ASK DIS: Management of CAP in Pregnancy

Pathogens include Streptococcus pneumoniae, Haemophilus influenzae, mycoplasma, chlamydia, viruses, legionella, Staphylococcus aureus, and gram negative bacilli
Since gram negative bacilli tend to cause pneumonia in patients with underlying morbidities, it is uncommon in young, otherwise healthy, pregnant women.

Choice of Antibiotics

For pregnant women with community-acquired pneumonia and no features of severe disease, we suggest combination therapy with an antipneumococcal beta-lactam (ceftriaxone, cefotaxime, ampicillin-sulbactam) plus azithromycin, given the >25 percent rate of macrolide resistance in all regions of the United States and in certain other countries.
Patients with past allergic reactions to cephalosporins can be treated with clindamycin plus aztreonam, unless they have severe pneumonia.
For patients with severe pneumonia and a past allergic reaction to cephalosporins, we recommend vancomycin (for coverage for MRSA and drug-resistant S. pneumoniae) plus azithromycin plus aztreonam.

Outpatient treatment

Previously healthy/no risk factors for drug-resistant S. pneumoniae (DRSP) infection:

A macrolide (azithromycin, clarithromycin, or erythromycin) (strong recommendation; level I evidence)

Presence of comorbidities, such as 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:

A respiratory fluoroquinolone (moxifloxacin, gemifloxacin, or levofloxacin [750 mg]) (strong recommendation; level I evidence)
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)

Inpatient, non-ICU treatment

A respiratory fluoroquinolone (strong recommendation; level I evidence).
A b-lactam plus a macrolide (strong recommendation; level I evidence) (Preferred b-lactam agents include cefotaxime, ceftriaxone, and ampicillin;
ertapenem for selected patients;
doxycycline [level III evidence] as an alternative to the macrolide.
A respiratory fluoroquinolone should be used for penicillin-allergic patients.)

Inpatient, ICU treatment

A b-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam) plus either azithromycin (level II evidence) or a fluoroquinolone (level I evidence) (strong recommendation)

(For penicillin-allergic patients, a respiratory fluoroquinolone and aztreonam are recommended).

For Pseudomonas infection, use an antipneumococcal, antipseudomonal b-lactam (piperacillin-tazobactam, cefepime, imipenem, or meropenem) plus either ciprofloxacin or levofloxacin (750-mg dose)
Or
The above b-lactam plus an aminoglycoside and azithromycin.
Or
The above b-lactam plus an aminoglycoside and an antipneumococcal fluoroquinolone (for penicillin-allergic patients, substitute aztreonam for the above b-lactam). (Moderate recommendation; level III evidence).
For community-acquired methicillin-resistant Staphylococcus aureus infection, add vancomycin or linezolid. (Moderate recommendation; level III evidence).

Antibiotics to be Avoided

Tetracyclines (including doxycycline and minocycline)

Tigecycline

Clarithromycin

Fluoroquinolones*

Erythromycin estolate^¶

Chloramphenicol

Kanamycin, streptomyci

Antibiotics to be avoided in pregnancy include doxycycline, clarithromycin, and the fluoroquinolones
clarithromycin has produced adverse pregnancy outcome in animal studies at low-order multiples of human doses; human experience is very limited and has not suggested an increase in congenital anomalies in exposed pregnancies, but an increased risk of miscarriage has been reported, possibly related to the underlying disease
The fluoroquinolones are avoided during pregnancy because of concerns about fetal arthropathy and malformations based on animal studies. However, safe use in pregnancy has been reported, suggesting that they may be used if alternatives are less safe or effective

References:

ASK DIS