Following absorption, TDF is converted to free tenofovir and then phosphorylated intracellularly by host enzymes to tenofovir diphosphate. TDF is highly effective, but its use is associated with bone, endocrine, and renal toxicity.
The mechanism(s) by which TDF causes these organ-specific toxicities is unclear. There is a complex interplay between bone, endocrine, and renal physiology (Table 1).
1. A lot of people report kidney and bone issues with Tenofovir Disproxil Fumarate (TDF). Its supposed to be low but Ive seen a lot of members report it.
2. Both etv and tdf have to be processed through renal tubes so both can impact kidneys but most people are ok. The Tenofovir TAF is supposed to be very good.
3. Entecavir in high doses in animal studies was causing cancer but no human cases reported yet.
4. Tenofovir has a stonger resistsnce profile for mutants.
It is only more potent in the sense that as a prodrug of Tenofovir, just like the existing Viread(TDF), TAF converts to Tenofovir mainly in the liver cells, therefore has less side effects. But as Stef2011 stated, they reduced the dosage of TAF accordingly, so the same amount of Tenofovir is delivered to the liver cells as TDF. It would be really nice if they can do a proper dosage study of TAF/TDF specifically for HBV (and not use the same dosage for HIV/AIDS).
To evaluate amino acid changes within HBV pol/RT after up to 240 weeks of tenofovir disoproxil fumarate (TDF) treatment and determine their potential association with resistance to TDF. No TDF resistance has been detected through 192 weeks of TDF treatment. Methods: Patients in Studies GS-US-174-0102 (HBeAg-) and GS-US-174-0103 (HBeAg+) were randomized 2:1 to receive TDF or adefovir dipivoxil (ADV) for 48 weeks followed by open-label TDF.
so we have to look carefully at these points since the new formula changes exactly the way cells manage tdf we have to be 100% sure it improves resistance profile over tdf
i also dont like the use of lower levels of the drug, i hope the will concentrate on the use of higher levels of drugs in tissues with no toxicity otherwise the resistance profile might worsen
this is a sure alternative on those with such bad kidneys toxicity to discontinue tdf
hope new trisl will focus on higher levels and
Members the first line oral anti viral for hepatitis b is tenofovir and according to doctor it is long life use. My question are 1) what is the efficacy and safety of tenofovir for says 10years or 15 years or 20years ? 2) what is the longest years of taking tenofovir that we have on record now?
GILD) files its New Drug Application (NDA) with the FDA seeking clearance of tenofovir alafenamide (TAF) 25 mg for the treatment of adults with chronic HBV infection. The company is transitioning its product line to TAF from TDF (tenofovir disoproxil fumarate) because it is just as effective at a dose less that one tenth that of TDF and is less stressful on the bones and kidneys.
The company intends to file its TAF Marketing Authorization Application (MAA) in Europe this quarter.
I remained hbeag positive throughout the 5 years. My question is, with the new tdf around the corner. Considering it might be less toxic. I am now of course feeling the rebound of hbv when not taking virals. Should I get back on tdf? Is it worth staying off tdf until the new one is released? I just want some opinions from the pros. And am I putting myself at risk for hcc. Is it worth it considering promising drugs are surfacing and it looks as if by 2020 well have something.
If presented results are true, it is clear that for hbeag negative CHB, TAF seems to be superior option compared to TDF. Compared to TDF, TAF resulted in significantly higher percentage of patients having normalised ALT after 48 weeks of treatment (50% vs 32%), significantly less loss of eGFR (loss of 1.4 vs 4.7), and significanlty less loss of bone mineral density.
The study is continuing for another 48 weeks...
Tenofovir alafenamide (TAF), a new formulation that reaches higher levels in cells but allows for lower dosing, was as effective as the current tenofovir disoproxil fumarate (TDF) formulation but had less impact on markers of kidney function and bone turnover, researchers reported at the 53rd Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC 2013) this week in Denver.
2 years LDT vs LAM in decompensated patients (n=232); prospective LDT roadmap study with tenofovir (TDF) add-on (n=105). Renal function was assessed at baseline (BL), Week 52 (W52), W104 and W208.
Conclusion
Compensated and decompensated CHB pts receiving telbivudine or telbivudine plus tenofovir have a reliable improvement in renal function. Additional studies will help to understand the mechanism of this protective effect.
TNF more potent.
That is the basis of vireads nephrotoxicity inclination, sinde Viread , which is tenofovir disoproxil fumarate ( TDF), falls apart rapidly in plasma, producing pure tenofovir, that goes to the kidney and is picked up there.
Nevertheless, while still intact, enough TDF enters the liver cells, where is it finally converted in several steps to tenofovir diphosphate, which is the actual substance that inhibits the viral polymerase.
58±16 years) who started therapy with TDF 300mg daily between 2008 and 2011 have been included. TDF has been given for a mean of 32±15 months. Of the 137 patients, 69 were naive to NAs (Group A), while 68 had been exposed to other NAs (lamivudine resistance: 59, telbivudine resistance: 6, other: 3) (Group B). TDF was given as monotherapy in group A and in combination with lamivudine, at least during the initial period, in group B patients.
Good news. It is just starting and will last for 1 month. Hopefully, Phase 2 can start soon after. Thanks.
Tenofovir (TDF) should be the right choice, as it has a better profile of resistance than Adefovir (ADV).
TDF is a well know drug commonly used for HIV treatment. And its indication for HCV infection is more recent than ADV. Even though there is lesser experience with TDF, there is no resistance documented after 3 years of treatment. With ADV, there is documented resistance.
Four years ago, your father would have passed from Telbivudine to Adefovir right away.
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for 3 months i had iches, irritation my Dr said it was bc i stopped, then gradually my body got use to 