Generic
Entecavir
Pharmacology
By competing with the natural substrate deoxyguanosine triphosphate, entecavir functionally inhibits all three activities of the HBV polymerase (reverse transcriptase, rt): Base priming, Reverse transcription of the negative strand from the pregenomic messenger RNA, and Synthesis of the positive strand of HBV DNA. Upon activation by kinases, the drug can be incorporated into the DNA which has the ultimate effect of inhibiting the HBV polymerase activity.
Dosage Administration
The recommended dose of Entecavir for chronic hepatitis B virus infection in nucleoside-treatment-naive adults and adolescents 16 years of age is 0.5 mg once daily. For Lamivudine-refractory or known Lamivudine or Telbivudine resistance mutations, the recommended dose of Entecavir is 1 mg once daily. For patients with decompensated liver disease (adult) the recommended dose of Entecavir is 1 mg once daily. Entecavir should be administered on an empty stomach (at least 2 hours after a meal or 2 hours before the next meal). Missed Dose: If it is almost time for next dose, skip the missed dose and take the next dose at the proper time. Nobody should take a double dose to make up for the missed dose.
Contraindications
The most common adverse events are headache, fatigue, dizziness and nausea.
Side Effects
The most common adverse events are headache, fatigue, dizziness and nausea.
Pregnancy And Lactation
Lactic acidosis: Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases have been reported with the use of nucleoside analogues alone or in combination with antiretrovirals. Exacerbations of hepatitis after discontinuation of treatment: Severe acute exacerbations of hepatitis B have been reported in patients who have discontinued anti-hepatitis B therapy, including Entecavir.
Therapeutic
There is no experience of Entecavir overdosage reported in patients. Healthy subjects who received up to 20 mg daily for up to 14 days and single doses up to 40 mg had no unexpected adverse events. If overdosage occurs, the patient must be monitored for evidence of toxicity and standard supportive treatment as necessary.
Storage Conditions
Hepatic viral infections (Hepatitis B)