A Simple Community-Acquired Pneumonia? -- Appropriate Antibiotic Choice in the Era of Strep Pneumo Resistance
Clinical Scenario:
You are taking care of a middle-aged female who presents to the ER from home with fevers/chills, shortness of breath, and cough that has gotten progressively worse over the last two days. She has not been in the hospital within the last 3 months and does not have other HCAP risk factors. You decide to get a CXR which identifies a patchy left lower lobe airspace opacity and tiny left pleural effusion consistent with pneumonia.
You are taking care of a middle-aged female who presents to the ER from home with fevers/chills, shortness of breath, and cough that has gotten progressively worse over the last two days. She has not been in the hospital within the last 3 months and does not have other HCAP risk factors. You decide to get a CXR which identifies a patchy left lower lobe airspace opacity and tiny left pleural effusion consistent with pneumonia.
Clinical Question:
With the increasing resistance of Strep pneumo to macrolides, should we consider changing outpatient CAP empiric treatment to a fluoroquinolone? Keep in mind, that here in Saint Louis, Strep pneumo is sensitive to erythromycin 54% of the time at BJH and 43% of the time at SLCH according to current antibiogram data.
With the increasing resistance of Strep pneumo to macrolides, should we consider changing outpatient CAP empiric treatment to a fluoroquinolone? Keep in mind, that here in Saint Louis, Strep pneumo is sensitive to erythromycin 54% of the time at BJH and 43% of the time at SLCH according to current antibiogram data.
Literature Review:
In
2007, the Infectious Disease Society of America (IDSA) and the American
Thoracic Society (ATS) convened a joint committee to develop a unified
stance community acquired pneumonia
(CAP) treatment. Their recommendations follow:
1.
Patients that are previously healthy with no risk factors for Drug
Resistant Strep pneumo (DRSP) pneumonia can be treated with:
a. A macrolide (azithromycin, clarithromycin, or erythromycin) (strong recommendation; level I evidence)
b. Doxycycline (weak recommendation; level III evidence)
2. HOWEVER, in regions with a high rate (greater than 25%) of infection
with high-level (MIC, >16 mg/mL) macrolide-resistant S. pneumoniae, one should consider the use of alternative agents for any patient, including
those without comorbidities. (Moderate recommendation; level III evidence.)
3.
Presence of comorbidities (including, chronic heart, lung, liver, or
renal disease; diabetes mellitus; alcoholism; malignancies; asplenia;
immunosuppressing conditions
or use of immunosuppressing drugs; use of antimicrobials within the
previous 3 months [in which case an alternative from a different class
should be selected]; or other risks for DRSP infection) should prompt
the selection of a regimen listed below
a.
A respiratory fluoroquinolone (moxifloxacin, gemifloxacin, or
levofloxacin [750 mg]) (strong recommendation; level I evidence)
b. A b-lactam plus a
macrolide (strong
recommendation; level I evidence) (High-dose amoxicillin [e.g., 1 g 3
times daily] or amoxicillin-clavulanate [2 g 2 times daily] is
preferred; alternatives include ceftriaxone, cefpodoxime, and cefuroxime
[500 mg 2 times daily]; doxycycline [level II evidence]
is an alternative to the macrolide.)
However,
when the types of antibiotics prescribed were tallied, appropriate
therapy (concordant with IDSA/ATS guideline) was prescribed only 9% of
the time in the DRSP risk factor group
versus 87% of the time in the no DRSP risk factor group. This was
statistically different with a p < 0.0001. This means that 91% of
patients with risk factors for DRSP were not being treated with suggested
antibiotic regimens.
Clinical Takehome:
- When selecting an outpatient antibiotic regimen for Community Acquired Pneumonia (CAP), one must take into account DRSP risk factors AND regional Strep pneumo sensitivities.
- Macrolide monotherapy is not sufficient CAP treatment for a subset of patients.
- Unfortunately, respiratory fluroquinolones are much more expensive than the traditional Z-pak. However, an acceptable alternative is azithromycin with amoxicillin.
- When selecting an outpatient antibiotic regimen for Community Acquired Pneumonia (CAP), one must take into account DRSP risk factors AND regional Strep pneumo sensitivities.
- Macrolide monotherapy is not sufficient CAP treatment for a subset of patients.
- Unfortunately, respiratory fluroquinolones are much more expensive than the traditional Z-pak. However, an acceptable alternative is azithromycin with amoxicillin.
References:
1) Mandell
LA, Wunderink
RG, Anzueto
A, Bartlett
JG, Campbell
GD, Dean
NC, Dowell
SF, File
TM Jr, Musher
DM, Niederman
MS, Torres
A, Whitney
CG; Infectious
Diseases Society of America; American
Thoracic Society.
Infectious Diseases Society of America/American Thoracic Society
consensus guidelines on the management of community-acquired pneumonia
in adults. Clin Infect Dis. 2007 Mar 1;44 Suppl 2:S27-72.
2) Jenkins TC, Sakai J, Knepper BC, Swartwood CJ, Haukoos JS, Long JA, Price CS, Burman WJ. Risk factors for drug-resistant Streptococcus pneumoniae and antibiotic prescribing practices in outpatient community-acquired pneumonia. Acad Emerg Med. 2012 Jun;19(6):703-6.
2) Jenkins TC, Sakai J, Knepper BC, Swartwood CJ, Haukoos JS, Long JA, Price CS, Burman WJ. Risk factors for drug-resistant Streptococcus pneumoniae and antibiotic prescribing practices in outpatient community-acquired pneumonia. Acad Emerg Med. 2012 Jun;19(6):703-6.
Contributed by Daniel Kolinsky, PGY-2
Faculty Reviewed by Dr. Stephen Liang