entecavir: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
entecavir: clinical details
Prescribing considerations
- Initiation should be supervised by a clinician experienced in chronic hepatitis B management.
- Review renal function, liver disease severity, previous nucleoside analogue exposure, lamivudine resistance, HIV status and pregnancy considerations.
- Decompensated liver disease carries increased risks of serious hepatic events, renal complications and lactic acidosis.
- Entecavir does not remove the need for measures preventing hepatitis B transmission.
- Use for hepatitis B reactivation prevention during immunosuppression is a specialist, non-licensed context.
Contraindications and cautions
- Hypersensitivity to entecavir or any product excipient.
- The oral solution should not be used in hereditary fructose intolerance because it contains maltitol.
Monitoring
- HBV DNA and biochemical response, including liver enzymes.
- Renal function, particularly with impairment, transplantation, cyclosporine, tacrolimus or other renally active medicines.
- Clinical and laboratory evidence of hepatitis flare during treatment and after discontinuation.
- Virological response and resistance after previous lamivudine failure.
- Closer clinical and laboratory surveillance in decompensated liver disease.
Clinical pharmacology
A guanosine nucleoside analogue phosphorylated inside cells to entecavir triphosphate, which inhibits HBV polymerase. It has low protein binding, minimal CYP450 involvement and is eliminated predominantly unchanged through glomerular filtration and tubular secretion.
Formulation and product differences
- The oral solution is ready to use and supplied with a graduated measuring spoon.
- The solution must not be diluted or mixed with other liquids or medicines.
- The oral solution and tablets were bioequivalent in healthy volunteers.
- The oral solution contains maltitol and parahydroxybenzoate preservatives; tablets do not contain maltitol.
entecavir preparations and strengths
Oral solution
Route: Oral
Strengths: 0.05 mg/mL
entecavir interactions
Entecavir has relatively few established metabolic interactions, but kidney elimination and HIV treatment status are important.
Medicines that reduce kidney function or compete for renal tubular secretion
They may increase entecavir or co-administered medicine concentrations, requiring closer monitoring of adverse effects and kidney function.
Lamivudine, adefovir or tenofovir disoproxil
No pharmacokinetic interactions were observed, although previous lamivudine resistance remains clinically important.
Medicines metabolised through cytochrome P450 enzymes
Metabolic interactions are unlikely because entecavir does not inhibit, induce or act as a substrate for these enzymes.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.