Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible fibrotic lung disease with a variable disease course. Most patients with IPF have a relatively slow clinical course, but up to 15% of patients experience an acute exacerbation of IPF (AE-IPF) each year, defined as an acute worsening or development of dyspnea and new bilateral ground-glass abnormality and/or consolidation on high-resolution computed tomography (HRCT). A recent epidemiologic survey of Japanese patients with IPF showed that the most common cause of death was AE-IPF.~The outcome of AE-IPF is very poor. The reported 1-month mortality rate is approximately 60%, and the reported in-hospital mortality rate ranges from 50 to 60%.~AE-IPF lacks an effective pharmaceutical treatment. Current guidelines recommend that most patients with AE-IPF should be treated with corticosteroids, but no controlled trials support this recommendation. The International Working Group recently proposed a revised definition and diagnostic criteria for AE-IPF. Previous diagnostic criteria. recommended the strict exclusion of other causes of acute worsening of respiratory disease, but new criteria have permitted physicians to include patients with triggered AE in addition to idiopathic AE-IPF.~In studies of the treatment and outcomes of AE-IPF, almost all patients received empirical antibiotics in addition to corticosteroids despite the lack of controlled trials showing the benefit of empirical treatment.~Azithromycin is a macrolide with immunomodulatory properties and anti-inflammatory effects. Previous reports have described the effectiveness of macrolides in patients with serious conditions, such as severe pneumonia and acute lung injury. Until 2011, erythromycin was the only macrolide that could be used by intravenous injection in Japan. Still, erythromycin has many side effects and drug interactions, so we did not routinely use intravenous erythromycin in daily clinical practice. In cases of suspected AE-IPF, we used quinolone-based antibiotics. Intravenous azithromycin has been approved for clinical use since September 2011 in Japan. Azithromycin is safer and easier to use than erythromycin, and since the publication of Walkey's report, we routinely use azithromycin for patients with acute respiratory failure since July 2012. We previously reported that intravenous azithromycin was associated with improved outcomes in patients with AE of chronic fibrosing interstitial pneumonia. However, that report had two major limitations: the very small number of patients treated with azithromycin and the inclusion of patients with nonspecific interstitial pneumonia and chronic hypersensitivity pneumonia.
The study will assess the role of using azithromycin in managing acute exacerbation of Idiopathic pulmonary fibrosis