Usual Adult Dose for Chronic Hepatitis B

10 mg orally once a day
Duration of therapy: Optimum duration not established

Comments:

• Indication based on histological, virological, biochemical, and serological responses in patients with hepatitis B e antigen (HBeAg)-positive and HBeAg-negative chronic hepatitis B with compensated liver function, and with clinical evidence of lamivudine-resistant HBV with compensated/decompensated liver function

Use: For the treatment of chronic HBV infection in patients with evidence of active viral replication and either evidence of persistent serum aminotransferase (ALT or AST) elevations or histologically active disease

Usual Pediatric Dose for Chronic Hepatitis B

12 years or older: 10 mg orally once a day
Duration of therapy: Optimum duration not established

Comments:

• Indication based on virological and biochemical responses in patients with HBeAg-positive chronic HBV infection with compensated liver function

Use: For the treatment of chronic HBV infection in patients with evidence of active viral replication and either evidence of persistent serum aminotransferase (ALT or AST) elevations or histologically active disease

Renal Dose Adjustments

Adults:

• CrCl at least 50 mL/min: No adjustment recommended.
• CrCl 30 to 49 mL/min: 10 mg orally every 48 hours
• CrCl 10 to 29 mL/min: 10 mg orally every 72 hours
• CrCl less than 10 mL/min (non-hemodialysis): Data not available

Adolescents: Data not available

Comments:

• Safety and efficacy of these dosing guidelines have not been clinically evaluated.
• These guidelines were derived from data in patients with preexisting renal dysfunction at baseline; may not be appropriate for patients whose renal dysfunction develops during therapy
• Clinical response to therapy and renal function should be closely monitored in these patients.

Liver Dose Adjustments

No adjustment recommended.

Precautions

US BOXED WARNINGS:

• POSTTREATMENT EXACERBATIONS OF HEPATITIS: Severe acute exacerbations of hepatitis reported in patients who discontinued antihepatitis B therapy (including this drug). Hepatic function should be monitored closely with both clinical and laboratory follow-up for at least several months in patients who discontinue antihepatitis B therapy. If appropriate, resumption of antihepatitis B therapy may be necessary.
• NEPHROTOXICITY: The chronic use of this drug in patients at risk of or having underlying renal dysfunction may result in nephrotoxicity. These patients should be monitored closely for renal function and may require dose adjustment.
• HIV RESISTANCE: HIV resistance may occur in chronic HBV-infected patients with unrecognized/untreated HIV infection treated with antihepatitis B therapies (including this drug) that may have activity against HIV.
• LACTIC ACIDOSIS/SEVERE HEPATOMEGALY WITH STEATOSIS: Lactic acidosis and severe hepatomegaly with steatosis (including fatalities) reported with use of nucleoside analogs alone or in combination with other antiretrovirals.

This drug is not recommended for use in children younger than 12 years.

Consult WARNINGS section for additional precautions.

Dialysis

Adults:

• Hemodialysis: 10 mg orally every 7 days after dialysis
• Peritoneal dialysis: Data not available

Adolescents: Data not available

Other Comments

Dose expressed as adefovir dipivoxil.

Administration advice:

• Before starting this drug, offer HIV antibody testing to all patients.
• Before starting this drug, calculate CrCl in all patients.
• May administer without regard to food

Storage requirements:

• Store in original container at 25C (77F); excursions permitted to 15C to 30C (59F to 86F).

General:

• To reduce risk of resistance in patients with lamivudine-resistant HBV, this drug should be used with lamivudine and not as monotherapy.
• To reduce risk of resistance in all patients using this drug as monotherapy, treatment modification should be considered if serum HBV DNA remains over 1000 copies/mL with continued therapy.
• The correlation between therapy response and long-term outcomes (e.g., hepatocellular carcinoma, decompensated cirrhosis) has not been established.

Monitoring:

• Hepatic: Hepatic function with clinical and laboratory follow-up (for at least several months after stopping therapy)
• Renal: Renal function in all patients (during therapy)

Patient advice:

• Read the US FDA-approved patient labeling (Patient Information).
• Avoid missing doses by following a regular dosing regimen.
• Report any severe abdominal pain, muscle pain, yellowing of eyes, dark urine, pale stools, and/or loss of appetite at once.