tenofovir alafenamide fumarate: clinical use

Prescribing considerations

• Initiation should be supervised by a clinician experienced in chronic hepatitis B management.
• Establish HIV status before treatment when unknown.
• Review renal function, liver disease severity, interacting medicines and other tenofovir-containing products.
• Data are limited in decompensated liver disease, where hepatic and renal monitoring should be closer.
• Paediatric bone mineral density reductions have been reported; determine monitoring according to clinical risk.

Contraindications and cautions

• Hypersensitivity to tenofovir alafenamide or any excipient.
• The tablet contains lactose and should not be used in specified rare hereditary disorders of galactose metabolism or absorption.

Monitoring

• Assess renal function before or when starting treatment and during therapy as clinically appropriate.
• Follow HBV DNA, liver biochemistry and clinical response.
• Monitor patients with cirrhosis or decompensated liver disease closely for hepatic flares or decompensation.
• Continue clinical and laboratory hepatic follow-up after planned discontinuation because severe flares can occur.
• Consider body weight, blood lipids and glucose, which may increase during therapy.

Clinical pharmacology

Tenofovir alafenamide is a P-glycoprotein and BCRP substrate and a hepatocyte-targeted prodrug. Intracellular conversion produces tenofovir diphosphate, which is incorporated by HBV reverse transcriptase into viral DNA and causes chain termination.

Formulation and product differences

• The selected product is an oral, yellow, round film-coated tablet that must be taken with food.
• It contains lactose and is essentially sodium-free.
• Tenofovir alafenamide fumarate is distinct from tenofovir disoproxil formulations and should not be duplicated with them.

Tablet

Route: Oral

Strengths: 25 mg