Intravenous N-acetylcysteine and Oseltamivir Versus Oseltamivir in Adults Hospitalized With Influenza and Pneumonia

Inclusion Criteria: * influenza A and B virus infections confirmed by polymerase chain reaction (PCR) and/or immunofluorescence assays, * hospitalized for the management of severe manifestations of influenza, * initiation of oseltamivir, * clinical evidence of lower respiratory tract infection (e.g. shortness of breath, tachypnea, oxygen desaturation \<93% on room air, crepitations on auscultation, infiltrations or consolidations on chest radiograph) * written informed consent (by the subjects, or from their next of kin if the subjects are unable to provide written consent at the time of enrollment) Exclusion Criteria: * use of immunosuppressants (e.g. post-chemotherapy, post-transplant, autoimmune diseases) other than systemic corticosteroids * known immuno-compromised conditions (e.g. active haematological malignancies, HIV/AIDS patients who are on antiretroviral therapy and CD4 cell count \< 200), * pregnancy * lactation, * end-stage renal failure * hepatic failure * cardiac failure * patients on anticoagulation (except prophylactic dose of low molecular weight heparin), * patients with scheduled major surgery within 2 weeks (NAC may affect blood clotting), * patients who have received macrolide antibiotics and NSAID for 1 week prior to enrolment due to their immuno-modulating effects. * Use of investigational anti-influenza antivirals and blood products