Severe acute exacerbations of hepatitis have been reported in patients who have discontinued anti-Hepatitis B therapy including HEPSERA. Hepatic function should be monitored closely with both clinical and laboratory follow-up for at least several months in patients who discontinue anti-Hepatitis B therapy. If appropriate, resumption of anti-Hepatitis B therapy may be warranted [see WARNINGS AND PRECAUTIONS].

In patients at risk of or having underlying renal dysfunction, chronic administration of HEPSERA may result in nephrotoxicity. These patients should be monitored closely for renal function and may require dose adjustment [see WARNINGS AND PRECAUTIONS and DOSAGE AND ADMINISTRATION].

HIV resistance may emerge in chronic hepatitis B patients with unrecognized or untreated Human Immunodeficiency Virus (HIV) infection treated with anti-hepatitis B therapies, such as therapy with HEPSERA, that may have activity against HIV [see WARNINGS AND PRECAUTIONS].

Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs alone or in combination with other antiretrovirals [see WARNINGS and PRECAUTIONS].