Confirmation of the Antiviral Effects of Midodrine Identified With a Gene Expression Signature-based Screening of Inluenza A Virus Infected Cells

Rationale: Classical antiviral therapies target viral proteins and are consequently subject to resistance. To counteract this limitation, alternative strategies have been developed that target cellular factors. We hypothesized that such an approach could also be useful to identify broad-spectrum antivirals. The influenza A virus was used as a model for its viral diversity and because of the need to develop therapies against unpredictable viruses as recently underlined by the H1N1 pandemic. Gene-expression signature-based screening identified broadly effective influenza A antivirals. Midodrine showed great results in inhibiting viral growth and was the most suited to confirm its efficacy in vivo. The main objective of the study is to assess the efficacy of midodrine taken at usual recommended dose (7.5mg/day) versus no treatment on viral replication kinetics of virus Influenza A. Secondary objectives: evaluation of the number of patients with a normalized viral load 2, 3 5 and 7 days post-treatment; description of the anti-viral efficacy of midodrine defined as the delay to obtain a prolonged negativity of viral RNA; description of the tolerance of midodrine, evaluation of the clinical response to study treatment; evaluation of the dynamic of viral replication; analysis of the frequency of emergence of mutants and associated resistance. Methods: This is a multicenter, randomized, open-label study comparing patients aged 18 to 65 years infected by influenza A virus. Nasopharyngeal washing will be performed at day 0 (randomization), 2, 3, 5 to show the viral replication evolution. 161 patients will be randomized as follows : * Arm 1 : Midodrine, 2.5 mg, 3 times a day * Arm 2 : No treatment The recruitment is performed by general practitioners in the Lyon area.