entecavir monohydrate at a glance
Medicine class
Nucleoside analogue antiviral
Main licensed use
Chronic hepatitis B with specified evidence of active liver disease
Food
Usually with or without food; an empty stomach is required in some circumstances
What is entecavir monohydrate used for?
Licensed uses include:
Chronic hepatitis B in adults with compensated liver disease and evidence of active viral replication, persistent ALT elevation and active inflammation or fibrosis.
Chronic hepatitis B in adults with decompensated liver disease.
Chronic hepatitis B in nucleoside-naïve children and adolescents aged 2 to under 18 years with compensated liver disease and specified evidence of active disease.
Specialist services may also use it outside its licence to prevent hepatitis B reactivation during immunosuppressive treatment.
How does entecavir monohydrate work?
Inside cells, entecavir is converted to an active triphosphate form. This competes with a natural building block used by hepatitis B polymerase, interrupting viral DNA production and reducing the amount of virus present.
entecavir monohydrate preparations and strengths
Tablet
Route: Oral
Strengths: 0.5 mg, 1 mg
How to take entecavir monohydrate
Swallow the tablet exactly as prescribed. Do not stop without speaking to the specialist team because hepatitis can worsen afterwards.
It can usually be taken with or without food.
Follow the prescriber’s instructions if it must be taken on an empty stomach.
Tell the prescriber if tablets are difficult to swallow or kidney function changes, as another formulation or prescription adjustment may be needed.
entecavir monohydrate side effects
Common or expected effects
- Headache
- Tiredness
- Dizziness or sleepiness
- Difficulty sleeping
- Nausea, vomiting, diarrhoea or indigestion
- Increased liver enzymes
Get urgent medical advice
- Severe allergic reaction, including swelling or breathing difficulty
- Possible lactic acidosis, such as severe abdominal symptoms with nausea or vomiting
- Severe worsening of hepatitis, including after treatment stops
entecavir monohydrate in pregnancy
Human pregnancy information is limited and potential fetal risk is uncertain. It should be used only when clearly necessary following specialist review. It has not been shown to prevent transmission from mother to baby, so established neonatal preventive measures remain important.
entecavir monohydrate while breastfeeding
It is unknown whether entecavir enters human milk, and risk to the infant cannot be excluded. The selected product information advises stopping breastfeeding during treatment; discuss feeding and antiviral options with the specialist team.
entecavir monohydrate interactions
Important issues mainly concern kidney elimination and HIV treatment.
Medicines that reduce kidney function or compete for renal tubular secretion
They may increase exposure to entecavir or the other medicine, requiring closer monitoring of adverse effects and kidney function.
Ciclosporin or tacrolimus
Kidney function should be assessed carefully in liver-transplant recipients because impaired renal clearance can increase entecavir exposure.
Lamivudine, adefovir or tenofovir disoproxil
No pharmacokinetic interaction was observed, although antiviral history and resistance remain important when selecting therapy.
Common questions about entecavir monohydrate
Answers are fully visible for fast scanning and source review.
Does entecavir cure hepatitis B?
It suppresses viral replication and can improve liver disease, but is not described as a cure. Stopping it can allow hepatitis to worsen.
Can it be taken with food?
Usually yes, but some people must take it on an empty stomach. Follow the prescriber’s instructions.
Can hepatitis B still spread during treatment?
Yes. Treatment has not been proven to prevent transmission, so precautions against exposure to infected blood and body fluids remain necessary.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.