- Top of page
- Advantages of nucleos(t)ide analogues
- Limitations of nucleos(t)ide analogues
- Conflicts of interest
Current agents used in the treatment of chronic hepatitis B (CHB) can be classified into interferons-α (IFN-α: standard or pegylated) and nucleos(t)ide analogues (NUCs). NUCs are now used in most CHB patients for several reasons. They can be given to all CHB patients, even those with contraindications to IFN-α. NUCs are more convenient to use (one oral tablet daily) than IFN-α (subcutaneous injections) and are well tolerated with a good safety profile, while IFN-α has frequent and potentially severe side effects and worsens the patient's quality of life. All NUCs are potent anti-hepatitis B virus agents (all except adefovir are more potent than IFN-α) with entecavir and tenofovir being the most potent. Most importantly NUCs all have minimal risk of resistance during long-term monotherapy. Prolongation of entecavir or tenofovir monotherapy maintains and slightly increases the initially high virological remission rates (67–76% of HBeAg-positive and 90–93% of HBeAg-negative patients) and this is expected to result in improved long-term outcomes. The need for long-term, perhaps indefinite, treatment is the main limitation of NUCs and the finite duration (48 weeks) the main advantage of IFN-α. However, only a minority of IFN-α-treated patients achieve durable sustained off-treatment responses (HBeAg-positive: 30–35%, HBeAg-negative: 20–25%), while NUCs may be safely discontinued in HBeAg-positive patients with stable HBeAg seroconversion. Because there will always be concerns for safety and family planning issues with long-term therapy, NUCs should be used judiciously and should not be prescribed in young CHB patients with mild liver disease.