Adults
Chlamydia pneumoniae is susceptible to tetracyclines, macrolides, and fluoroquinolones, all of which are equal first-line options. Most of the published treatment studies of pneumonia caused by C pneumoniae have relied entirely on diagnosis by serology; consequently, microbiologic efficacy could not be assessed. Anecdotal reports have suggested that prolonged courses, up to 3 weeks, of either tetracyclines or erythromycin may be needed to eradicate C pneumoniae from the nasopharynx of adults with flu-like illness and pharyngitis. Fluoroquinolones, including levofloxacin and moxifloxacin, are very effective in the treatment of C pneumoniae in adults.[14]Hammerschlag MR, Roblin PM. Microbiologic efficacy of levofloxacin for the treatment of community-acquired pneumonia due to Chlamydia pneumoniae. Antimicrob Agents Chemother. 2000 May;44(5):1409.
http://aac.asm.org/cgi/content/full/44/5/1409
http://www.ncbi.nlm.nih.gov/pubmed/10819727?tool=bestpractice.com
[15]Hammerschlag MR, Roblin PM. Microbiologic efficacy of moxifloxacin for the treatment of community-acquired pneumonia due to Chlamydia pneumoniae. Int J Antimicrob Agents. 2000 Jul;15(2):149-52.
http://www.ncbi.nlm.nih.gov/pubmed/10854812?tool=bestpractice.com
Tetracyclines and fluoroquinolones cannot be used in pregnant women. Treatment in this group should be with a macrolide (azithromycin, clarithromycin, or erythromycin). Fluoroquinolones are associated with serious, disabling, and potentially irreversible adverse effects including tendonitis, tendon rupture, arthralgia, neuropathies, and other musculoskeletal or nervous system effects.[16]European Medicines Agency. Quinolone- and fluoroquinolone-containing medicinal products. Mar 2019 [internet publication].
https://www.ema.europa.eu/en/medicines/human/referrals/quinolone-fluoroquinolone-containing-medicinal-products
[17]Food and Drug Administration. FDA Drug Safety Communication: FDA advises restricting fluoroquinolone antibiotic use for certain uncomplicated infections; warns about disabling side effects that can occur together. Mar 2018 [internet publication].
https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-fda-updates-warnings-oral-and-injectable-fluoroquinolone-antibiotics
The Food and Drug Administration (FDA) has also issued warnings about the increased risk of aortic dissection, significant hypoglycemia, and mental health adverse effects in patients taking fluoroquinolones.[18]Food and Drug Administration. FDA warns about increased risk of ruptures or tears in the aorta blood vessel with fluoroquinolone antibiotics in certain patients. Dec 2018 [internet publication].
https://www.fda.gov/drugs/drug-safety-and-availability/fda-warns-about-increased-risk-ruptures-or-tears-aorta-blood-vessel-fluoroquinolone-antibiotics
[19]Food and Drug Administration. FDA Drug Safety Communication: FDA reinforces safety information about serious low blood sugar levels and mental health side effects with fluoroquinolone antibiotics; requires label changes. Jul 2018 [internet publication]
https://www.fda.gov/drugs/drug-safety-and-availability/fda-reinforces-safety-information-about-serious-low-blood-sugar-levels-and-mental-health-side
Most patients will improve clinically despite persistence of the organism.[14]Hammerschlag MR, Roblin PM. Microbiologic efficacy of levofloxacin for the treatment of community-acquired pneumonia due to Chlamydia pneumoniae. Antimicrob Agents Chemother. 2000 May;44(5):1409.
http://aac.asm.org/cgi/content/full/44/5/1409
http://www.ncbi.nlm.nih.gov/pubmed/10819727?tool=bestpractice.com
[20]Block S, Hedrick J, Hammerschlag MR, et al. Mycoplasma pneumoniae and Chlamydia pneumoniae in community acquired pneumonia in children: comparative safety and efficacy of clarithromycin and erythromycin suspensions. Pediatr Infect Dis J. 1995 Jun;14(6):471-7.
http://www.ncbi.nlm.nih.gov/pubmed/7667050?tool=bestpractice.com
[21]Harris J-A, Kolokathis A, Campbell M, et al. Safety and efficacy of azithromycin in the treatment of community acquired pneumonia in children. Pediatr Infect Dis J. 1998 Oct;17(10):865-71.
http://www.ncbi.nlm.nih.gov/pubmed/9802626?tool=bestpractice.com
[22]Roblin PM, Hammerschlag MR. Microbiologic efficacy of azithro-mycin and susceptibility to azithromycin of isolates of Chlamydia pneumoniae from adults and children with community acquired pneumonia. Antimicrob Agents Chemother. 1998 Jan;42(1):194-6.
http://aac.asm.org/cgi/content/full/42/1/194
http://www.ncbi.nlm.nih.gov/pubmed/9449287?tool=bestpractice.com
Persistence does not appear to be secondary to the development of antibiotic resistance.[14]Hammerschlag MR, Roblin PM. Microbiologic efficacy of levofloxacin for the treatment of community-acquired pneumonia due to Chlamydia pneumoniae. Antimicrob Agents Chemother. 2000 May;44(5):1409.
http://aac.asm.org/cgi/content/full/44/5/1409
http://www.ncbi.nlm.nih.gov/pubmed/10819727?tool=bestpractice.com
[15]Hammerschlag MR, Roblin PM. Microbiologic efficacy of moxifloxacin for the treatment of community-acquired pneumonia due to Chlamydia pneumoniae. Int J Antimicrob Agents. 2000 Jul;15(2):149-52.
http://www.ncbi.nlm.nih.gov/pubmed/10854812?tool=bestpractice.com
[22]Roblin PM, Hammerschlag MR. Microbiologic efficacy of azithro-mycin and susceptibility to azithromycin of isolates of Chlamydia pneumoniae from adults and children with community acquired pneumonia. Antimicrob Agents Chemother. 1998 Jan;42(1):194-6.
http://aac.asm.org/cgi/content/full/42/1/194
http://www.ncbi.nlm.nih.gov/pubmed/9449287?tool=bestpractice.com
Children
Recommended treatment is with macrolides.[20]Block S, Hedrick J, Hammerschlag MR, et al. Mycoplasma pneumoniae and Chlamydia pneumoniae in community acquired pneumonia in children: comparative safety and efficacy of clarithromycin and erythromycin suspensions. Pediatr Infect Dis J. 1995 Jun;14(6):471-7.
http://www.ncbi.nlm.nih.gov/pubmed/7667050?tool=bestpractice.com
[21]Harris J-A, Kolokathis A, Campbell M, et al. Safety and efficacy of azithromycin in the treatment of community acquired pneumonia in children. Pediatr Infect Dis J. 1998 Oct;17(10):865-71.
http://www.ncbi.nlm.nih.gov/pubmed/9802626?tool=bestpractice.com