Impact of Administering Intravenous Azithromycin within 7 Days of Hospitalization for Influenza Virus Pneumonia: A Propensity Score Analysis Using a Nationwide Administrative Database

• Published in: Viruses
• Main Authors: Takatomo Tokito, Takashi Kido, Keiji Muramatsu, Kei Tokutsu, Daisuke Okuno, Hirokazu Yura, Shinnosuke Takemoto, Hiroshi Ishimoto, Takahiro Takazono, Noriho Sakamoto, Yasushi Obase, Yuji Ishimatsu, Yoshihisa Fujino, Kazuhiro Yatera, Kiyohide Fushimi, Shinya Matsuda, Hiroshi Mukae
• Format: Article
• Language: English
• Published: MDPI AG 2023-05-01
• Subjects: azithromycin; seasonal influenza virus; COVID-19; coronavirus disease; acute respiratory distress syndrome; infection
• Online Access: https://www.mdpi.com/1999-4915/15/5/1142

The potential antimicrobial and anti-inflammatory effectiveness of azithromycin against severe influenza is yet unclear. We retrospectively investigated the effect of intravenous azithromycin administration within 7 days of hospitalization in patients with influenza virus pneumonia and respiratory failure. Using Japan’s national administrative database, we enrolled and classified 5066 patients with influenza virus pneumonia into severe, moderate, and mild groups based on their respiratory status within 7 days of hospitalization. The primary endpoints were total, 30-day, and 90-day mortality rates. The secondary endpoints were the duration of intensive-care unit management, invasive mechanical ventilation, and hospital stay. The inverse probability of the treatment weighting method with estimated propensity scores was used to minimize data collection bias. Use of intravenous azithromycin was proportional to the severity of respiratory failure (mild: 1.0%, moderate: 3.1%, severe: 14.8%). In the severe group, the 30-day mortality rate was significantly lower with azithromycin (26.49% vs. 36.65%, <i>p</i> = 0.038). In the moderate group, the mean duration of invasive mechanical ventilation after day 8 was shorter with azithromycin; there were no significant differences in other endpoints between the severe and moderate groups. These results suggest that intravenous azithromycin has favorable effects in patients with influenza virus pneumonia using mechanical ventilation or oxygen.