Tenofovir and Adefovir are both nucleoside analogs, Tenofovir has stronger antiviral activity and higher safety, while Adefovir has greater nephrotoxicity and side effects, and Tenofovir is generally considered to be better. 1. Tenofovir: Tenofovir is the first-line anti-hepatitis B virus drug, with stronger antiviral activity, better safety and lower drug resistance. Common adverse reactions include headache, dizziness, dyspnea, nausea, vomiting and loss of appetite, etc. Tenofovir is contraindicated for those who are allergic to Tenofovir. 2. Adefovir: Adefovir is the second-line anti-hepatitis B virus drug, with strong nephrotoxicity, taking this drug needs to receive regular kidney function tests. Its common adverse reactions, including nephrotoxicity, lactic acidosis, hepatomegaly, and human immunodeficiency virus resistance, etc. Adefovir is contraindicated for those who are allergic to adefovir. All of the above drugs have certain risks, if you need to use the drug, you need to regulate the use of under the guidance of a specialist.