Tenofovir alafenamide

Deterministic view of the source YAML entity. Clinical authority remains with the cited source IDs and reviewer sign-off state.

ID	`DRUG-TENOFOVIR-AF`
Type	Drug
Aliases	TAFTenofovir AFVemlidyТенофовіру алафенамід
Status	reviewed 2026-05-18
Diseases	None declared
Sources	`SRC-AASLD-HBV-2024` `SRC-NIH-AIDS-2024`

Drug Facts

Class	Nucleotide analog reverse transcriptase inhibitor (NRTI / NtRTI) — second-generation tenofovir prodrug
Mechanism	Second-generation phosphonamidate prodrug of tenofovir; stabilized to resist plasma hydrolysis (versus TDF) so it preferentially delivers tenofovir intracellularly to hepatocytes (HBV) and lymphocytes (HIV). Once in target cell, intracellular cathepsin A cleaves TAF to tenofovir, which is then phosphorylated to tenofovir-DP and competitively inhibits HBV polymerase / HIV-1 reverse transcriptase with chain termination. Yields ~90% lower systemic tenofovir exposure than TDF at equivalent intracellular concentrations — reduced renal and bone toxicity.
Typical dosing	Chronic HBV (adult, compensated liver disease): 25 mg PO once daily with food, indefinite duration. HIV-1: TAF is a component of fixed-dose combinations (e.g., Biktarvy = bictegravir + emtricitabine + TAF; Genvoya; Descovy) — dose set by the FDC, typically 25 mg TAF / day. No renal dose adjustment for CrCl ≥15 mL/min; HD patients can receive 25 mg daily after dialysis on dialysis days. Hepatic: not recommended in decompensated cirrhosis (Child-Pugh B/C — use TDF or entecavir). Abrupt discontinuation in HBV → risk of severe acute exacerbation; monitor LFTs ≥several months after stopping (black-box).
Ukraine registered	True
NSZU reimbursed	True
Ukraine last verified	2026-05-18

Warnings

Lactic acidosis and severe hepatomegaly with steatosis (NRTI class effect; lower signal than TDF)
Severe acute exacerbation of hepatitis B upon discontinuation — monitor LFTs ≥several months post-stop
Risk of HIV-1 resistance in HIV/HBV coinfected patients treated for HBV alone without full ART

Notes

STUB — v0.2 prevention-workstream authoring; pending two-Clinical-Co-Lead signoff per CHARTER §6.1 dev-mode. AASLD-2024 preferred first-line HBV antiviral alongside TDF and entecavir; preferred over TDF in older adults (>60), reduced GFR (CrCl <60), and osteopenia/osteoporosis given the ~90% lower systemic tenofovir exposure. Also a backbone of multiple HIV-1 FDC ART regimens (Biktarvy, Genvoya, Descovy). Long-term HBV suppression is the etiologic-prevention pathway for HBV-mediated HCC and HBV-associated B-cell NHL (the v0.2-A scope). Note: avoid in decompensated cirrhosis — use entecavir or TDF instead (TAF clinical data in decompensated disease are limited). The HIV-ART weight-gain signal vs TDF is well-described but irrelevant to HBV monotherapy at 25 mg/day. Two-Co-Lead signoff queued for v0.2-A clinical review.

Used By

Access Pathways

AP-ART-NSZU-HIV - ART regimens (Biktarvy and alternatives) via НСЗУ HIV programme
AP-ENTECAVIR-NSZU-HBV - Entecavir via НСЗУ HBV programme (reimbursed)
AP-TENOFOVIR-AF-NSZU-HBV - Tenofovir alafenamide (TAF) via НСЗУ HBV programme (reimbursed)

Contraindications

CI-TENOFOVIR-SEVERE-RENAL - CI-TENOFOVIR-SEVERE-RENAL

Regimens

REG-HBV-TENOFOVIR-AF - Tenofovir alafenamide (TAF) — chronic HBV antiviral suppression