Pharmacology · Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs)

Tenofovir disoproxil !

A prodrug of tenofovir, the most widely used antiretroviral. It treats HIV and hepatitis B and prevents HIV; kidney and bone need watching.

Updated 2026-11-01

Class: Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs)
Enzyme: HIV-1 reverse transcriptase
ATC code: J05AF07
WHO Model List of Essential Medicines

Also called: TDF, tenofovir disoproxil fumarato

HIV-1 reverse transcriptaseTenofovir disoproxil

The figure shows tenofovir diphosphate, the active form, as the incoming nucleotide in HIV-1 reverse transcriptase bound to its DNA template.

Target in 3D: HIV-1 reverse transcriptase. PDB structure 1T05 (RCSB PDB, public domain). View the structure at RCSB PDB

Mechanism of action

A nucleotide analogue (it already carries a phosphate). It is hydrolysed to tenofovir, and cellular kinases turn it into tenofovir diphosphate, which competes with dATP; incorporated into viral DNA, it ends the chain because its sugar ring is incomplete. It also blocks the hepatitis B virus polymerase.

It is hydrolysed to tenofovir and phosphorylated to the diphosphate
It competes with dATP at reverse transcriptase
Its incomplete ring ends the viral DNA chain

Pharmacokinetics

Absorption: Oral tenofovir bioavailability about 25% when fasting; higher with a high-fat meal
Elimination: By the kidney (filtration and tubular secretion); it builds up in kidney failure
Half-life: Plasma terminal half-life of tenofovir about 17 hours

Indications

HIV-1 infection, combined with other antiretrovirals HIV infection and AIDS →
Chronic hepatitis B Viral hepatitis →
HIV pre-exposure prophylaxis (PrEP), alone or with emtricitabine HIV infection and AIDS →

Adverse effects

Common

Nausea, diarrhoea
Headache
Tiredness
Rash

Contraindications

The label lists no absolute contraindications; it is avoided with nephrotoxic drugs and in kidney failure without adjustment

Key interactions

High-dose or multiple NSAIDs, and other nephrotoxic drugs: Higher risk of kidney failure
Atazanavir: Tenofovir lowers atazanavir: atazanavir is given boosted with ritonavir
Ritonavir or cobicistat: They raise tenofovir concentrations by inhibiting kidney transporters

What is monitored

HIV and hepatitis B tests before starting
Creatinine, creatinine clearance, urine glucose and protein
Phosphate in people at renal risk
Bone density if there are prior fractures or osteoporosis risk

Administration and safety

By mouth
Do not confuse tenofovir disoproxil with tenofovir alafenamide: they are different prodrugs and are not swapped without an explicit order
Check fixed-dose combinations that already contain tenofovir so it is not duplicated

Nursing care

Check kidney function before and during treatment
Ask about over-the-counter anti-inflammatory use
Teach to report bone pain, muscle weakness or urine changes
Explain that in PrEP protection depends on adherence and regular HIV tests

Pregnancy and breastfeeding

Antiretroviral treatment in pregnancy protects the mother and lowers HIV transmission to the baby; the treating team chooses the regimen.

Test yourself

Think of the answer, then tap the question to see it.

Which typical kidney lesion does tenofovir disoproxil cause?

Proximal tubulopathy (Fanconi syndrome): loss of phosphate, glucose and protein in urine; it can lead to osteomalacia.

Why is hepatitis B serology done before starting tenofovir?

Because it also suppresses hepatitis B: if the person has it and stops the drug, a severe flare can follow.

How does tenofovir differ structurally from other NRTIs?

It is a nucleotide analogue: it already carries a phosphate, so it needs one fewer phosphorylation step.

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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: DailyMed - TENOFOVIR DISOPROXIL FUMARATE tablet (DailyMed (U.S. National Library of Medicine), 2026); Tenofovir disproxil fumarate: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2025); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 64 (McGraw Hill, 2023).

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Representative model, for educational purposes only.