Certain HIV Meds May Trigger Weight Gain
TUESDAY, March 16, 2021 (HealthDay News) – A commonly prescribed component of life-saving antiretroviral cocktails used to treat HIV may trigger weight gain, new research warns.
The concern stems from the monitoring of patients on antiretroviral therapy (ART). Since the mid-1990s, therapy has relied on various combinations of drugs to essentially thwart HIV, control viral load, and turn a once fatal infection into a manageable disease.
But the new research raises questions about a drug featured in many ART recipes: tenofovir alafenamide, also known as TAF.
There is no doubt that TAF works. The researchers noted that it was both effective and well tolerated. And TAF has grown in popularity in recent years because it poses less of a risk to kidney and bone health than another drug called tenofovir disoproxil fumarate (TDF).
But the new study found that over 18 months, patients on antiretroviral therapy containing TAF gained almost 4 pounds on average, compared to about 1.5 pounds in patients on drug cocktails containing TDF.
According to the results, nearly 14% of normal weight TAF users are overweight or obese, compared to just over 8% of their TDF counterparts.
“TDF and TAF are common parts of these combination drugs and most regimens,” said Dr Michael Horberg, director of the HIV / AIDS and STD division at Kaiser Permanente. “This is why this study is so important.”
Horberg, who was not involved in the study but reviewed the results, pointed out that both drugs are also part of most so-called PrEP regimens. PrEP (pre-exposure prophylaxis)is designed to prevent HIV infections from setting in in the first place, “thus an even greater number of people [are] maybe use it for that, ”he said.
Horberg said the new drug TAF was seen as “the answer” to the main problem with the old drug TDF, which increased creatinine levels in some patients, an indicator of worsened kidney function.
“And, in most cases, it’s true,” Horberg said.
He said the new study is critical, however, because weight gain and worsening lipid levels are “not small problems either.” Lipids are fatty substances that can build up and block arteries.
Most people don’t want to gain weight because of the drugs, “and the increased fat may be associated with cardiovascular disease (heart attacks, strokes), which we also want to prevent in people living with HIV. “said Horberg.
For the study, a team led by Dr Bernard Surial from the University Hospital of Bern in Switzerland, examined weight gain data collected from more than 3,400 Swiss HIV-positive patients between 2016 and 2019.
All had taken an antiretroviral cocktail containing the old TDF for at least six months, before switching to an ARV regimen containing the new drug TAF.
The weight gain among the patients who made the switch was then compared to almost 900 patients who remained faithful to TDF for 18 months of follow-up.
Around this time, researchers found that not only were weight gains much greater in TAF users, but also increases in their cholesterol and triglyceride levels, which may signal an increased risk of heart problems.
Horberg said the results were not surprising.
“Our patients had noticed this weight gain before us,” he said. “And we used to say ‘oh, it’s not the drugs. You just eat more because you are doing better. ‘ Well we now know that is not true. And if they didn’t have kidney problems, maybe we tried to fix a problem that didn’t exist “by switching therapy.
So what does this mean for future treatment options?
“Frankly, it has to be done on a case-by-case basis,” Horberg said.
One consideration is money, he noted, as TDF is now a generic drug and much cheaper than TAF.
“We want everyone to have these drugs, including PrEP,” said Horberg. “But weight gain is a serious problem, and many patients don’t like how it makes them feel or look,” the PrEP takers included.
If the weight gain is due to the drug, they’ll stop taking it, Horberg said, so you have to find a balance. If there are kidney problems, it is important to change. Otherwise, doctors should discuss the pros and cons of any changes with their patients, he suggested.
Dr. Rajesh Gandhi, fellow of the Infectious Diseases Society of America and president of the HIV Medicine Association, also reviewed the results of the study.
“This difference in weight gain is something we pay attention to because we try to keep people healthy for decades, not years,” Gandhi said.
The drugs that revolutionized HIV treatment in the mid-1990s did get the virus under control, but they do not eliminate it. This means that once a patient starts taking ARV drugs, it continues for the rest of their life, making side effects a concern, he explained.
“Today there are a lot less side effects than when ART first came into the picture,” Gandhi said. “And the weight gain seen among those who took the new formulation of tenofovir was relatively small. And not everyone was affected. But there was a difference.”
For patients with borderline kidney disease or osteoporosis, the new formula has many benefits, Gandhi said, adding that more research into weight gain issues is needed.
In the meantime, decisions about which formulation to use should be based on discussion with each patient’s health care provider “and decided on a case-by-case basis,” he said.
The study was published online on March 16 in the Annals of Internal Medicine.
Learn more about antiretroviral therapy at the U.S. National Institutes of Health.
SOURCES: Michael Horberg, MD, MAS, director, HIV / AIDS and STDs, Kaiser Permanente and Care Management Institute, Rockville, Md .; Rajesh Gandhi, MD, president and member, Infectious Diseases Society of America, and president, HIV Medicine Association; Annals of Internal Medicine, March 16, 2021, online
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