In April 2015, when the FDA announced it had approved Kybella (deoxycholic acid, Kythera) as a treatment for adults with moderate-to-severe submental fat, the government agency noted that Kybella can cause serious side effects, including skin necrosis and nerve injury.
“Kybella is a cytolytic drug, which when injected into tissue physically destroys the cell membrane. When properly injected into submental fat, the drug destroys fat cells; however, it can also destroy other types of cells, such as skin cells, if it is inadvertently injected into the skin,” according to the FDA.
The most common side effects of Kybella include swelling, bruising, pain, numbness, redness and areas of firmness, according to the FDA, but nerve injury in the jaw, resulting in an uneven smile or facial muscle weakness and trouble swallowing, is another potential side effect.
Researchers assessed Kybella’s safety in two pivotal phase 3 clinical trials, of 1,019 subjects — 513 were randomized to the Kybella arm; the rest were treated with placebo. In the studies, researchers followed participants for 24 weeks after their last treatments and reported these side effects in the active arms: injection site edema/swelling in 87% of those in the studies; injection site hematoma in 72%, and injection site pain in 70%.
“The vast majority of injection site reactions was described by the investigators as mild to moderate and was considered resolved by the end of the trial,” according to the FDA. “The marginal mandibular nerve injuries in the [Kybella] treatment arm occurred at the 4% rate and dysphagia at 2%. All cases (except one of dysphagia) completely resolved without any treatment.”
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NEXT: Safety in Question?
Safety in Question?
Some question Kybella’s safety, in part, because of previous attempts to use fat dissolving injections.
“… I am skeptical about Kybella. This is the third re-emergence of deoxycholic acid. It first surfaced in the1950s as mesotherapy, then as ‘lipodissolve’ several years ago, and now [it’s] brought out by the giant Allergan,” says Boca Raton, Fla., plastic surgeon Jonathan R. Berman, M.D.
Related: Can Kybella be used to treat fat in areas other than the submental space?
Dermatologist and cosmetic surgeon Joel Schlessinger, M.D., tells Cosmetic Surgery Times he has been using Kybella since 2008. He was in the first clinical trials. Dr. Schlessinger says he finds Kybella easy to use and effective when the properly chosen patient.
“Like any cosmetic procedure, there is a short learning curve, but Kybella seems to have a much easier process to get used to it due to the fact that most dermatologists are so comfortable with the concept of injections for fillers and neurotoxins,” Dr. Schlessinger says.
NEXT: 2 Complications to Avoid
2 Complications to Avoid
The most worrisome complication, according to Dr. Schlessinger, is nerve “stunning” from the deoxycholic acid, which occasionally affects the marginal mandibular nerve if the surgeon isn't careful about where they inject, he says.
“With proper training and careful selection of realistic patients, this is easily avoided,” Dr. Schlessinger says. “If it does occur, so far I haven't heard of any permanent nerve damage and it normally returns to baseline in a month or so.”
The other complication, according to Dr. Schlessinger, comes from poor patient selection and not meeting their expectations.
“Many individuals, some with too much or too little fat, are interested in Kybella,” he says. “While individuals with too little fat might seem fine to inject, the proximity of the area of fat to the nerves sometimes leads to more healing issues and pain. For those with too much fat, they simply don't have results and this can lead to unhappy patients.”
Kybella is easy to blame when results fall short of patient expectations, but the treatment is often not to blame, according to Dr. Schlessinger.
“I have had several situations where patients came back saying that the procedure, whether it be liposuction, Kybella or non-invasive fat treatments, didn't work and repeat weight measurement showed significant weight gain. Having a good weight on record is sometimes worth its weight in gold!” he says.
Related: Submental fat? Making the right treatment choice
Scot Bradley Glasberg, M.D., a New York City plastic surgeon and immediate past president of the American Society of Plastic Surgeons, was recently trained to use Kybella and has since treated patients with it in practice. He says Kythera’s solid research on targeting the submental area and thorough directions for use make him feel confident about the procedure’s safety.
“The whole concept of lipolysis to break down fat has been around and has been tried. [In the past] it was fraught with complications — seromas, burns, unevenness — because you couldn’t control where things were going. So, to Kybella’s credit, they did what I think is a very well thought out, time-consuming, money-consuming study… that looked at it in a very fixated area — the submental area. It ends up if you do the procedure — you probably have to do it two to three times on each patient — you end up with a result that is pretty much equivalent to liposuction.”
NEXT: Follow the Rules
Follow the Rules
Kybella requires training for use, and that’s a good thing, according to Dr. Glasberg.
“There are subtleties to this technique, including where to go; where not to go. You have to make sure you don’t touch a nerve or a vessel,” he says. “Kythera has a nice explanation of the technique. They have this grid for the chin, with where to place the injections and very clear instructions on how to do it. So, once you do the training and you understand it, it’s pretty easy to do. Probably be a little more time consuming but on the equivalent of learning to do Botox.”
Related: Kybella pricing: Do you know how to charge?
The more serious complications documented by the FDA can be avoided, Dr. Glasberg says, with proper training in the technique. By injecting Kybella directly into the fat, according to the grid, surgeons carefully avoid nerves and potential skin issues.
“I think the best way to avoid the complication is literally follow the rules,” he says.
A fear with Kybella use, according to Dr. Glasberg, is that surgeons will use it off label, in the abdomen, flanks and elsewhere.
“I would caution surgeons not to do that because we just don’t know how Kybella will react — how it will diffuse and spread. I think the nice thing about the way Kythera went about it is they took a specific location, like I said in the submental area, where you can control things,” Dr. Glasberg says.
Disclosures: Drs. Bradley and Berman report no relevant disclosures. Dr. Schlessinger is a Kythera researcher.