Amiodarone is a class III antiarrhythmic medication used to treat atrial and
ventricular tachyarrhythmias.
Pulmonary fibrosis from
amiodarone use is a well-documented side effect. Pre-COVID-19 pandemic studies have shown that
amiodarone-induced
pulmonary fibrosis occurs in 1%-5% of patients and usually occurs between 12 to 60 months after initiation. The risk factors associated with
amiodarone-induced
pulmonary fibrosis include a high total cumulative dose (treatment longer than two months) and high maintenance dose (>400 mg/day).
COVID-19 infection is also a known risk factor for developing
pulmonary fibrosis and occurs in approximately 2%-6% of patients after a moderate illness. This study aims to assess the incidence of
amiodarone in
COVID-19 pulmonary fibrosis (ACPF). This is a retrospective cohort study with 420 patients with
COVID-19 diagnoses between March 2020 and March 2022, comparing two populations,
COVID-19 patients with exposure to
amiodarone (N=210) and
COVID-19 patients without
amiodarone exposure (N=210). In our study,
pulmonary fibrosis occurred in 12.9% of patients in the
amiodarone exposure group compared to 10.5% of patients in the
COVID-19 control group (p=0.543). In multivariate logistic analysis, which controlled for clinical covariates,
amiodarone use in
COVID-19 patients did not increase the odds of developing
pulmonary fibrosis (odds ratio (OR): 1.02, 95% confidence interval (CI): 0.52-2.00). The clinical factors associated with the development of
pulmonary fibrosis in both groups included a history of preexisting
interstitial lung disease (ILD) (p=0.001), exposure to prior
radiation therapy (p=0.021), and higher severity of
COVID-19 illness (p<0.001). In conclusion, our study found no evidence that
amiodarone use in
COVID-19 patients increased the odds of developing
pulmonary fibrosis at six-month follow-up. However, long-term
amiodarone usage in the
COVID-19 population should be based on the physician's discretion.