Entecavir
Indications
Entecavir is used for:
Chronic hepatitis B
Adult Dose
Chronic Hepatitis B
Indicated for treatment of CHB with evidence of active viral replication and either evidence of persistent elevations in serum aminotransferases (ALT or AST) or histologically active disease
Nucleoside inhibitor treatment-naïve with compensated liver disease (adults and adolescents ?16 yr): 0.5 mg PO qDay
Lamivudine-refractory or known lamivudine or telbivudine resistance substitutions (adults and adolescents ?16 yr): 1 mg PO qDay
Decompensated liver disease (adults): 1 mg PO qDay
Child Dose
Chronic Hepatitis B
Indicated for treatment of CHB with evidence of active viral replication and either evidence of persistent elevations in serum aminotransferases (ALT or AST) or histologically active disease in children ?2 years and weigh at least 10 kg
<2 years: Safety and efficacy not established
>16 years: As adult
Renal Dose
Renal Impairment
Usual daily dose (0.5 mg)
CrCl ?50 mL/min: No dosage adjustment required
CrCl 30-49 mL/min: Reduce to 0.25 mg/day or 0.5 mg q48hr
CrCl 10-29 mL/min: Reduce to 0.15 mg/day or 0.5 mg q72hr
CrCl <10 mL/min, hemodialysis, or CAPD: 0.05 mg/day or 0.5 mg q7days
Lamivudine-refractory/decompensated liver disease daily dose (1 mg)
CrCl ?50 mL/min: No dosage adjustment required
CrCl 30-49 mL/min: Reduce to 0.5 mg/day or 1 mg q48hr
CrCl 10-29 mL/min: Reduce to 0.3 mg/day or 1 mg q72hr
CrCl <10 mL/min, hemodialysis, or CAPD: 0.1 mg/day or 1 mg q7days
Administration
Should be taken on an empty stomach. Take at least 2 hr after a meal & 2 hr before the next meal. Use oral solution when needed for renal impairment dosage adjustments.
Contra Indications
Entecavir is contraindicated in patients with previously demonstrated hypersensitivity to Entecavir or any component of the product.
Precautions
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.
Lactation: excretion in milk unknown/not recommended
Pregnancy-Lactation
Pregnancy
Prospective pregnancy data from the APR are not sufficient to adequately assess the risk of birth defects, miscarriage or adverse maternal or fetal outcomes; use during pregnancy has been evaluated in a limited number of individuals reported to APR and number of exposures to entecavir is insufficient to make a risk assessment compared to a reference population; rate of miscarriage is not reported in APR; all pregnancies have a background risk of birth defect, loss, or other adverse outcomes
Lactation
Not known whether drug is present in human breast milk, affects human milk production, or has effects on the breastfed infant; when administered to lactating rats, entecavir was present in milk; developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for therapy and any potential adverse effects on breastfed infant from drug or from underlying maternal condition
Interactions
Drugs that reduce renal function or compete for active tubular secretion may increase serum conc of either entecavir or co-administered drug.
Side Effects
Side effects of Entecavir :
1-10%
Fatigue (1-3%), Headache (2-4%), Dizziness, Nausea
<1%
Diarrhea, Dyspepsia, Vomiting, Somnolence, Insomnia
Mode of Action
Selective HBV DNA polymerase inhibitor; inhibition blocks reverse transcriptase activity, which in turn reduces viral DNA synthesis