No Statistical Difference for Doxycycline, Azithromycin in CAP Outcomes

The ceftriaxone + doxycycline regimen has been favored in light of 'recent concerns of increased cardiovascular risk associated with azithromycin

This article is written live from ID Week 2017 Annual Meeting in San Diego, CA. MPR will be reporting news on the latest findings from leading experts in infectious diseases. Check back for more news from IDWeek 2017.

SAN DIEGO—Findings from a retrospective cohort study found that compared to azithromycin, doxycycline was not associated with an increased risk in composite outcome among non-intensive care unit (ICU) veterans hospitalized with community-acquired pneumonia (CAP).

“There was no association between receipt of doxycycline and any of the individual components of the composite outcome,” the study authors reported.

The findings bolster the current Infectious Diseases Society of America (IDSA) CAP guideline recommendations that ceftriaxone + doxycycline be considered as an alternative to ceftriaxone + azithromycin for non-ICU patients hospitalized with CAP. This alternative is also favored in light of “recent concerns of increased cardiovascular risk associated with azithromycin,” noted lead study author Justin Spivey, PharmD, BCPS, from Mountain Home VA Healthcare System, Mountain Home, TN.

Dr. Spivey and colleagues conducted a retrospective study to compare clinical outcomes of doxycycline and azithromycin each in combination with ceftriaxone for this patient group. Included veterans had pneumonia in the VA MidSouth Healthcare Network (January 2007 to 2015) and were given either ceftriaxone + azithromycin or ceftriaxone + doxycycline within 48 hours of admission. The researchers also compiled patient demographics, Charleston Comorbidity Index (CCI), modified CURB-65, antimicrobials given, and microbiology data.

The composite outcome, used to determine clinical failure, included expanded antimicrobial coverage during the index hospitalization, mortality, readmission, or emergency department visit within 30 days.

Of 3,788 patients, 3,711 had received azithromycin and 77 received doxycycline. The cohorts were “well-matched according to CAP severity and comorbidities,” Dr. Spivey noted.

The coauthors found no statistical difference in the composite outcome between the 2 treatment arms (azithromycin: 44.3% vs. doxycycline 51.9%; P=0.18, n.s.). In multivariate analysis, several risk factors for composite outcome were identified: positive blood culture (odds ratio [OR] 5.81, 95% CI: 2.69–12.55), CURB-65 (2 vs. 0; OR 1.24, 95% CI: 1.05–1.47), CURB-65 (≥3 vs. 0; OR 2.4, 95% CI: 1.22–4.71) and CCI (OR 1.1, 95% CI: 1.06–1.14).

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Spivey, J. Retrospective Cohort Study of the Efficacy of Azithromycin Versus Doxycycline as Part of Combination Therapy in Non-Intensive Care Unit Veterans Hospitalized with Community-Acquired Pneumonia. Poster presented at IDWeek; October 4–8, 2017; San Diego, CA.