What Are the Differences Between TDF and TAF?

December 22, 2019 | Firm News,Mass Torts

Tenofovir disoproxil fumarate (TDF) is an antiretroviral (ARV) medication approved in 2001 to prevent and treat HIV, and in 2008 to treat chronic hepatitis B. Tenofovir alafenamide (TAF) is a new and improved formulation of tenofovir, approved in 2015. Although TDF is the most commonly prescribed ARV, it presents several safety concerns.

What is TDF and How Does it Work?

TDF, tenofovir disoproxil fumarate, is a drug used to help individuals treat, and prevent or reduce the chances of contracting HIV. When used as a preventative method, doctors refer to it as pre-exposure prophylaxis or PrEP. It is also used as treatment for hepatitis B infections. The drug works by blocking the pathways that viruses use to spread infection. HIV, for example, attacks the immune cells that help your body fight infections. Therefore, TDF can possibly prevent that from occurring or slow the spread of the disease, if the medication is already in the bloodstream. TDF is marketed under the names Truvada, Atripla, Complera, Stribild, and Viread by a manufacturer named Gilead Sciences.

What is TAF and How Does it Differ from TDF?

Tenofovir alafenamide (TAF), is being tested as a replacement for TDF. It is a pro-drug that can be absorbed quicker than TDF and can be prescribed in smaller doses, as higher levels of the active drug, tenofovir diphosphate, is seen in the cells. This is the major difference compared to TDF, in that smaller doses means that vital bodily organs, such as the kidneys and bones, are exposed to lower levels of the drug. As a result, the possibility of harmful side effects is reduced. However, results from a meta-analysis published in the Journal of Virus Eradication state that this is only the case when used in an antiretroviral therapy regimen containing a boosting agent. TAF drugs currently on the market go under the names Genvoya, Odefsey, and Descovy.

Safety Concerns with TDF

The published data on TDF use indicates potential side effects of dizziness, nausea, or diarrhea. However, as early as 2001, many patients also began reporting lower bone density, liver problems, or kidney failure after taking the ARV medication. Many people now believe that Gilead may have been complicit in not disclosing these serious potential consequences of TDF use and kept the dangerous product on the market, despite the availability of safer TAF alternatives. The manufacturer is now facing numerous lawsuits by patients who have suffered severe side effects, for failing to inform the public on the dangers of TDF and continuing to sell the drug despite developing an alternative drug that is safer and stronger.

Medications Subjected to Litigation

Gilead is facing litigation for the following types of TDF medications:

• Truvada: the original TDF medication.
• Viread: also goes by the name Tenofovir DF and is used to treat Hepatitis B and HIV.

• Atripla: also goes by the name Efavirenz. It is not used for prevention, but only as HIV treatment.
• Complera: also goes by the name Rilpivirine. It is not for prevention, but only as HIV treatment.
• Stribild: also goes by the names Elvitegravir, Cobicistat, and Emtricitabine. It is not for prevention, but only as HIV treatment.

Find Out More Regarding TDF Lawsuits

To further discuss a potential lawsuit related to a TDF medication, contact the mass tort litigation attorneys from the Dunken Law Firm. We have over two decades of experience holding large companies responsible for their dangerous products. Schedule a free consultation today, we are available online or by calling (713) 554-6780.