Entecavir

Entecavir is used in the treatment of HIV infection and chronic hepatitis B virus (HBV) infection. It prevents the multiplication of virus in human cells. This stops the virus from producing new viruses and clears up your infection.

Entecavir is not a cure for HIV or AIDS and only helps to decrease the amount of HIV in your body. This helps to lower your risk of getting HIV-related complications and improves your lifespan. It is prescribed in combination with other HIV medicines.

It can be taken with or without food but is best taken on an empty stomach. Taking all these medicines regularly at the right times greatly increases their effectiveness and reduces the chances of HIV becoming resistant to them. It is important not to miss doses and to keep taking them until your doctor tells you it is safe to stop.

• Chronic Hepatitis B Virus (HBV) Infection: Used for the 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 patients 2 years and older.

Hepatic viral infections (Hepatitis B)

Nucleoside Analog (HBV Polymerase Inhibitor)

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.

Selective HBV DNA polymerase inhibitor; inhibition blocks reverse transcriptase activity, which in turn reduces viral DNA synthesis.

Adult Dose:

• Nucleoside inhibitor-naïve (compensated liver disease): 0.5 mg PO qDay.
• Lamivudine-refractory (or telbivudine resistance): 1 mg PO qDay.
• Decompensated liver disease: 1 mg PO qDay.

Child Dose (≥2 years, ≥10 kg): Under 16 years: 0.015-0.03 mg/kg; 16 years: as adult.

Renal Dose:

• CrCl ≥50 mL/min: No dosage adjustment required
• CrCl 30-49 mL/min: 0.25 mg/day or 0.5 mg q48hr
• CrCl 10-29 mL/min: 0.15 mg/day or 0.5 mg q72hr
• CrCl <10 mL/min (dialysis/CAPD): 0.05 mg/day or 0.5 mg q7days

Take this medicine in the dose and duration as advised by your doctor. Swallow it as a whole. Do not chew, crush or break it. Entecavir is to be taken on an empty stomach (at least 2 hours after a meal or 2 hours before the next meal).

If you miss a dose of Entecavir, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular schedule. Do not double the dose.

Common Side Effects:

• Headache
• Dizziness
• Tiredness
• Nausea

Precautions:

• Entecavir may decrease alertness, affect your vision or make you feel sleepy and dizzy. Do not drive if these symptoms occur.
• Take it on an empty stomach (at least 2 hours after or before a meal).
• Entecavir may cause dizziness or sleepiness. Do not drive or do anything requiring concentration until you know how it affects you.
• You may still develop infections or other illnesses associated with viral infection while taking this medication.
• During treatment and for at least six months after stopping this medicine, regular blood tests are needed to monitor your liver function, level of hepatitis B virus and blood cells in your blood.

Contraindications: Previously demonstrated hypersensitivity to Entecavir or any component of the product.

Drug Interactions: Drugs that reduce renal function or compete for active tubular secretion may increase serum concentrations of either entecavir or co-administered drug.

Food Interactions: It is not known whether it is safe to consume alcohol with Entecavir. Consult your doctor. Alcohol may increase your risk of liver damage.

Use in Pregnancy: Entecavir may be unsafe to use during pregnancy. Although there are limited studies in humans, animal studies have shown harmful effects on the developing baby. Your doctor will weigh the benefits and any potential risks before prescribing it to you. Consult your doctor.

Use in Lactation: Entecavir is probably unsafe to use during breastfeeding. Limited human data suggests that the drug may pass into the breastmilk and harm the baby. Mothers should be instructed not to breastfeed if they are taking Entecavir.

Pediatric Use: Safety and effectiveness of Entecavir in pediatric patients below the age of 2 years have not been established.

Geriatric Use: Clinical studies did not include sufficient numbers of subjects aged 65 years and over. Care should be taken in dose selection, and it may be useful to monitor renal function.

Renal Impairment: Use with caution in patients with kidney disease. Dose adjustment may be needed. Consult your doctor.

Hepatic Impairment: Entecavir is safe to use in patients with liver disease. No dose adjustment is recommended.

Overdose: 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: Keep in a dry place and store below 30°C. Protect from light and keep out of the reach of children.

Entecavir