Adult: PO: (age > 12 year) 10 mg, once daily.

Hepatic viral infections (Hepatitis B)

Adefovir dipivoxil is a diester prodrug of adefovir. Adefovir is an acyclic nucleotide analog with activity against human hepatitis B virus (HBV). Adefovir is phosphorylated to the active metabolite, adefovir diphosphate, by cellular kinases. Adefovir diphosphate inhibits HBV DNA polymerase (reverse transcriptase) by competing with the natural substrate deoxyadenosine triphosphate and by causing DNA chain termination after its incorporation into viral DNA. The approximate oral bioavailability of adefovir from a 10 mg single dose is 59%. In vitro binding of adefovir to human plasma or human serum proteins is 4%. Adefovir is excreted through renal route by a combination of glomerular filtration and active tubular secretion.

Administration: Increased risk of nephrotoxicity with nephrotoxic drugs e.g. aminoglycosides, ciclosporin, NSAIDs, vancomycin, tacrolimus. Ibuprofen increases bioavailability of adefovir. Adult Dose: Pregnancy; elderly; child; renal or hepatic impairment. HIV antibody testing to be performed before initiation due to possible resistance development in untreated HIV infection. Increased risk of hepatotoxicity in females, obese patients and with prolonged treatment. Monitor renal function every 3 mth; hepatitis B biochemical, viral and serological markers every 6 mth and LFTs. Discontinue therapy if liver function worsens, severe hepatomegaly, steatosis or unexplained metabolic or lactic acidosis. Monitor hepatic function for several mth in patients whose antihepatitis therapy is discontinued as acute exacerbations of hepatitis may occur. Lactation: Unknown if excreted in breast milk. Renal Dose: Adefovir dipivoxil is an acyclic nucleoside reverse transciptase inhibitor. The diester function is hydrolyzed and subsequently phosphorylated to the active adefovir diphosphate. The active metabolite inhibits HBV DNA polymerase (reverse transcriptase) and hence inhibits viral replication. It can be used in patients with lamivudine-resistant hepatitis B.

Adefovir Dipivoxil is contraindicated in patients with previously demonstrated hypersensitivity to any of the components of the product.

Adefovir dipivoxil is contraindicated in patients with previously demonstrated hypersensitivity to any of the components of the product.

Renal impairment: Haemodialysis patients: 10 mg every 7 days after dialysis. CrCl (ml/min) 30-49 10 mg every 48 hr. 10-29 10 mg every 72 hr.

Pregnancy Category C. There are no adequate and well-controlled studies in pregnant women. Adefovir dipivoxil should be used during pregnancy only if clearly needed and after careful consideration of the risks and benefits. It is not known whether adefovir is excreted in human milk. Mothers should be instructed not to breast-feed if they are taking adefovir dipivoxil.

Precaution: Chronic hepatitis B

Doses of adefovir dipivoxil 500 mg daily for 2 weeks and 250 mg daily for 12 weeks have been associated with gastrointestinal side effects. If overdose occurs the patient must be monitored for evidence of toxicity and standard supportive treatment applied as necessary.

Store at cool and dry place. Protect from light and moisture. Keep all the medicines out of the reach of children.

Hepatic viral infections (Hepatitis B)

Taken orally, without regard to food.

>10% Hematuria (11% vs 10% in placebo-treated),Asthenia (13% vs. 14% placebo),Hepatitis exacerbation (25%) 1-10% Nausea (5%),Flatulence (4%),Diarrhea (3%)Dyspepsia (3%),Headache (9%),Rash (1-10%),Pruritus (1-10%),Dyspepsia (5-9%),Cough (6-8%),Rhinitis (5%) Increased AST/ALT,Abnormal liver function,Renal failure,Renal insufficiency,Increased serum Cr (2-3%),Hypophosphatemia Potentially Fatal: Lactic acidosis, severe hepatomegaly with steatosis, hepatotoxicity, nephrotoxicity.