Entecavir belongs to guanine nucleoside analogs and can be divided into tablets and capsules. Some patients taking entecavir may experience side effects such as body weakness, hair loss, rash, headache, nausea, dizziness, and elevated aminotransferase. Entecavir is indicated for patients with chronic hepatitis B with active viral replication and persistent elevation of serum alanine aminotransferase. Entecavir should be contraindicated if the patient is hypersensitive to any of the components in entecavir. If the patient has renal insufficiency, entecavir also needs to be taken with caution under the guidance of a doctor. If you suffer from hepatitis B and other diseases, patients need to strictly follow the doctor’s instructions to take entecavir according to the course of treatment, to prevent unauthorized use of drugs on the body to cause negative effects.