Taking entecavir for back pain is generally considered to be unrelated to the drug, and may be induced by trauma, degeneration, deformity, inflammation, tumor, and other causes. 1. trauma: whether it is acute lumbar sprain or chronic lumbar muscle strain, it will cause low back pain. 2. Degeneration: with age, the body’s tissue structure and lumbar discs will degenerate to induce low back pain. 3. Deformity: For example, the structure or shape of the lumbar spine is deformed, and once abnormal force is exerted, it will induce low back pain. 4. Inflammation: Generally, it is related to cold or strain, which will cause local myofascial inflammation and induce low back pain. 5. Tumor: For example, the tumor of lumbar spine may also induce low back pain. 6. Other causes: for example, visceral lesions, including urinary stones, endocrine diseases and rheumatism, etc., also have caused low back pain. Common adverse effects of entecavir include nausea, vomiting, headache, fatigue and dizziness, etc. It is contraindicated for those who are allergic to entecavir. In addition, patients need to take entecavir under the guidance of a doctor, do not take the drug blindly.