What is TDF?
Tenofovir disoproxil fumarate (or TDF) is a medication used to treat HIV-positive patients, as well as a prophylactic to decrease the chances of contracting HIV from another person.
TDF medications have helped people live longer, more productive lives as it helps keep the HIV at bay. To this day, there is no known cure for HIV. TDF medications are necessary for those with HIV to ease living with the virus.
Manufactured by biotechnology company Gilead Sciences, the Food and Drug Administration initially cleared TDF for use for the public in 2001 under the brand name Viread.
TDF wasn’t a popular method at first, as it was initially only administered intravenously. However, Gilead developed an oral version of the medication and quickly dominated the market.
It’s not only used to treat HIV, but can be used to treate Hepatitis B (HBV) as well. When used as a prophylactic, known as a pre-exposure prophylaxis (or PrEP), it helps prevent HIV infection. This is known as antiretroviral therapy (ART).
Known as a nucleoside reverse transcriptase inhibitor (NRTI), TDF works by reversing the enzyme that blocks HIV. It prevents the enzyme from multiplying and killing off cells used to fight infection.
TDF may help reduce the amount of HIV in a person’s body and works similarly for those with Hepatitis B, but it is not a cure. The end result of untreated HIV is AIDS, where the body can no longer produce cells that fight off against cancer and infection.
Gilead is accused of intentionally misrepresenting and downplaying the safety of TDF medications, while also withholding a safer medication from the public.
Gilead announced near the end of its TDF patent that the company had formulated a new medication known as tenofovir alafenamide fumarate (or TAF). This medication was approved by the Food and Drug Administration in 2015 and sold under the brand name Genvoya.
Amid these side effects, Gilead had been sitting on TAF for years before they applied for FDA approval– and before its patent for TDF ran out.
In an LA Times article from 2016, Tim Horn of the Treatment Action Group (which advocates for AIDS patients) said, “That’s a decade of potentially avoidable kidney and bone toxicity.”
Gilead has put thousands of patients at risk of serious side effects that can affect their quality of life.
Shortly after it was introduced on the market, the FDA slapped Gilead with a warning letter about its marketing practices. The agency told Gilead to stop making “misleading and illegal statements” about Viread that had been discussed at an Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC).
Linda Pinock, the regulatory review officer of the FDA’s Division of Drug Marketing, Advertising, and Communications (DDMAC) said the FDA “identified promotional activities that are in violation of the Federal Food, Drug and Cosmetic Act and its implementing regulations.”
A Gilead company representative apparently bragged Viread had “no toxicities”, and was both “extremely safe” and “extremely well-tolerated.” The FDA describes these kind of statements as false or misleading.
Mounting lawsuits against Gilead
In 2019, 41 patients from across the country filed a personal injury lawsuit against Gilead. The legal fees were covered by AIDS Healthcare Foundation but the organization will not receive any additional funding in excess of its cost.
In the lawsuit originating in California, the plaintiffs claim the company failed to warn that its medications caused serious side effects and that it intentionally delayed releasing a medication that was stronger and safer than TDF.
So, how safe was this newer medication? One animal study showed that TAF had a “thousand-fold greater activity against HIV” than TDF. Read more about the dangers of TDF in the studies outlined below.
In one of the personal injury lawsuits, it states:
“Gilead had a duty to share its exclusive knowledge of the risks associated with TDF. Gilead failed to do this. Instead, Gilead misrepresented the safety and benefits of TDF and failed to provide prescribing physicians and their patients with the information they needed to safely and reasonably prescribe and take Gilead’s drugs.”
As well as:
“… studies showed that TAF was far less toxic and confirmed that TDF’s low absorption, high dosage, and potential bone and renal toxicity were real risks. But, Gilead did not publish this research, did not conduct clinical trials of TAF, did not change its prescribing information, and did not instruct its sales representatives to begin informing doctors that the toxicities associated with TDF could be eliminated with a new, better drug.”
In an annual financial disclosure from 2018, Gilead addressed the personal injury lawsuits it is up against.
“We intend to vigorously defend ourselves in these actions. While we believe these cases are without merit,
we cannot predict the ultimate outcome. If plaintiffs are successful in their claims, we could be required to pay significant monetary damages.”
–Gilead 2018 Financial Report
There are multiple studies available that have measured the propensity for bone and kidney failure from TDF use. These are the same issues claimants in lawsuits against Gilead have suggested kept them sick while the company withheld TAF from the public.
- This study stated:
“TDF has a small but definite negative impact on kidney function..”
- This study evaluated the effect of TDF on the kidneys in patients with chronic hepatitis B.
“Renal function was decreased from baseline in CHB patients receiving TDF therapy, which indicates that the renal function of patients undergoing treatment with TDF should be monitored regularly.”
- This study investigated bone loss with TDF use.
“Clinical observations have revealed a strong correlation between loss of bone density in HIV-infected individuals, particularly in conjunction with the antiretroviral drug tenofovir.”
- This study points out that TAF has less kidney and bone side effects than TDF.
“Off-target renal and bone side effects may occur with tenofovir disoproxil fumarate (TDF) use. Compared with TDF, tenofovir alafenamide (TAF) results in significantly reduced plasma tenofovir (TFV) and may have less renal and bone toxicity.”
- This study said TDF contributes to low bone mineral density (BMD).
“The etiology of low BMD in HIV infection is multifactorial (3, 4), but antiretroviral toxicity, in particular from tenofovir disoproxil fumarate (TDF), contributes significantly.”
TDF Side Effects
Gilead has faced ongoing issues from its marketing and advertising communications, to lawsuits over TDF’s side effects.
When HIV-positive people take HIV-inhibiting medications like TDF, they are supposed to be able to live longer and fuller lives. However, as you have already read, there are dangerous side effects when it comes to TDF use, as outlined below.
According to AIDS Info, liver problems are associated with TDF medications. They can appear as:
- Yellowing of your skin or the whites of your eyes (jaundice)
- Dark-colored urine
- Light-colored bowel movements
- Loss of appetite for several days or longer
- Feeling sick to your stomach (nausea)
- Pain in the stomach area (abdominal pain)
TDF may also cause lactic acidosis, a buildup of lactic acid in the blood. If left untreated, lactic acidosis can be fatal. The warning signs may include:
- Weakness or tiredness
- Unusual muscle pain
- Shortness of breath or fast breathing
- Stomach pain with nausea and vomiting
- Hands or feet that feel cold or turn blue
- Dizziness or lightheadedness
- Fast or abnormal heartbeat
Additional side effects from medications containing TDF are:
- Chronic kidney disease
- Declining kidney function
- Acute kidney injury
- Acute renal failure
- Fanconi syndrome
- Kidney failure
- Decreased bone mineral density
- Osteopenia (softening, or thinning of the bones)
- Bone fractures
- Dental problems
- Tooth loss or decay
It’s very important to take your medication as prescribed. It is possible to have a flare-up of HIV if you stop taking your medication as prescribed. Even if you’re reading this and know you have been seriously affected by any one of these HIV medications, it’s important you speak with your physician before you stop taking TDF medications.
Gilead primarily produces HIV medications and in 2018 alone, raked in over $14 billion in profits. Below are a list of TDF-containing medications manufactured by Gilead that our law firm is actively filing lawsuits on. All of these medications have been linked to the above mentioned side effects.
Viread was the first TDF medication that Gilead put on the market after FDA approval in 2001.
Truvada was approved by the Food and Drug Administration in 2004. It is a combination of TDF and emtricitabine.
Atripla is a combination medication of efavirenz, emtricitabine, and TDF. It was approved by the FDA in 2006.
Stribild is a combination medication of elvitegravir, cobicistat, emtricitabine and TDF. It was approved by the FDA in 2012.
Complera was most recently approved by the FDA in 2016. It is a combination medication of emtricitabine and rilpivirine.
As with any conversation surrounding HIV and AIDS, it’s important to remember HIV prevention strategies. According to the Centers for Disease Control and Prevention, abstinence (not having sex), limiting the number of sexual partners, never sharing needles, and using condoms the right way every time you have sex, and practicing antiretroviral therapy (ART) for those that are HIV-positive are all ways to keep you and your community safe.