Use of Favipiravir as a Broad-Spectrum Virostatic Drug in Lung Transplant Recipients

Introduction: Lung transplant recipients (LTRs) are at high risk for respiratory viral infections, which can lead to a range of complications including graft rejection. However, the limited number of antiviral drugs available makes treatment challenging. Favipiravir is a RNA dependent polymerase inhibitor approved as a virostatic drug against influenza virus, possessing the activity against a wide range of different RNA viruses. Objective: We aimed to assess the effectiveness of favipiravir in the treatment of non-influenza respiratory viral infections. Methods: We reviewed the LTRs tested positive for respiratory viruses by polymerase chain reaction in our cohort between January 2021 and January 2022. Based on the clinical condition, favipiravir was indicated for 10 days in 3 patients in standard dose of 1800 mg BID the first day, followed by 800 mg BID from the second day on. Results: 115 respiratory viral infections were diagnosed in 59 LTRs. Three female LTRs received favipiravir therapy: two for seasonal coronaviruses and one due to ribavirin side effects for respiratory syncytial virus. Two LTRs received the full length of treatment, the other one only 4 days due to nausea. The improvement of clinical condition was observed in all of them. No major complications of treatment were observed. No LTRs had acute rejection or onset of chronic lung allograft dysfunction during the following year. Conclusions: According to our limited experience, favipiravir may be used for treatment of the wider spectra of the respiratory viral infections with positive impact on the complications and survival of the patients. However, further studies on larger cohorts are needed.