Antiviral drug, guanosine nucleoside analogue with potent and selective activity against hepatitis B virus (HBV) polymerase.
Entecavir is phosphorylated to form active triphosphate, which has an intracellular half-life of 15 h. The intracellular concentration of entecavir triphosphate is directly related to the extracellular level of entecavir, with no significant accumulation of the drug after the initial “plateau” level.
Chronic hepatitis B in adults with compensated liver damage and the presence of viral replication, elevated serum transaminase activity (ALT or ACT) and histological signs of liver inflammation and/or fibrosis; with decompensated liver damage.
How to take, the dosage
It is taken orally. The dose is 500-1000 mcg once daily.
Since entecavir is mainly excreted by the kidneys, concomitant administration of entecavir and drugs that cause renal dysfunction or compete at the level of tubular secretion may increase the serum concentration of entecavir or these drugs.
The interaction of entecavir with other drugs that are excreted by the kidneys or that affect renal function has not been studied. When concomitant use of entecavir with such drugs, the patient’s condition should be closely monitored.
During treatment with nucleoside analogues, including entecavir, as monotherapy and in combination with antiretroviral drugs there have been described cases of lactacidosis and marked hepatomegaly with steatosis, sometimes leading to the death of the patient.
Symptoms that may indicate the development of lactacidosis: general fatigue, nausea, vomiting, abdominal pain, sudden weight loss, shortness of breath, rapid breathing, muscle weakness.
Risk factors are female sex, obesity, long-term use of nucleoside analogues, hepatomegaly. If the above mentioned symptoms appear or if laboratory confirmation of lactacidosis is obtained, treatment with the drug should be stopped.
Cases of exacerbation of hepatitis after cancellation of antiviral therapy, including entecavir, have been described. Most of these cases passed without treatment. However severe exacerbations may develop, including fatal ones. The causal relationship of these exacerbations to discontinuation of therapy is unknown. Periodic monitoring of liver function is necessary after discontinuation of therapy. If necessary, antiviral therapy may be resumed.
It should be considered that when entecavir is used in patients with HIV co-infection who are not receiving antiretroviral therapy, there may be a risk of developing resistant strains of HIV. Entecavir has not been studied for the treatment of HIV infection and is not recommended for this use.
A high risk of serious hepatic side effects has been noted, particularly in patients with decompensated Child-Pugh class C liver damage. These patients are also at higher risk of lactacidosis and specific renal side effects such as hepatorenal syndrome. In this regard, patients should be closely monitored for clinical signs of lactacidosis and impaired renal function, as well as appropriate laboratory tests in this group of patients (activity of liver enzymes, lactic acid concentration in blood, serum creatinine concentration).
Presence of resistance mutations in hepatitis B virus to lamivudine increases risk of entecavir resistance development. In this regard, in lamivudine-resistant patients frequent monitoring of viral load and, if necessary, appropriate examination to detect resistance mutations is required.
For patients with impaired renal function, correction of the dosing regimen is recommended.
Safety and effectiveness of entecavir in patients who have undergone liver transplantation is unknown. Renal function should be carefully monitored before and during treatment with entecavir in patients who have undergone liver transplantation and are receiving immunosuppressants that may affect renal function, such as cyclosporine and tacrolimus.
Children and adolescents under 18 years of age; hypersensitivity to entecavir.
The digestive system: rarely – diarrhea, dyspepsia, nausea, vomiting; possibly – increased activity of transaminases.
Lek d.d., Slovenia
Buy Entecavir Sandoz, 0.5 mg 30 pcs with delivery to USA, UK, Europe and over 120 other countries.