Nurses Compass
Drug Guide
Adefovir Dipivoxil
Classification
Therapeutic: Antiviral (Hepatitis B Virus infection)
Pharmacological: Reverse transcriptase inhibitor (nucleotide analog)
FDA Approved Indications
- Chronic hepatitis B in adults with active disease
Mechanism of Action
Adefovir inhibits hepatitis B virus DNA polymerase, leading to DNA chain termination and inhibition of viral replication.
Dosage and Administration
Adult: 10 mg once daily, with or without food.
Pediatric: Not approved for pediatric use.
Geriatric: Use with caution, considering renal function.
Renal Impairment: Reduce dosage based on renal function; monitor renal function closely.
Hepatic Impairment: No specific dose adjustment provided, but caution advised.
Pharmacokinetics
Absorption: Well absorbed orally.
Distribution: Widely distributed in body tissues.
Metabolism: Not extensively metabolized.
Excretion: Primarily excreted unchanged by the kidneys.
Half Life: Approximately 3 to 5 hours.
Contraindications
- Hypersensitivity to adefovir or any component of the formulation.
Precautions
- Renal impairment: use with caution, monitor renal function.
- Lactic acidosis and severe hepatomegaly have been reported with nucleoside analogues.
Adverse Reactions - Common
- Headache (Common)
- Nausea (Common)
- Elevated liver enzymes (Common)
Adverse Reactions - Serious
- Lactic acidosis (Rare)
- Severe hepatomegaly with steatosis (Rare)
- Renal dysfunction including Fanconi syndrome (Rare)
Drug-Drug Interactions
- Potential nephrotoxic drugs (e.g., aminoglycosides, contrast media)
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor renal function (serum creatinine, BUN), liver function tests, and viral load.
Diagnoses:
- Risk for renal impairment
- Knowledge deficit related to medication use
Implementation: Administer as prescribed; educate patient, ensure hydration, monitor renal function regularly.
Evaluation: Assess effectiveness by monitoring viral load decrease and liver function tests.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Report any signs of kidney problems (e.g., decreased urine output, swelling).
- Avoid nephrotoxic substances.
- Attend regular follow-up for blood tests.
Special Considerations
Black Box Warnings:
- Lactic acidosis and severe hepatomegaly with steatosis.
- Potential for renal toxicity.
Genetic Factors: None specific.
Lab Test Interference: Possible elevation of serum creatinine.
Overdose Management
Signs/Symptoms: Nausea, dizziness, potentially renal failure.
Treatment: Supportive care; hemodialysis may be considered in severe cases.
Storage and Handling
Storage: Store at room temperature away from moisture and heat.
Stability: Stable under recommended conditions.