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Antiviral — Hepatitis B (Nucleotide Analogue) Pregnancy: Section 4.6, verbatim: 'A large amount of data on pregnant women (more than 1,000 pregnancy outcomes) indicate no malformations or foetal/neonatal toxicity associated with tenofovir disoproxil. Animal studies do not indicate reproductive toxicity. The use of tenofovir disoproxil may be considered during pregnancy, if necessary. In the literature, exposure to tenofovir disoproxil in the third trimester of pregnancy has been shown to reduce the risk of HBV transmission from mother to infant if tenofovir disoproxil is given to mothers, in addition to hepatitis B immune globulin and hepatitis B vaccine in infants. In three controlled clinical trials, a total of 327 pregnant women with chronic HBV infection were administered tenofovir disoproxil (245 mg) once daily from 28 to 32 weeks gestation through 1 to 2 months postpartum ... No safety signal has emerged from these data.' BREAST-FEEDING: 'Generally, if the newborn is adequately managed for hepatitis B prevention at birth, a mother with hepatitis B may breast-feed her infant. Tenofovir is excreted in human milk at very low levels and exposure of infants through breast milk is considered negligible ... In order to avoid transmission of HIV to the infant it is recommended that women living with HIV do not breast-feed their infants.' FERTILITY: limited clinical data; animal studies do not indicate harmful effects. This is tenofovir disoproxil data only - the bundle contains no tenofovir alafenamide pregnancy data.

Tenofovir (TDF/TAF)

Brand names: Viread (TDF), Vemlidy (TAF)

Tenofovir (as the disoproxil or alafenamide prodrug) is a nucleotide reverse transcriptase inhibitor used in hepatology to treat chronic hepatitis B virus infection.

Adult dose

Dose: Chronic hepatitis B - tenofovir DISOPROXIL (TDF): 245 mg (one tablet) once daily, taken orally with food.
Route: Oral, with food
Frequency: Once daily
Verbatim section 4.2: 'Adults and adolescents aged 12 to < 18 years and weighing >= 35 kg: The recommended dose of Tenofovir disoproxil for the treatment of HIV or for the treatment of chronic hepatitis B is 245 mg (one tablet) once daily taken orally with food.' Method of administration: 'Tenofovir disoproxil tablets should be taken once daily, orally with food.' 'Therapy should be initiated by a physician experienced in the management of HIV infection and/or treatment of chronic hepatitis B.' TAF IS NOT COVERED BY THIS SOURCE: the page name advertises tenofovir alafenamide as well, but no TAF SPC was fetched, so no TAF dose is published. 245 mg is a tenofovir disoproxil dose and applies to that salt only. Section 4.4: 'Tenofovir disoproxil should not be administered concomitantly with other medicinal products containing tenofovir disoproxil or tenofovir alafenamide.' A separate TAF SPC must be sourced before any TAF figure appears on this page. maxDose IS DELIBERATELY EMPTY: section 4.2 states no maximum dose - the regimen is a single fixed 245 mg daily dose, and the only quantitative limits in the section are renal dose INTERVALS (see renalAdjustment), which are not ceilings. DURATION IN CHRONIC HEPATITIS B (verbatim, adults and adolescents): 'The optimal duration of treatment is unknown.' In HBeAg positive patients without cirrhosis, 'treatment should be administered for at least 12 months after HBe seroconversion (HBeAg loss and HBV DNA loss with anti-HBe detection, on two consecutive serum samples at least 3 - 6 months apart) is confirmed or until HBs seroconversion or there is loss of efficacy'. In HBeAg negative patients without cirrhosis, 'treatment should be administered at least until HBs seroconversion or there is evidence of loss of efficacy'; discontinuation may also be considered after stable virological suppression for at least 3 years, with serum ALT and HBV DNA followed regularly afterwards to detect late virological relapse. With prolonged treatment beyond 2 years, regular reassessment is recommended. 'In adult patients with decompensated liver disease or cirrhosis, treatment cessation is not recommended.' MISSED DOSE (verbatim): if missed within 12 hours of the usual time, take with food as soon as possible and resume the normal schedule; if missed by more than 12 hours and it is almost time for the next dose, skip it and resume the usual schedule. 'If the patient vomits within 1 hour of taking Tenofovir disoproxil, another tablet should be taken. If the patient vomits more than 1 hour after taking Tenofovir disoproxil they do not need to take another dose.' ELDERLY (verbatim): 'No data are available on which to make a dose recommendation for patients over the age of 65 years.'

Paediatric dose

Route: Oral, with food
Frequency: Once daily
NOT A PER-KILOGRAM DOSE - the SPC gives a single age-and-weight band with a fixed tablet dose, so dosePerKg is null deliberately and no weight calculator runs. Verbatim section 4.2: 'Adults and adolescents aged 12 to < 18 years and weighing >= 35 kg: The recommended dose of Tenofovir disoproxil for the treatment of HIV or for the treatment of chronic hepatitis B is 245 mg (one tablet) once daily taken orally with food.' This is tenofovir DISOPROXIL only. THE FETCHED SPC CONTAINS NO DOSE for children under 12 years or under 35 kg, and none is drafted here. Verbatim: 'The safety and efficacy of tenofovir disoproxil in HIV-1 infected children or children with chronic hepatitis B under 2 years of age have not been established. No data are available.' Renal impairment in children (verbatim): 'The use of tenofovir disoproxil is not recommended in paediatric patients with renal impairment.' BEFORE TREATING AN ADOLESCENT (verbatim): 'The decision to treat paediatric patients (adolescents) should be based on careful consideration of individual patient needs and with reference to current paediatric treatment guidelines including the value of baseline histological information. The benefits of long-term virologic suppression with continued therapy must be weighed against the risk of prolonged treatment, including the emergence of resistant hepatitis B virus and the uncertainties as regards the long term impact of bone and renal toxicity. Serum ALT should be persistently elevated for at least 6 months prior to treatment of paediatric patients with compensated liver disease due to HBeAg positive chronic hepatitis B; and for at least 12 months in patients with HBeAg negative disease.' Verify any under-18 use against a children's formulary.

Dose adjustments

Renal

Tenofovir disoproxil only (no TAF source in this bundle). Section 4.2, adults, verbatim: 'There are limited data on the safety and efficacy of tenofovir disoproxil in adult patients with moderate and severe renal impairment (creatinine clearance < 50 ml/min) and long-term safety data has not been evaluated for mild renal impairment (creatinine clearance 50-80 ml/min). Therefore, in adult patients with renal impairment tenofovir disoproxil should only be used if the potential benefits of treatment are considered to outweigh the potential risks.' MILD (CrCl 50-80 ml/min): 'Limited data from clinical studies support once daily dosing of 245 mg tenofovir disoproxil'. MODERATE (CrCl 30-49 ml/min): if a different formulation is not possible, '245 mg tenofovir disoproxil every 48 hours can be used based on modelling of single-dose pharmacokinetic data ... but has not been confirmed in clinical studies'. SEVERE (CrCl < 30 ml/min): '245 mg tenofovir disoproxil may be administered every 72-96 hours (dosing twice a week)'. HAEMODIALYSIS: '245 mg tenofovir disoproxil may be administered every 7 days following completion of a haemodialysis session' (generally once weekly assuming three sessions per week of approximately 4 hours each, or after 12 hours cumulative haemodialysis). 'No dosing recommendations can be given for non-haemodialysis patients with creatinine clearance < 10 ml/min.' The SPC warns that 'Simulations suggest that the prolonged dose interval using tenofovir 245 mg film-coated tablets is not optimal and could result in increased toxicity and possibly inadequate response' - clinical response and renal function must be closely monitored. PAEDIATRICS: 'The use of tenofovir disoproxil is not recommended in paediatric patients with renal impairment.'

Hepatic

Verbatim section 4.2: 'No dose adjustment is required in patients with hepatic impairment.' The SPC adds: 'If tenofovir disoproxil is discontinued in patients with chronic hepatitis B with or without HIV co-infection, these patients should be closely monitored for evidence of exacerbation of hepatitis.'

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to the active substance or to any of the excipients listed in section 6.1 (this single item is the whole of section 4.3)
  • Section 4.4 warning, not a section 4.3 contraindication: tenofovir disoproxil should not be administered concomitantly with other medicinal products containing tenofovir disoproxil or tenofovir alafenamide
  • Section 4.4 warning, not a section 4.3 contraindication: tenofovir disoproxil should not be administered concomitantly with adefovir dipivoxil
  • Section 4.4 warning, not a section 4.3 contraindication: co-administration of tenofovir disoproxil and didanosine is not recommended
  • Section 4.4 warning: use of tenofovir disoproxil should be avoided with concurrent or recent use of a nephrotoxic medicinal product (e.g. aminoglycosides, amphotericin B, foscarnet, ganciclovir, pentamidine, vancomycin, cidofovir or interleukin-2)

Side effects

  • Renal impairment, renal failure (rare) and proximal renal tubulopathy including Fanconi syndrome (uncommon), sometimes leading to bone abnormalities and infrequently contributing to fractures - renal monitoring is recommended
  • Elevated creatinine and hypophosphataemia reported with use in clinical practice
  • Hepatitis B: approximately one quarter of patients can be expected to experience adverse reactions, most of which are mild; the most frequently occurring reaction in HBV clinical trials was nausea (5.4%)
  • Acute exacerbation of hepatitis has been reported both on treatment and in patients who have discontinued hepatitis B therapy
  • HIV-1: approximately one third of patients experience adverse reactions in combination therapy, usually mild to moderate gastro-intestinal events; approximately 1% of treated adults discontinued treatment because of them
  • Renal function decline observed in trials: after an initial fall of approximately -4.9 ml/min (Cockcroft-Gault) or -3.9 ml/min/1.73 m2 (MDRD) over the first 4 weeks, the annual rate of decline was -1.41 ml/min per year (Cockcroft-Gault) and -0.74 ml/min/1.73 m2 per year (MDRD)
  • Section 4.8 is truncated at the source-fetch limit - the tabulated adverse-reaction list (Table 2) was not retrieved and this list must not be treated as complete

Monitoring

  • Offer HIV antibody testing to all HBV infected patients before initiating tenofovir disoproxil therapy (section 4.4)
  • Calculate creatinine clearance in all patients prior to initiating therapy
  • Renal function (creatinine clearance and serum phosphate) after two to four weeks of treatment, after three months, and every three to six months thereafter in patients without renal risk factors; more frequently in patients at risk of renal impairment
  • If serum phosphate is < 1.5 mg/dl (0.48 mmol/l) or creatinine clearance falls below 50 ml/min in any adult, re-evaluate renal function within one week including blood glucose, blood potassium and urine glucose concentrations; consider interrupting treatment if creatinine clearance is < 50 ml/min or serum phosphate < 1.0 mg/dl (0.32 mmol/l), or in progressive decline of renal function with no other identified cause
  • Serum ALT and HBV DNA regularly after any treatment discontinuation, to detect late virological relapse
  • Close monitoring for exacerbation of hepatitis if tenofovir disoproxil is discontinued in chronic hepatitis B, with or without HIV co-infection
  • With prolonged treatment for more than 2 years, regular reassessment that continuing the selected therapy remains appropriate

Clinical monograph

How it works

Its active form inhibits HBV DNA polymerase (reverse transcriptase), suppressing viral replication and reducing hepatitis B viral load.

Prescribing in practice

  • Stopping treatment can precipitate a severe acute exacerbation of hepatitis, so do not discontinue without specialist supervision and close monitoring of liver function.
  • The disoproxil formulation is associated with renal impairment and reductions in bone mineral density, whereas the alafenamide formulation has a more favourable renal and bone profile.
  • Test for HIV co-infection before starting, as tenofovir-based therapy has implications for HIV management and resistance.

Monitoring

Monitor renal function and, with the disoproxil prodrug, consider bone health, alongside periodic HBV viral load and liver function tests.

Counselling the patient

  • Take it regularly and do not stop without specialist advice, as your hepatitis can flare badly.
  • Attend for blood tests to check your kidneys and the response of your hepatitis.

Evidence & guidelines

Tenofovir is recommended by NICE as a first-line antiviral for chronic hepatitis B with a high barrier to resistance.

Reference: EASL HBV Clinical Practice Guidelines 2017; Marcellin et al. NEJM 2008; WHO HBV Guidelines 2015; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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