Enteclude - Precautions | Dosage instructions

Enteclude is a drug containing an active substance called entecavir. It belongs to the group of nucleoside reverse transcriptase inhibitors, and is used to treat chronic hepatitis B virus (HBV) infection.

Mechanism of action

After oral administration, this drug is subject to phosphorylation and is transferred into entecavir-triphosphate, which suppresses the deoxiguanosine - a physiological substrate for hepatitis B virus polymerase (HBVP). In this way, Enteclude inhibits all three steps in the replication process of hepatitis B virus:

  • Preparation of HBVP
  • Reverse transcription of the negative DNA strand from the pregenomic messenger RNA
  • Synthesis of the positive strand of hepatitis B virus DNA

This drug reduces the amount of hepatitis B virus by 50%.


Lange CM. et al, have reported cases of lactic acidosis in five patients (of 16 patients who participated in the study) of which one patient had a fatal outcome. Lactic acidosis is a condition characterized by an increase in lactic acid levels in the blood and symptoms of lactic acidosis include:

  • Muscle pain
  • Feeling hot or cold
  • Weakness
  • Drowsiness
  • Rapid breathing
  • Bradycardia
  • Arrhythmias
  • Vomiting
  • Abdominal pain

If you notice any of these symptoms, you should contact your doctor immediately.

FDA also warns of the possible occurrence of hepatomegaly with steatosis (so-called fatty liver), which may also have a fatal outcome. For this reason, the liver function should be monitored regularly while you are taking this medicine.

The acute exacerbation of hepatitis B virus infection, or worsening of the symptoms (even with fatal outcome), has also been reported, mainly in patients who have suddenly stopped using this drug.

Liver function must be monitored even after you discontinue therapy in order to detect eventual deterioration of the HBV infection.

This medication does not reduce the risk of HBV transmission, and patients are advised to avoid sexual contact while taking this medication.

Enteclude, Pregnancy and Breastfeeding

Studies that investigated the use of this medicine in rats at doses that are 3100 times higher than those used in humans have shown that this medicine reduces ossification and lowers birth weight, but there are no adequate studies in pregnant women. Therefore, the FDA classifies this drug in group C and advises its use only in cases where the doctor decides it is necessary.

Studies in rats have shown that this drug is excreted in milk of rats, but there is no data on whether it is excreted into breast milk. Breastfeeding should be discontinued while you are using this medicine.

Dosage instructions for patients above 16 years of age

In patients who are not previously treated with nucleoside analogues, the recommended dose is 0.5 mg once daily, two hours before or two hours after a meal, as food affects the absorption of the drug.

In patients refractory to lamivudine therapy, the recommended dose is 1 mg once daily.

Duration of treatment depends on the severity of the infection and the general health status of the patient. In patients with decompensated liver disease or cirrhosis, treatment discontinuation may cause acute exacerbation of the disease.

In patients with estimated creatinine clearance of 30-50 ml / min, the dose should be reduced by 50%, while in patients with estimated creatinine clearance of 10-30 ml / min the dose should be reduced by 70%.

In patients with severe renal impairment (creatinine clearance < 10 ml / min or hemodialysis patients), the recommended dose is 0.05 mg once daily for nucleoside-naive patients and 0.1 mg once daily for the treatment of lamivudine-refractory hepatitis B, respectively.


Major, clinically significant drug-drug interactions have not been reported, because the active ingredient - entecavir is neither inhibitor nor inducer of cytochrome P450 enzymes (more than one half of all known drugs are metabolized through these enzymes).

Moderate interactions are possible with the following drugs:

Side effects

The most commonly reported adverse reactions are:

  • Dizziness
  • Headache
  • Fatigue
  • Nausea

In addition, the following adverse effects have also been reported:

  • Alopecia (hair loss)
  • Insomnia
  • Diarrhea
  • Dyspepsia
  • Somnolence
  • Elevated levels of hepatic enzymes (AST and ALT)
  • Vomiting
  • Anaphylactic reactions


Information on this website are provided for educational purposes only and are not intended for medical advice, diagnosis or treatment.

If you have any concerns or questions about your health, you should always consult with a physician or other health-care professional.