Oseltamivir and acute hepatitis, reality association or coincidence?

Oseltamivir is an orally administered antiviral medication that selectively inhibits the influenza neuraminidase enzymes that are essential for viral replication and it is active against both influenza A and B viruses. Oseltamivir is indicated for therapy or post-exposure prevention of influenza A and B. Side effects are uncommon and include mild nausea, gastrointestinal upset, dizziness, and headache. Despite widespread use, oseltamivir has not been associated with clinically apparent liver injury; however, there is growing evidence of possible toxic liver involvement during oseltamivir therapy. To the best of our knowledge, this is the first reported case in Italy linking the development of acute hepatitis and oseltamivir therapy, in a patient suffering from influenza H1N1 infection. We also present a review of the literature on cases of oseltamivir hepatotoxicity, through the consultation of PubMed database, the bibliographical references of various articles and an extensive search using Google. In view of the analyzed results, we suggest that experts should carefully consider the need for inclusion of potential serious liver reactions be added to the oseltamivir product label.