Chemical structure of Deoxycholic acid:
Mechanism Of Action: —Deoxycholic acid is an endogenous bile acid that solubilizes dietary fat in the gut.1 Kybella contains synthetically derived deoxycholic acid. When the drug is injected into subcutaneous fat tissue, it solubilizes lipids in adipocyte membranes. The resulting cytolysis induces an inflammatory response that clears cell debris.2.
Clinical Studies: — Approval of deoxycholic acid was based on the results of two unpublished, randomized, placebo-controlled trials (REFINE-1 and REFINE-2), which are summarized in the package insert. A total of 1,022 healthy adults 19-65 years old with a BMI ≤40 kg/m2 and moderate to severe submental fullness (grade 2 or 3 on a scale of 0 to 4) were randomized to a maximum of 6 treatment sessions with deoxycholic acid or placebo. The mean age was 49 years, mean BMI was 29 kg/m2, and 85% of the subjects were women. In the two trials, a 2-grade improvement on a composite of clinician and patient ratings of submental fat 12 weeks after the final treatment occurred in 13.4% and 18.6% of patients treated with deoxycholic acid, and in <0.1% and 3.0% of those treated with placebo. A 1-grade composite response also occurred in more patients treated with the active drug (70.0% and 66.5% vs 18.6% and 22.2% with placebo). Significantly more patients treated with deoxycholic acid had a ≥10% reduction in submental fat measured by MRI.
Adverse effects: — The most common adverse effects of Kybella injections, occurring in at least 20% of patients and at a higher rate than with placebo, were edema, bruising, pain, numbness, erythema, and induration at the injection site, which sometimes lasted for more than 30 days. Marginal mandibular nerve injury (asymmetric smile, facial muscle weakness) occurred in 4% and dysphagia occurred in 2% of patients treated with the drug; all but one case resolved without treatment.
Kybella does tend to bruise more than fillers. It is difficult to hold pressure as it is a large area and it would be quite uncomfortable to have pressure held against hyoid bone or throat area. Inject with a 30 gauge half inch long needle for less bruising.
Before treatment following history to be asked to the patients:
1)Any infection in or around the area to be treated
2)Any History of surgery or other cosmetic treatments on neck, chin or face
4)A thyroid disorder
5)swollen lymph nodes
7)A bleeding or clotting disorder such as haemophilia
Klybella is not approved for use by anyone younger than 18 years of old.
Pregnancy: — There are no adequate studies of Kybella in pregnant women. In animal studies, no fetal harm was observed in rats at doses up to 5 times the maximum recommended human dose, but an increased incidence of missing intermediate lung lobe was found in rabbit fetuses at doses 2-fold higher than the maximum recommended human dose.
Dosage and Administration —
· 0.2 ml injections speaced 1 cm apart until all sites in the planned treatment area have been injected.
· Each 2-mL vial of Kybella contains 20 mg of deoxycholic acid.
· Up to fifty injection or 10 ml can be given in a single treatment.
· Upto six single treatment can be administrated at interval no less than one month apart.
The safe and effective use of Kybella depends on the use of correct number and locations for injections proper needle placement and administration techniques.Avoid injection near the area of the marginal mandibular nerve.(A motor branch of facial nerve) Injury to the nerve presents as an asymmetrical smile due to paresis of lip depressor muscles.
How to avoid injury to the marginal mandibular nerve:
1)Do not inject above the inferior border of the mandible.
2)Do not inject within a region defined by a 1-1.5 cm line below the inferior border(From the angle of mandible to the mentum.)
3)Inject Kybella only within the target submental fat treatment area(see fig1 and fig.3)
Injecting into the treatment area:
Use of ice/cold packs , topical and /or injectable local anesthesia may enhance patient comfort.Outline the planned treatment area with a surgical pen and apply a 1 cm injection grid to mark the injection site. (Figure 2 and 3)
Do not inject Kybella outside the defined parameters.
Limitations: The safe and effective use of deoxycholic acid for the treatment of subcutaneous fat outside the sub mental region has not been established and is not recommended yet.Safety and effectiveness have not been established below 18 and above 65 years of age..
Deoxycholic acid is contraindicated in the presence of infection at the injection sites.
Newer RF devices with deeper penetration into sub cutis will accomplish some fat reduction in neck and jaws. But upcoming this new therapy molecule may help clients to reduce the appearance of double chin. More data are awaited about this treatment. There is some issue of nerve damage if used incorrectly with this treatment, so we wish more clinical trial and find better usage of this technique to give good appearance of double chin.
2. B Ascher et al. Efficacy, patient-reported outcomes and safety profile of ATX-101 (deoxycholic acid), an injectable drug for the reduction of unwanted submental fat: results from a phase III, randomized, placebo-controlled study. J Eur Acad Dermatol Venereol 2014; 28:1707.