Tenofovir alafenamide

How it works

It is metabolised intracellularly to tenofovir diphosphate, which inhibits viral reverse transcriptase and causes chain termination of the growing viral DNA.

Prescribing in practice

• Hepatitis B status should be checked before treatment, as severe acute exacerbations of hepatitis B can occur if therapy is stopped in co-infected patients.
• It achieves lower plasma tenofovir concentrations than tenofovir disoproxil, with a generally more favourable renal and bone-density profile.
• Co-administration with strong inducers of P-glycoprotein can substantially reduce its concentrations and is not recommended.

Monitoring

Monitor renal function and, in hepatitis B, liver function, with continued follow-up after stopping in co-infected patients.

Counselling the patient

• Do not stop treatment without specialist advice, especially if you also have hepatitis B.
• Take it consistently as part of your full regimen to keep the virus suppressed.
• Report any new bone, kidney or liver symptoms.

Evidence & guidelines

Its efficacy and improved renal and bone safety relative to tenofovir disoproxil are established in randomised HIV and hepatitis B trials and supported by NICE-endorsed regimens.