Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Cancer: In animal studies, entecavir caused certain types of cancers. It is not known if these results will apply to human beings. Talk to your doctor if you have any concerns.
Hepatitis B transmission: Treatment with entecavir does not reduce the risk of passing on hepatitis B to other people through sexual contact and blood transfer. You should continue to take measures to prevent giving hepatitis B to other people (e.g., using condoms) while taking this medication.
Human immunodeficiency virus (HIV): People with HIV infection should discuss with their doctor how this medication may affect their medical condition. If you are taking entecavir for chronic hepatitis B and are not taking any medications for HIV at the same time, some HIV medications that you take in the future may not work as well to treat HIV. Entecavir has not been studied for the treatment of HIV. Your doctor may test you for HIV before beginning treatment with entecavir. If you think that you might have HIV contact your doctor immediately to get tested.
Kidney function: This medication is removed from the body by the kidneys. If the kidneys are not working properly, entecavir may build up in the body and cause side effects. People with reduced kidney function may need a different dose of the medication. Be sure to tell your doctor if you have a history of kidney disease.
Lactic acidosis and enlarged liver: Entecavir can cause a rare but serious condition called lactic acidosis (buildup of lactic acid in the blood) together with an enlarged liver and fat in the liver. If you experience any of the following symptoms, call your doctor immediately:
- abdominal pain, swelling, or bloating
- feeling unwell
- loss of appetite for several days
- shortness of breath
- skin or whites of eye turn yellow
- stools turn light in colour
- urine turns dark
- weight loss
Your doctor will periodically monitor you and perform laboratory tests to check your liver function.
Lactose intolerance: Entecavir tablets contain lactose. If you have been told that you are intolerant to lactose, contact your doctor before taking this medication.
Liver transplant: The safety and effectiveness of entecavir has not been tested in people who have had a liver transplant. It is not known if entecavir will interact with anti-rejection medications (i.e., cyclosporine, tacrolimus) commonly used after an organ transplant. If you have had a liver transplant, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Stopping the medication: If you stop taking entecavir, your hepatitis B infection could get worse. Take the medication exactly as prescribed by your doctor, and do not stop taking the medication without checking with your doctor first.
Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: It is not known if entecavir passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. 'Talk to your doctor about whether you should continue breast-feeding.
Children: The safety and effectiveness of using this medication have not been established for children under 16 years of age.