9 - LRTI (Pneumonia) Flashcards
1
Q
What are the clinical signs and symptoms of pneumonia?
A
- Acute respiratory and systemic signs and sx; infection and inflammation of pulmonary parenchyma
- Cough, sputum production, crackles, consolidation, tachypnea > 24, dyspnea, hypoxia, hemoptysis, pleural pain
- Fever, chills, tachycardia > 100, leukocytosis
2
Q
How is community-acquired pneumonia diagnosed?
A
- Clinical signs and sx
- Lung infiltrate on x-ray
3
Q
Why is the culture yield of sputum poor? What can be done to improve this?
A
- B/c of poor quality sampling and fastidious or slow-growing pathogens
- Improved yield in endothelial lining fluid (ELF) obtained by bronchoalveolar lavage (BAL)
4
Q
What are the most common pathogens associated w/ CAP and pathogen-specific risk factors?
A
- Viral predisposes to secondary bacterial pneumonia
- Strep pneumonia - COPD, CV or renal disease, asplenic, diabetes, immunocompromised
- Mycoplasma pneumoniae - adolescents, young and elderly adults
5
Q
What are some less common pathogens associated w/ CAP and pathogen-specific risk factors?
A
- Gram neg bacilli (H. influenzae, moraxella catarrhalis) – COPD, smoking; (klebisella pneumoniae, E. coli, enterobacter) – COPD, smoking, diabetes, alcoholism
- P. aeruginosa – cystic fibrosis, COPD, immunocompromised
- Staph aureus
- Anaerobes - aspiration, neurological disease
6
Q
Do meropenem and amox-clav have coverage against mycoplasma?
A
No, b/c these drugs work against the cell wall, which mycoplasma don’t have; so drugs that work against ribosomes will have coverage over mycoplasma
7
Q
What are some characteristics of pneumonia associated w/ mycoplasma pneumoniae?
A
- Peak incidence in older children, adolescents, young adults, and elderly
- Incubation 2-3 weeks, associated w/ pharyngitis, tracheobronchitis, pneumonia
- Serology using IgM enzyme immunoassay; respiratory sample PCR
- Gradual onset fever, headache, GI sx, malaise, arthralgia, myalgia, rash, cardiac syndromes for 1-2 weeks, followed by non-productive cough for 3-4 weeks
8
Q
What are some characteristics of pneumonia associated w/ legionella pneumophila?
A
- Ubiquitous in water and soil, outbreaks and sporadic cases w/ peak from June to Octboer, associated w/ air ventilation systems
- Rapidly progressive pneumonia w/ multi-system involvement including fever, malaise, arthralgia, pleuritic pain, CNS & GI sx
9
Q
What are the considerations for antimicrobial therapy in CAP?
A
- Suspected pathogens and risk for resistance
- Severity of illness; co-morbidities influencing likelihood of pathogen or clinical response
- Availability, formulary, cost
- Potential CI’s, drug interactions & adverse effects
- Appropriate dose (weight, renal and hepatic function)
10
Q
Antimicrobial options for empirical tx of ambulatory, mild-moderate CAP? Is it given PO or IV?
A
- PO
- Amox (+/- macro or doxy) for moderate illness, or if not improving w/in 3 days of amox therapy
- Macrolide (concerns regarding resistance)
- Doxy (less clinical data than alternatives)
11
Q
Antimicrobial options for empirical tx of ambulatory, mild-moderate CAP w/ risk factors for resistance or poor prognosis? Is it given PO or IV?
A
- PO
- Amox-clav (+/- macro or doxy) - add if not improving w/in 3 days or initial therapy
- Cefprozil/ cefuroxime (+/- macro or doxy)
- Levo/ moxi - restrict to more severe illness, tx failure, or serious beta-lactam allergy
12
Q
Antimicrobial options for empirical tx of severe CAP? Is it given po or IV?
A
- IV
- Levo/ moxi
- Cefotaxime/ ceftriaxone + azithromycin
- Cefotaxime/ ceftriaxone + levo/ moxi – seriously ill, ICU admission
13
Q
Adult dosing of amoxicillin for CAP
A
1 g q8h (high dose)
14
Q
Adult dosing of amox-clav for CAP
A
500/125 mg q8h or 875/125 mg q12h
15
Q
Adult dosing of macrolides for CAP
A
- Erythromycin 500 mg q6h
- Clarithromycin 500 mg q12h or 1 g ER q24h
- Azithromycin normal dosing
16
Q
Adult dosing of doxycycline for CAP
A
100 mg PO q12h
17
Q
Adult dosing of cefprozil or cefuroxime for CAP
A
500 mg q12h
18
Q
Adult dosing of ceftriaxone or cefotaxime for CAP
A
- Ceftriaxone = 1 g q24h
- Cefotaxime = 1-2 g q8h
19
Q
Adult dosing of fluoroquinolones for CAP
A
- Levo = 500-750 mg q24h
- Moxi = 400 mg q24h
20
Q
What is the typical response for antimicrobial tx of CAP?
A
- Clinical improvement w/in 2-3 days
- Complete resolution in 10-14 days
21
Q
What is the duration of tx for CAP?
A
5-7 days based on clinical response and resolution
22
Q
What are some risk factors for LRTI?
A
- Elderly
- COPD, congestive heart failure, end-stage renal disease, diabetes
- Smoking, alcoholism
- Cerebrovascular or neurological disease, immunocompromised
23
Q
What are the severity scores of LRTIs?
A
- PSI (pneumonia severity index)
- CURB-65 – new onset confusion, plasma urea > 7.1 mmol/L, RR > 30, BP < 90/60, or age > 65 years
- Score of 3 or higher = should be admitted to hospital and treated IV
24
Q
What are the monitoring parameters for treating pneumonia?
A
- Cough = improved or absent w/in 2-7 days
- HR, RR, and temp = normal w/in 2-3 days
- WBC = normal w/in 5-7 days
- Chest x-ray = repeat if deterioration; normal in over 6 weeks
25
What should be considered for PO step-down antimicrobial therapy for pneumonia?
- Clinical improvement and hemodynamically stable
- Afebrile x 24-48 h
- Agent w/ appropriate spectrum, reliable bioavailability, adequate concentrations, and good tolerability
26
Antimicrobial options for pathogen-directed tx for S. pneumoniae CAP?
- PO = amox [levo/ moxi or linezolid]
- IV = Pen G [cefotax/ ceftriax or vanco]
- Combination IV therapy w/ beta-lactam plus macrolide or aminoglycoside suggested for moderate-severe pneumococcal pneumonia
27
Antimicrobial options for pathogen-directed tx for M. pneumoniae CAP?
PO/IV = macrolide, doxycycline, or levo/ moxi
28
Antimicrobial options for pathogen-directed tx for H. influenzae CAP?
- PO = amox or amox-clav [cefprozil/ cefuroxime or levo/ moxi/ cipro]
- IV = cefuroxime or cefotaxime/ ceftriaxone [levo/ moxi/ cipro]
29
What do macrolides inhibit?
CYP 3A4 and the enzyme P-gP
30
Interaction of macrolides w/ statins
Lovastatin and simvastatin are absolutely contraindicated w/ azithro and clarithro
31
Interaction of macrolides w/ cyclosporine
- Interaction is variable from pt to pt
- Tacrolimus more susceptible to interaction than cyclosporine
- CI
32
Interaction of macrolides w/ lorazepam
- Not affected by clarithro
- Medazolam or triazolam are affected by clarithro
- CI
33
Interaction of macrolides w/ diltiazem
- Applies to all calcium channel blockers
- Significant interaction w/ clarithro (increases levels of CCB => hypotension and bradycardia)
- CI
34
Interaction of macrolides w/ warfarin
- Broad spectrum antibiotics get rid of gut flora which produce vitamin K, so vitamin K is reduced
- Recommendation to monitor warfarin
35
Interaction of macrolides w/ digoxin
Absorption can be increased by antibiotic b/c antibiotics inhibit P-gP
36
Interaction of macrolides w/ colchicine
- Increases absorption b/c of inhibition of CYP 3A4 and P-gP
- Life-threatening b/c is an anti-mitotic drug, so toxicity will cause WBC to dramatically decrease
- Azithro has about 1/4 of the effect of clarithro
- CI
37
Interaction of quinolone w/ insulin
Quinolones have metabolic effect on glucose, so can cause hypo or hyperglycemia
38
Interaction of quinolone w/ Maalox (Al, Mg, Fe, sucralfate)?
- Affects absorption
- Most prevalent w/ cipro than levo/ moxi
- Calcium tends to be less affected
39
What effect does quinolones have on the heart?
- Variable QT prolongation (moxi > levo/ cipro) => can cause Torsade de Pointes, ventricular arrhythmias, or sudden death
- More often in px w/ pre-existing QT prolongation, underlying pro-arrhythmic conditions, class 3 anti-arrhythmics, tricyclic antidepressants, anti-psychotics, and other antibiotics
40
What are some risk factors for nosocomial pneumonia (hospital acquired)?
- Hospitalization > 3 days, surgery, ICU admission (mechanical ventilation)
- Risk factors for aspiration (immobility, supine positioning, NG tubes)
- Antacids or gastric acid suppression w/ H2 antagonists or PPIs
41
What are the most likely pathogens in NP?
- Strep pneumoniae (particularly w/in 3 days of admission)
- Staph aureus including MRSA
- K. pneumoniae, E. coli, enterobacter spp
- P. aeruginosa, acinetobacter, stenotrophomonas maltophila
42
What is the difference between nosocomial pathogens and pathogens that are community-acquired?
- Nosocomial pathogens associated w/ higher rates of resistance leading to delays in appropriate therapy and worse prognosis
- Nosocomial pathogens more common in px undergoing chronic dialysis, from long-term care facilities, or hospitalized w/in 3 months
43
What are the antimicrobial options for NP that has early onset w/in 3 days of admission? Is it PO or IV?
- IV
- Ceftriaxone/ cefotaxime
- [Levo/ moxi] -- allergy
44
What are the antimicrobial options for NP that occurred w/in 3 days of admission or has risk factors for resistant pathogens? Is it PO or IV?
- IV
- Ceftazadime + vanco (preferred choice b/c least broad)
- Pip-tazo +/- vanco
- Meropenem +/- vanco
- [Cipro/ levo + vanco] - allergy
- [AG + vanco] - allergy and FQ resistance
45
What are the issues regarding antimicrobial activity in the lungs?
- Blood-bronchus barrier penetration
- Site of infection
- Optimal dosing based on PK-PD to optimize efficacy, minimize adverse effects, and limit resistance
46
What are the IV antimicrobial options for pathogen-directed MSSA NP?
- Clox or cefazolin
- [Vanco or linezolid]
- Not dapto!
47
What are the IV antimicrobial options for pathogen-directed MRSA NP?
- Vancomycin
| - [Linezolid]
48
What are the IV antimicrobial options for pathogen-directed enterobacteria NP?
- Cefotaxime/ ceftriaxone
- Cipro/ levo/ moxi
- [Pip-tazo or meropenem/ ertapenem] - as per susceptibilities
49
What are the IV antimicrobial options for pathogen-directed P. aeruginosa NP?
- Ceftazadime
- Pip-tazo
- Meropenem
- +/- gent/ tobra or cipro/ levo
50
What is the typical duration of therapy for HAP?
7 days based on pt, clinical status, pathogen, and response to therapy
