Entecavir

INTRODUCTION

Indications

Chronic hepatitis B infection with evidence of active disease.

Action

Phosphorylated intracellularly to active form which acts as an analogue of guanosine, interfering with viral DNA synthesis. Therapeutic Effects: Decreased hepatic damage due to chronic hepatitis B infection.

Adverse Reactions/Side Effects

CNS: dizziness, fatigue, headache. GI: HEPATOMEGALY (WITH STEATOSIS), dyspepsia, nausea. F and E: LACTIC ACIDOSIS. Derm: rash.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Be alert for signs of enlarged, fatty liver (hepatomegaly with steatosis) that can progress to liver dysfunction and liver failure. Signs of liver disease include anorexia, abdominal pain, abdominal swelling (ascites), severe nausea and vomiting, yellow skin or eyes, fever, sore throat, malaise, weakness, facial edema, lethargy, and unusual bleeding or bruising. Notify physician of these signs immediately.

• Monitor signs of lactic acidosis, including confusion, lethargy, stupor, shallow rapid breathing, tachycardia, hypotension, nausea, and vomiting. Notify physician immediately if these signs occur.

• Assess dizziness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician, and caution the patient and family/caregivers to guard against falls and trauma.

Interventions

• Because of the risk of lactic acidosis, use caution during aerobic exercise and other forms of therapeutic exercise. Assess exercise tolerance frequently (blood pressure, heart rate, fatigue levels), and terminate exercise immediately if any untoward responses occur (See Appendix L).

Patient/Client-Related Instruction

• Inform patient that entecavir does not cure hepatitis B virus (HBV), but may lower the amount of HBV in the body, may lower the ability of HBV to multiply and infect new liver cells, and may improve the condition of the liver. Entecavir does not reduce the risk of transmission of HBV to others through sexual contact or blood contamination. Caution patient to use a condom during sexual contact and to avoid sharing needles or donating blood to prevent spreading HBV to others.

• Instruct patient to report other troublesome side effects such as prolonged or severe headache, fatigue, skin rash, or GI problems (nausea, indigestion).

Pharmacokinetics

Absorption: Well absorbed following oral administration.

Distribution: Extensive tissue distribution.

Metabolism and Excretion: 62–73% excreted unchanged by kidneys.

Half-life: Plasma—128–149 hr; intracellular—15 hr.

Contraindications/Precautions

Contraindicated in: Hypersensitivity; Lactation: Lactation.

Use Cautiously in: Renal impairment (dose ...