Infectious Disease Flashcards
1
Q
What are the most common flora located in the upper respiratory? (4)
A
- Streptococci
- Staph. aureus (nose)
- Neisseria
- Haemophilus
2
Q
What are the most common flora located on the skin? (2)
A
- Staphylococcus
- Micrococcus
3
Q
What are the most common flora located in the mouth? (2)
A
- Streptococci
- Candida
4
Q
What are the most common flora located in the intestines? (6)
A
- Bacteroides
- Lactobacillus
- Clostridium
- Bifidobacterium
- Enterobacteriaceae
- Candida
5
Q
What is Minimum Inhibitory Concentration (MIC)? (2)
A
- The lowest concentration of antibiotic at which there is no visible growth (test tubes)
- Unique to each organism/drug pair
- CANNOT be compared on a culture and sensitivity
6
Q
What does MIC tell us? (2)
A
- Whether the bug is susceptible to an antibiotic (lab standards)
- How we need to structure our drug regimens
7
Q
What is time-dependent killing?
A
Duration of time the concentration of the drug is above the MIC
8
Q
What is concentration-dependent killing?
A
Ratio of the drug exposure to the MIC (AUC/MIC)
9
Q
Gram stain colors is driven by thickness of cell wall. what does Gram (+) and Gram (-) tell us?
A
- Gram (+) = thick cell wall
- Gram (-) = thin cell wall
10
Q
What antibiotic classes are classified as beta lactams? (3)
A
- Penicillins
- Cephalosporins (1st, 2nd, 3rd, 4th, 5th generation)
- Carbapenems
11
Q
What are the shared qualities of beta-lactams? (2)
A
- Destroyed by beta-lactamases
- No coverage of ‘atypical’ bugs
12
Q
Drugs that act on cell-walls typically have good gram-________ activity
A
positive
13
Q
Cloxacillin is effective against?
A
Staph species –> antistaphylococcal
14
Q
Amoxicillin/Ampicillin is effective against?
Intermediate against?
A
- Effect against Strep and Enterococcus
- Intermediate against Staph.
15
Q
Explain the mechanism of beta-lactam resistance (2)
A
- Resistance develops when antimicrobials are used inappropriately
- Bacteria can develop enzymes that inactivate beta-lactam drugs (enzymatic modification)
16
Q
How do beta-lactamases even work?
A
Disrupts the beta-lactam portion of the penicillin molecule
17
Q
Should know the difference between beta-lactamase vs. beta-lactamase inhibitors
A
- Beta-lactamase: enzymes that DESTROY beta-lactam rings
- The drug is inactivated and cannot kill the bacteria - Beta-lactamase inhibitors: prevent the beta-lactamase (enzyme) from working
- Allowing us to use beta-lactams again to treat an infection
18
Q
The addition of beta-lactamase inhibitor allows for what?
A
The addition of a beta-lactamase inhibitor will enhance the spectrum of activity (more gram-negative activity added because these tend to be the bugs that produce beta-lactamases)
19
Q
What are 2 beta-lactamase inhibitor antibiotics?
A
- Amoxicillin/clavulanate (Clavulin) (IV and oral) (clav portion)
- Piperacillin/tazobactam (Tazocin) (IV) [Hospital] (tazo portion)
20
Q
Compare amoxicillin spectrum vs. amoxi/clav spectrum of coverage
A
Amoxicillin:
1. Streptococci
2. Enterococci
3. Non-beta-lactamase producing organisms (E.coli, K.pneumoniae, H.influenzae)
Amoxi/Clav:
1. Streptococci
2. Enterococci
3. Staphylococcus (not MRSA)
4. Anaerobes
5. Some gram-negatives, beta-lactamase producing
21
Q
Compare gram-positive vs. gram negative activity of 1st generation cephalosporins
A
Gram-positive = +++
Gram-negative = +
22
Q
Compare gram-positive vs. gram negative activity of 2nd generation cephalosporins
A
Gram-positive = ++
Gram-negative = ++
23
Q
Compare gram-positive vs. gram negative activity of 3rd generation cephalosporins
A
Gram-positive = +
Gram-negative = +++
24
Q
Compare gram-positive vs. gram negative activity of 4th generation cephalosporins
A
Gram-positive = ++
Gram-negative = ++++
25
Compare gram-positive vs. gram negative activity of 5th generation cephalosporins
Gram-positive = +++
Gram-negative = +++
26
What are 2 1st gen cephalosporins to be aware of?
1. Cephalexin (oral)
2. Cefazolin (IV)
(Good gram-positive coverage (S. aureus, Strep --> skin infections)
27
What are 3 2nd gen cephalosporins to be aware of?
1. Cefuroxime (IV, oral)
2. Cefoxitin (IV)
3. Cefprozil (oral)
(Better gram-negative coverage but worse gram-positive coverage than 1st gen)
28
What are 2 3rd gen cephalosporins to be aware of?
1. Ceftriaxone (IV)
2. Cefixime (IV, oral)
(More gram-negative coverage but LESS gram-positive coverage than 1st and 2nd gen --> more broad spectrum)
29
4th and 5th gen are used for very niche purposes, just know the names of them. One each
4th gen = cefepime
5th gen = ceftaroline
30
What is the MOA of fluroquinolones? (3)
- Inhibits DNA topoisomerase
- These drugs work WITHIN the bacterial cell
- Can inhibit the growth of a variety of bacteria (both gram-positive and negative)
31
What area of the body are we thinking when we see ciprofloxacin?
Urinary bugs
- Enteric gram-negative aerobes (E. coli, Klebsiella)
- Pseudomonas (notable gram-negative bug)
32
What area of the body are we thinking when we see moxifloxacin/levofloxacin?
Respiratory
- Enteric gram-negatives
- S.pneumoniae --> ”respiratory FQ’s”, MSSA
- Pseudomonas (levofloxacin only)
- Anaerobes (moxifloxacin only)
33
Fluoroquinolones are rarely used as first-line why?
Often used in treatment failure or allergy. Broad-spectrum antibiotics
34
What is the MOA of tetracyclines?
Bind bacterial ribosome and inhibits protein synthesis
35
Tetracycline drugs end in?
-cycline
36
What bugs do tetracyclines cover? (3)
1. “Broad spectrum” coverage of gram-positive organisms
- Reduced because of increasing resistance
2. Good coverage of ‘atypicals’
3. Moderate coverage of MRSA, S. pneumoniae
- Does NOT provide good coverage of S. pyogenes (Group A Strep)
37
What is the MOA of macrolides/lincosamides?
Bind bacterial ribosome and inhibits protein synthesis
38
What are 3 macrolide drugs?
1. Clarithromycin (oral
2. Azithromycin (oral, IV)
3. Erythromycin (IV, no longer used orally)
39
Macrolides, broad or narrow spectrum?
Broad, BUT high resistance rates
(Also, just FYI, many drug interactions)
40
What bugs do macrolides cover? (2)
1. Good coverage of ‘atypicals’ and less-common respiratory bugs
2. Only moderate coverage of S. pneumoniae
- High rates of resistance in Saskatchewan --> limited use
41
What drug is a lincosamide?
Clindamycin
42
What does clindamycin cover? (2)
1. Good for: gram-positive anaerobes, S.pyogenes
- Useful in penicillin allergic patients (gram-positive coverage)
2. Moderate coverage for S.aureus, including MRSA
- Increasing resistance, not used as empiric MRSA therapy
43
What is clindamycin notable for?
Notable for high rates of antibiotic-associated diarrhea
- C.difficle diarrhea
44
What is the MOA of folate agonists?
Inhibits folate synthesis (required for DNA synthesis)
45
What drug is a folate antagonist?
Sulfamethoxazole/trimethoprim
46
What bugs does SMX/TMP cover? (2)
1. Staph. aureus including MRSA (resistance is growing)
2. Gram-negative bacilli (E.coli, K.pneumoniae) --> urinary tract infections
47
Why is SMX/TMP used less often as 1st-line therapy?
Due to unpredictable resistance. Culture is usually required
48
What is the MOA of nitrofurantoin?
- Toxic metabolite in bacteria
- Eliminated quickly by the kidneys --> move rapidly to bladder
49
What bugs does nitrofurantoin cover?
1. Used predominantly for urinary tract infections (UTIs)
2. Provides excellent coverage of common UTI bugs:
- Escherichia coli (75-95% of cases)
- Staphylococcus saprophyticus (5-10%)
- Streptococcus (1-2%)
50
What is the MOA of fosfomycin?
Inhibits bacterial wall synthesis
51
What is fosfomycin's main use?
UTI's
- Good coverage of E. coli (the dominant UTI bug)
52
What is the MOA of vancomycin?
Cell-wall inhibitor
53
What does vancomycin ONLY cover? (4)
1. Gram-positive coverage only
2. MRSA
3. Enterococcus
4. Staphylococcus
54
What are 3 ADEs of vancomycin to know?
1. Ototoxicity
2. Nephrotoxicity
3. Infusion-related reactions
55
What antibiotics cover MRSA? (11)
1. Ceftaroline
2. Tetracycline
3. Doxycycline
4. Minocycline
5. SMX/TMP
6. Clindamycin
7. Vancomycin
8. Daptomycin
9. Linezolid
10. Fosfomycin
11. Rifampin
56
What antibiotics are antipseudomonals? (12)
1. Piperacillin-tazobactam
2. Ceftazidime
3. Cefepime
4. Imipenem-cilastatin
5. Meropenem
6. Aztreonam
7. Ciprofloxacin
8. Levofloxacin
9. Gentamicin
10. Tobramycin
11. Amikacin
12. Colistimethate
57
What are 3 aminoglycoside drugs?
1. Gentamicin
2. Tobramycin
3. Amikacin
58
What do AMGs only cover? (4)
1. Gram-negative coverage
- Pseudomonas
- E. coli
- Klebsiella
59
What are 2 ADEs to be aware of for AMGs? (2)
1. Ototoxicity
2. Nephrotoxicity
60
What are 4 antivirals seen commonly in community?
1. Valacyclovir
2. Acyclovir
3. Oseltamivir
4. Nirmatrelvir-Ritonavir
61
What is valacyclovir used for? (5)
1. Herpes Simplex Virus (HSV)
2. (Cold Sores)
3. Can be used as treatment, or as prophylaxis
4. Varicella-zoster virus (VSV)
5. (Shingles)
- Used as treatment
62
What is acyclovir used for? (3)
1. Herpes Simplex Virus (HSV)
2. (Cold Sores)
3. Can be used as treatment
Note: also available as IV and oral forms
63
What is oseltamivir used for?
Influenza
64
What is Paxlovid used for?
COVID-19
65
What is the MOA of metronidazole?
DNA damage --> inhibits protein synthesis
- Activated by anaerobic bacteria and protozoa
66
What does metronidazole cover?
Think of it as the “antibiotic scavenger”
- Cover the organisms that other large classes of drugs don’t
- Good coverage of anaerobes, but poor coverage of anything aerobic
67
What are 2 types of antifungals?
1. Azoles
2. Polyenes
68
What is an important component for fungal cell membranes?
Ergosterol - an important target for antifungal drugs
69
What is the MOA of azoles?
Inhibit ergosterol production in cell membrane
70
What is a big ADE to aware of with any of the azoles?
QT prolongation
71
What is the MOA of nystatin (polyene)
Bind to ergosterol, leads to leakage of cell membrane
72
Which bacteria are considered the "atypicals"?
Examples?
Neither gram-positive or negative:
- Mycoplasma pneumoniae
- Chlamydia pneumoniae
- Legionella pneumoniae
73
What to know about nystatin absorption?
Very poorly absorbed - so limited systemic adverse effects/drug interactions
- QT prolongation unlikely to occur
74
How is nystatin dosed (administered)?
Swish and swallow/swish and spit
- Depends on site of infection (oral vs. esophageal involvement)
- Efficacy really related to contact time with area
75
What are the top 3 bugs that cause AOM?
What is 1 rarer bug?
1. Strep. pneumoniae (gram-positive)
2. Haemophilus influenzae (gram-negative)
3. Moraxella catarrhalis (gram-negative)
4. Rarer in children: S.aureus (gram-positive)
- But increasing in adults
76
How is (and isn't) AOM diagnosed?
1. Diagnosis is NOT POSSIBLE based on symptoms alone and there is NO confirmatory testing (i.e., no culture)
2. An otoscope must be used to diagnose AOM.
77
What are some signs and symptoms of AOM? (6)
1. Acute onset of symptoms
2. Ear pain
- Ear tugging, crying, irritability, altered sleep pattern
3. Middle ear fluid (seen with an otoscope)
4. Middle ear inflammation (seen with an otoscope)
5. Acute perforated TM
- Pain relief and purulent discharge from the ear
6. Hearing Loss
78
What are some "other" signs and symptoms of AOM? (5)
1. Fever
2. Nausea, vomiting, diarrhea
3. Feeling of ear fullness
4. Vertigo
5. Non-specific URTI symptoms
79
AOM symptoms may be __________ or __________
unilateral; bilateral
(Adult AOM is typically unilateral)
80
What 3 things are we looking for with an otoscope evaluation for AOM?
1. Moderately to severely bulging tympanic membrane
2. Pale yellow or white (sometimes redness)
3. Cloudy/opaque
81
Go through the stepwise approach for treating AOM? (3)
1. Treat the ear pain (regardless if antibiotic prescribed)
2. Consider watchful waiting
3. Select an antibiotic regimen
- 80% of AOM infections will spontaneously resolve without antibiotic treatment
82
What are the criteria for watchful waiting in AOM? (6)
1. 6 months of age and older
2. Mild illness (temperature < 39 C, responds to antipyretics, mild pain, feeding and drinking well, typical voiding, alert and calm)
3. Present within 48 hours of onset of ear pain
4. Have not had AOM in the previous month and AOM is not recurrent
5. No cochlear implants or other reported hearing impairment
6. No history of another condition that could make recovery more difficult (e.g., Down syndrome, craniofacial abnormalities, ear tubes)
83
Which AOM bug is least likely to resolve on its own?
S. pneumoniae
84
What is the standard dosing regimen of amoxicillin for AOM?
45-60 mg/kg/day divided TID
85
What is the high dose regimen of amoxicillin for AOM?
80-90 mg/kg/day divided BID or TID
86
High-dose regimen of amoxicillin in AOM should ONLY be used when?
For suspected resistant S. pneumoniae
87
What are some risk factors for resistant S. pneumoniae (4)?
1. Less than 2 years of age
2. Daycare
3. Any antibiotic exposure within 3 months
4. Under-vaccinated or unvaccinated
88
Alternative therapy for AOM might be used in patients who? (4)
1. Used amoxicillin in previous 30 days
2. Hx of AOM unresponsive to amoxicillin (treatment failure)
3. Concurrent purulent conjunctivitis (likely H.influenzae or M.catarhalis)
4. Immunocompromised
89
What are 2 decent options for alternative therapy in AOM?
1. 2nd gen cephalosporins (cefuroxine, cefprozil)
2. May require amoxicillin-clavulanate (broader spectrum, beta-lactamase inhibitor)
90
What are 2 potential reasons for AOM treatment failure?
1. Wrong drug
2. Dose too low
91
Amoxi/Clav has good coverage for (3)?
1. S. pneumoniae
2. H. influenzae
3. M. cattarhalis
92
The biggest ADE to remember for clavulanate is?
Diarrhea and stomach upset
93
For most AOM patients, how long is treatment (most of the time)?
5 days
94
What are the monitoring parameters for efficacy, safety, and adherence for AOM?
Efficacy
- Should see significant improvement within 2 to 3 days
- 50% of patients will have effusion remaining after treatment, and this may persist for weeks (up to 1 month in 50% of cases)
- It does not mean this is a treatment failure (OME)
Safety:
- Adverse effects of medication
Adherence:
- Is the child taking the medication?
- Is it being given? (caregiver)
95
What are some viral causes of CAP? (4)
1. Rhinovirus
2. Influenza
3. RSV
4. Covid-19
96
What are some bacterial causes of CAP? (3)
1. Streptococcus pneumoniae
2. Haemophilus influenzae
3. Mycoplasma pneumoniae
(Others - atypicals, S. aureus, GAS)
97
Early etiology of hosptial acquired pneumonia is <4 days - what bugs are the cause? (3)
Same as CAP
1. Streptococcus pneumoniae
2. Haemophilus influenzae
3. Mycoplasma pneumoniae
98
Late etiology of hosptial acquired pneumonia is >4 days - what bugs are the cause? (3)
1. Klebsiella
2. E. coli
3. Enterobacter
99
Later etiology of hosptial acquired pneumonia is <3 months - what bugs are the cause? (3)
1. Pseudomonas aeruginosa
2. Acinetobacter
3. S.aureus/MRSA
100
In pneumonia, the causative organism can be affected by certain factors/disease states, such as? (3)
1. Heart, lung disease (COPD), diabetes mellitus
2. Recent antibiotics – within the last 3 months
3. Aspiration, cystic fibrosis
101
What are the signs and symptoms of pneumonia? (7)
1. Up to 50% of patients report URTI
Abrupt onset of:
2. Fever (may be high [>39°C] or low grade)
3. Chills
4. Dyspnea
5. Cough (productive or non-productive)
6. Rust colored sputum or hemoptysis
7. Pleuritic chest pain (described as stabbing)
102
What are you looking for in a physical exam of pneumonia? (6)
1. Tachypnea
2. Tachycardia
3. Dullness to percussion
4. Diminished breath sounds over affected area
5. Inspiratory crackles
6. Low oxygen saturation (O2 sat)
103
What diagnostic imaging/laboratory things are we looking for in pneumonia? (2)
1. Chest x-ray
- Recommended in all adults to confirm suspected pneumonia
- Pulmonary infiltrates or consolidation
2. Bloodwork
- CBC, lytes, liver function, renal function
- Arterial blood gas (patients who have underlying resp condition)
- Sputum sample – may reveal PMNs and causative organism
- Blood culture – present to hospital
104
For a patient to be diagnosed with CAP, they must have: (3)
1. Infiltrate on CXR
2. At least one respiratory symptom:
- New or increased cough
- New or increased sputum
- Dyspnea
- Pleuritic chest pain
3. At least one other sign/symptom:
- Fever > 38 C
- Leukocytosis
- Hypoxia (O2 Sata < 90%)
105
What is the purpose of the CRB-65?
What do the scores tell you?
The scores being:
0
1-2
3+
Determines where they should receive treatment:
Score of 0 = outpatient
Score of 1-2 = consider hospital assessment +/- admission
Score of 3+ = hospital admission
106
What are some comorbidities or risk factors for resistant S. pneumoniae? (6)
1. Age ≥65 years
2. Cardiac, pulmonary, renal or hepatic failure
3. Smoking, alcoholism
4. Diabetes, malignancy
5. Malnutrition/acute weight loss
6. Immunosuppressive treatment (including high dose corticosteroid use)
107
What is the empiric treatment options for pneumonia? (5)
1. High dose amoxicillin - 1000mg PO TID
2. No atypical coverage, so need to add a second drug (macrolide) if you think the patient needs this
3. Doxycycline
4. Amoxi/Clav
5. Fluoroquinolones
108
For pneumonia, amoxicillin monotherapy is appropriate in which patients?
Healthy patients with no recent antibiotic use
109
What are 2 atypicals that can cause pneumonia?
1. Mycoplasma pneumoniae
2. Chlamydia pneumoniae
110
What to know about macrolide empiric therapy for pneumonia? (3)
1. Use in combination with beta-lactam for atypical coverage
2. S.pneumoniae coverage, but high resistance
- Monotherapy not recommended!
3. Azithromycin and clarithromycin
111
What to know about doxycycline empiric therapy for pneumonia? (3)
1. Not associated with S.pneumoniae resistance
2. Atypical and gram-negative coverage
3. May be used in patients with:
- beta-lactam allergy
- other comorbidities/risk factors for resistant S.pneumoniae
112
What to know about amoxi/clav empiric therapy for pneumonia? (3)
1. Patients with comorbidities (e.g., heart, lung disease (COPD), diabetes mellitus) are at increased risk of having:
- Gram-negative (H.influenzae, M. catarrhalis)
- Atypical (C.pneumoniae, Legionella) infections
- Along with S.pneumoniae
2. Broader-spectrum antibiotics are needed for additional organism coverage
- Beta-lactamase inhibitor, increased spectrum of activity for gram-negatives
3. No atypical coverage
113
What to know about using fluoroquinolones as empiric therapy for pneumonia? (4)
Bottom line: reserve respiratory fluoroquinolones (levofloxacin, moxifloxacin) for:
1. Treatment failure
2. Comorbidities with recent antibiotic use
3. Allergies
4. Documented highly drug-resistant bacteria
114
How long is duration of therapy for pneumonia?
- Traditionally thought to be 7-10 days, but recent RCTs showing that shorter duration is just as good
- Minimum of 3 days - typically 3-5 days (longer duration with more complex pneumonia)
115
What areas are classified as lower UTI? (2)
1. Bladder infection (cystitis)
2. Urethral infection
116
What areas are classified as upper UTI? (2)
1. Kidney infection
2. Ureter infection (ureteritis)
117
What is uncomplicated UTI defined as? (4)
1. No structural or functional abnormalities
2. Immunocompetent host
3. Female
4. No recent instrumentation/catheterization
118
What is complicated UTI defined as? (1)
Broad category that includes anyone who does not fall into "uncomplicated" categories
- Pregnancy is a whole other category by itself
119
What are the bugs that cause uncomplicated UTIs? (5)
1. E. coli (gram-) (80-90% of infections)
2. K. pneumoniae (gram-)
3. K. oxytoca (gram-)
4. Proteus spp. (gram-)
5. Enterococcus (gram+)
120
What are the bugs that cause complicated UTIs? (4)
1. E. coli (50% of infections)
2. Enterobacter spp. (gram-)
3. Pseudomonas aeruginosa (gram-)
4. Staph aureus (gram+)
121
What are some risk factors for developing a UTI? (9)
1. Age (older age)
2. Gender (female)
3. Recent sexual intercourse
4. Diabetes
5. Pregnancy
6. Renal disease
7. Structural or functional urologic abnormalities
- Indwelling catheter (~20% of patients will develop UTI)
- Neurologic dysfunction – stroke, diabetes, spinal cord injury
- Vesicoureteral reflux
- Incomplete bladder emptying
8. Urinary tract obstruction- including drugs like anticholinergics
9. Diaphragms/spermicides
122
What are the classic signs and symptoms of uncomplicated cystitis? (infection of the bladder, no upper UT involvement) (7)
1. Dysuria (painful or difficult urination)
2. Frequency (urinating often) / nocturia (nighttime urination)
3. Urgency (the feeling of needing to urinate)
4. Suprapubic pain (pain or discomfort in the lower abdomen)
5. Gross hematuria (blood in the urine)
6. Absence of vaginal discharge (presence could indicate vaginitis)
7. Patients have no systemic illness (fever, chills, vomiting)
123
What are classic signs and symptoms of pyelonephritis? (UTIs that extends into the kidneys) (4)
Think SYSTEMIC
1. Flank pain (pain in the low back)
2. Fever/chills
3. Nausea/Vomiting
4. Malaise
124
Older adults frequently do not experience "typical" UTI symptoms. What are some common symptoms seen in this population? (4)
1. Altered mental status/confusion
2. Change in eating habits
3. GI symptoms
4. Can still exhibit the other classic symptoms too
125
Urine dipstick tests are often done in which patients?
Women who have lower UTI symptoms and are uncomplicated
126
What are the two components of the urine dipstick test?
1. Leukocyte esterase test: enzyme in neutrophils
2. Nitrate reductase test: common urinary tract pathogens will convert nitrate to nitrite (E. coli will produce nitrites)
127
How long does it typically take for urinalysis (UA) results to come in?
Within a few hours
128
What is a urinalysis looking at? (2)
1. Microscopic examination
- Urine colour, clarity, specific gravity
- Presence of protein, glucose, RBCs, WBCs, bacteria and epithelial cells
2. Increased suspicion of infection if pyuria (> 10 WBC/mm3), bacteriuria (108 CFU/L)
- Without pyuria, unlikely to have UTI
129
Urine cultures usually take __-__ hours
24-48
130
Urine cultures review what things? (4)
1. Gram-stain
2. Quantity of bacteria (105-108 CFU/L indicative of UTI)
3. Identification of organism
4. Susceptibility
131
What is asymptomatic bacteriuria?
Patients have positive urine cultures but no symptoms
132
Who should always be treated if experiencing asymptomatic bacteriuria? (3)
1. Pregnant women
2. Children
3. Patients who will undergo urologic procedures
133
Who is asymptomatic bacteriuria common in? (2)
What to know about treatment for this population?
1. Elderly patients, like long-term care
2. Chronic catheter
3. NOT considered an infection NO ANTIBIOTICS ARE INDICATED
4. Bottom-line: Treating them is not beneficial and may cause harm.
134
What are 3 drugs for treating uncomplicated cystitis?
1. Nitrofurantoin - ineffective if CrCl <30mL/min
2. SMX/TMP
3. Fosfomycin
135
What is duration of therapy for uncomplicated cystitis?
3 days (SMX/TMP) to 5 days (Nitrofurantoin)
136
How is uncomplicated pyelonephritis treated (general)?
How long is duration?
1. May be treated as outpatient or inpatient
- Initial IV vs. oral therapy
- Sometimes IV therapy is preferred due to better bioavailability and response
2. Need to consider if the medication will penetrate the kidney
- Nitrofurantoin/Fosfomycin – do not use, does not provide adequate renal tissue concentrations
3. Duration: 10-14 days
137
What are the empiric IV therapies for uncomplicated pyelonephritis? (5)
1. Ceftriaxone (third-gen. cephalosporin, increased gram-negative coverage)
2. Ampicillin (Enterococcus coverage)
3. Amoxicillin-clavulanate
4. Ciprofloxacin (fluoroquinolone)
5. Aminoglycosides (tobramycin, gentamicin - excellent gram-negative coverage)
138
What are the empiric oral therapies for uncomplicated pyelonephritis? (3)
1. Amoxicillin-clavulanate
2. Cefixime (third-gen. cephalosporin)
3. Ciprofloxacin
139
What is the key point in using beta-lactams with E. coli infection?
Avoid as empiric monotherapy - culture and sensitivity must confirm susceptibility
140
What are 2 antibiotics for uncomplicated pyelonephritis that should not be used if there is no culture result available?
1. SMX/TMP
2. Cephalexin
141
What is duration of therapy for UTI in pregnancy?
3-7 days and follow-up culture to document eradication
142
What is first line treatment for UTI in pregnancy? (3)
1. Cephalexin 250-500mg QID x 7 days
2. Amoxicillin 500mg tid x 7 days
3. Nitrofurantoin 100mg bid x 5 days***
- Avoid ≥36-38 weeks GA
143
What is 2nd line treatment for UTI in pregnancy? (1)
TMP/SMX or TMP - avoid in first trimester and in last 6 weeks of pregnancy
144
What to know about UTIs in males? (4)
1. Traditionally considered “complicated” infections
2. May need to consider prostatitis (prostate infection)
3. Same antibiotics, as long as no prostate involvement
4. Longer duration of therapy (7 days)
145
What is the classic triad of symptoms of meningitis?
1. Fever
2. Neck stiffness
3. Altered mental status
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What are 2 physical tests for meningitis?
1. Brudzinski's Sign
2. Kernig's Sign
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How is bacterial meningitis diagnosed?
Diagnosis of bacterial meningitis requires CSF examination
- Composition
- Culture
148
Why is it hard to obtain CSF sample from neonates and children? (3)
1. Small volume
2. Contaminated sample with blood
3. Situations where LP is unsafe (e.g., elevated ICP, coagulation issues, hemodynamically unstable)
149
In a bacterial meningitis infection, should know how the following CSF parameters change:
1. WBC count
2. Protein
3. Glucose
4. CSF:serum glucose ratio
1. Elevated, predominantly neutrophils
2. Elevated
3. Reduced
4. <0.4
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What are 2 serum markers of inflammation that indicates a likely bacterial meningitis infection in children?
Elevated CRP and procalcitonin
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What to know about taking blood cultures to help diagnose meningitis? (3)
1. Very useful, especially if CSF cultures are negative or unavailable
- LP is contraindicated or low-yield sample
2. Remember: two separate sites should be sampled
- If possible, peripheral pokes (instead of drawn off a line)
3. If possible, cultures should be obtained BEFORE antibiotics are administered
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What are the most common bugs that cause meningitis in premature infants and neonates (<1 month of age)? (4)
1. E.coli
2. Group B Strep (S.agalactiae)
3. L.monocytogenes
4. Klebsiella species
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What are the most common bugs that cause meningitis in infants (> 1 month of age) and children (1-23 months old)? (3)
1. N.meningitidis
2. S.pneumoniae
3. H.influenzae
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What are the most common bugs that cause meningitis in 2-50 years old? (2)
1. N meningitidis
2. S. pneumoniae
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What are the most common types of bugs that cause meningitis resulting from surgery/trauma? (2)
1. Staph infection
2. Gram-negative bacilli
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What are the 2 drugs used in empiric therapy of meningitis?
1. Ceftriaxone (or cefotaxime)
2. Vancomycin
157
In meningitis treatment, antibiotics usually given with another drug (technically before the antibiotics) to help with treatment. What is it and why? (3)
1. Dexamethasone is an important medication in the treatment of meningitis
- Shown to decrease morbidity from long-term sequalae and mortality
2. Should be given prior to antibiotics
3. Can be discontinued depending on what bug is identified
- But should be started empirically in all patients with ?acute bacterial meningitis
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What are the most important host factors for meningitis treatment? (8)
1. Allergy
2. Age
3. Pregnancy
4. Pediatrics
5. Metabolic issues – some drugs cannot be used (e.g, G6PD and sulfonamides)
6. Organ dysfunction
7. Disease states
8. Patient adherence
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What is the best route of administration for meningitis treatment?
IV required for meningitis - 100% bioavailability
