffocation based therapy
Always reapply
176
Malathion lotion (Ovide)
Ovicidal
Wash it off after 8-10 hours
177
Spinosad suspension (Natroba)
High ovicidal activity
178
Scabicides
Permethrin 5% cream
Apply from neck to soles of feet
Wash off after 8-14 hours
Repeat in 48 hours
Adult dose is usually 30 g
Don’t dispense more than one tube per person (tube is 60 g)
179
Fungal infection tx
Treatment options: topical or PO depends on location
Topical usually sufficient for: tinea corporis, pedis, cruris, and versicolor
Oral tx necessary for tinea capitis and unguium
180
Fungal tx: imidazoles, triazoles
Clotrimazole (OTC)
Ketoconazole shampoo
Ketoconazole cream
Ketoconazole tablets
Fluconazole
181
Fungal tx: allylamines
Butenafine (OTC)
Terbinafine tablet (RX)
Terbinafine cream (OTC)
Ciclopirox cream (RX)
182
What is the Tx for a mild, purulent cellulitis infection
Incision and drainage, abx not required
183
Ruxolitinib and abrocitinib
JAK inhibitors used for atopic dermatitis
184
Closcoterone (Winlevi)
Anti androgen
For acne
New and expensive
185
Ciclopirox (loprox)
Onychomycosis
186
Cefaclor
2nd generation
187
Cefuroxime
2nd generation
Lyme disease
188
Cefdinir
3rd generation
189
Moxalactam
3rd generation
190
Which cephalosporins cover Bacteroides fragilis?
Cefoxitin and cefotetan
191
Which cephalosporins cover pseudomonas aeruginosa
Ceftazidime and cefepime
192
Azithromycin space with food reason
Increased absorption
193
Erythromycin space with food reason
Decreased absorption
194
C. Diff
Fidaxomicin and Vancomycin PO
195
Minocycline
Vestibular toxicity
196
Tetracycline food consideration
Empty stomach
197
Doxycycline food consideration
Take with food
198
Moxifloxacin vs cipro
Moxifloxacin is more likely to cause QT prolongation
199
What can you not use Daptomycin for?
Cannot use for meningitis: does not distribute into CNS
Cannot use for pneumonia: destroyed by pulmonary surfactant
200
Toxicity with Aminoglycosides
Ototoxicity and nephrotoxicity
201
Aminoglycosides and cystic fibrosis
Sometimes given as inhaled therapy
202
Nucleic Acid synthesis inhibitors
Sulfonamides, fluroquinolones, and metronidazole
203
Metronidazole side effects
Dry mouth, metallic taste
