Pyroxin can be discontinued for 1 year of treatment, but has many adverse effects; first-line nucleoside analogs are effective, but long-term treatment is required. Tenofovir is not resistant and very potent, but not without concerns for patients with underlying renal dysfunction. Many people are not yet satisfied with the current drugs for chronic hepatitis B. Recently, there have been constant questions: Is there a new drug from abroad? Tenofovir without kidney damage: Tenofovir is currently the most potent anti-hepatitis B virus drugs, just a few months to reduce inflammation and enzymes, within 1 year of the virus to negative (accurate quantification must be 2 years), clinical impression of some patients with E antigen to negative time is shorter, surface antigen titer reduction may be faster. It has a high rate of reversal of liver fibrosis and mild cirrhosis, and may also substantially reduce the incidence of hepatocellular carcinoma. In addition, this drug does not affect fertility or breastfeeding. It has been used for 9 years for the treatment of hepatitis B. To date, there are no confirmed reports of drug resistance in China or abroad. Alcohol abuse, chemotherapy or adrenocorticosteroids significantly affect its efficacy, but resistance has not been observed. However, tenofovir has slightly more adverse effects than entecavir, such as rising creatine kinase, chronically high transaminases, rash, frequent stools and certain other discomforts in a small number of patients, who have discontinued the drug because they could not tolerate it. The problem is that some patients with hepatitis B who may have potentially poor renal function, such as those over 50 years old mostly have some renal arteriosclerosis, hypertension, high blood creatinine or a small amount of protein in the urine routine. Patients with compensated cirrhosis are best treated with tenofovir for a long time; patients with past lamivudine resistance are also best treated with tenofovir for a long time; patients with hepatitis B who must take corticosteroids for various diseases, or patients with hepatitis B who must undergo long-term anti-rejection therapy after transplantation, as well as chemotherapy for tumors, only tenofovir can control the virus without drug resistance. Chronic hepatitis B is a common disease, and patients with both of these conditions would not be a minority, and they need tenofovir without renal damage. New version of tenofovir: 1/10 of the dose but has the same efficacy: a new synthetic tenofovir (TDF) new version of Tenofoviral afenamide, not yet translated, referred to as TAF, has completed phase III clinical trials: the best dose of 25mg / 1 tablet / 1 day, less than 1/10 of tenofovir 300mg, the same efficacy, the dose is small, of course, adverse reactions The main reason is that there is absolutely no kidney damage. How can such a small dose of TAF have the same efficacy? Lamivudine, telbivudine and entecavir are monophosphate nucleosides, while adefovir and tenofovir are diphosphate nucleotides, all of which have no direct anti-hepatitis B virus activity, and are all precursors that have no effect. They are absorbed from the intestinal canal into the liver and become nucleotide triphosphates through the action of cellular phosphatases before they have antiviral activity. TDF and TAF are also precursors of diphosphate nucleotides, which are absorbed from the intestinal tract into the blood, but a large proportion of TDF precursors cannot enter, while TAF precursors can almost all enter the liver, and after the action of cellular phosphatase, the amount of nucleotide triphosphate salt is similar, so the effect of removing hepatitis B virus is the same. The TDF precursors that remain in the blood are many, but the TAF is few, and the precursors are not antiviral but have adverse effects, so the TAF with few blood precursors is safer than the TDF with many blood precursors.