Azithromycin: spawn of Satan or just evil incarnate?

All prescribers are certainly aware of (and hopefully accept the reality of) increasing antibiotic resistance. While guidelines continue to be released encouraging less antibiotic use for sinusitis, bronchitis, and otitis media, there also continues to be use or, more correctly, overuse of these powerful but potentially dangerous drugs.

One of the most overused antibiotics is azithromycin, which I will address from the pediatric perspective in this post. Sure, it’s convenient, easy to dose, and requires a shorter course. But most of the time it’s either too broad-spectrum or, worse, not an adequate choice. A 2011 study In Pediatrics using visit and prescribing data from 2006-8 found:

“Antibiotics were prescribed during 21% of pediatric ambulatory visits; 50% were broad-spectrum, most commonly macrolides… Twenty-three percent of the visits in which antibiotics were prescribed were for respiratory conditions for which antibiotics are not clearly indicated.”

The authors concluded:

“Broad-spectrum antibiotic prescribing in ambulatory pediatrics is extremely common and frequently inappropriate.”

In 2011, azithromycin became the most commonly prescribed antibiotic in the US across all ages. For the same year, it was #2 among children. 2014 prescribing data from PHC shows it is the second most prescribed antibiotic, at 12.5% of all antibiotics, compared to amoxicillin at 20.4%.

Guidelines from the AAP Infectious Disease Committee (Principles of Judicious Antibiotic Prescribing for Bacterial Upper Respiratory Tract Infections in Pediatrics) state very clearly:

“Azithromycin is not a first line antibiotic for any pediatric URI [emphasis added] and is the antibiotic most likely to be used inappropriately (inadequate coverage for the most common pathogens causing AOM and sinusitis).”

The Canadian Pediatric Society published their own guidelines in 2013 that classified azithromycin as “Do Not Use” for pneumonia, otitis, and pharyngitis. In addition to being ineffective against the two major organisms that cause otitis (see above), its prolonged half-life leads to more rapid development of bacterial resistance.

Infectious diseases experts in New Zealand recommend azithromycin only be used in the following situations:

  • First-line indications: pertussis in children, chlamydia, gonorrhea (for treatment of presumed co-infection with chlamydia), acute non-specific urethritis
  • Second-line indications: pelvic inflammatory disease as an alternative to doxycycline when chlamydia is present, pertussis in adults when erythromycin is unable to be tolerated

Macrolide-resistant bacteria are also a growing problem. Children treated with azithromycin are more likely to have nasal carriage of resistant pneumococci. A 2013 Canadian study showed a 12% macrolide resistance rate in pneumococcus in Ontario. Some areas of Asia have 90% or greater resistance for both Mycoplasma pneumoniae and Strep. pneumococcus. A South Korean study showed that macrolide-resistant M. pneumoniae grew from 0% in 2000 to 63% by 2011.

In regard to treatment of m. pneumoniae in children, a systematic review published in June 2014 in Pediatrics, “found insufficient evidence to support or refute antibiotic use in CA-LRTI [community-acquired lower respiratory tract infection] secondary to M. pneumoniae. This suggests that macrolide use in CA-LRTI could represent an area of opportunity for reducing antibiotic use, which could have a significant impact on health care costs and the development of antimicrobial resistance.”

While this post focuses on the pediatric population, data and recommendations in the adult world are similar. So the next time you are considering treating that OM or sinusitis, don’t “reach” for the Z-pack!

Jeff Ribordy, MD