One of the drawbacks of Botulinum Toxin (BTx) is the need for repeated injections. However, studies on a new formulation indicate that it may have longer-lasting effects, requiring fewer injections and trips to the doctor’s office.
BTx is a nerve poison (neurotoxin) that paralyzes muscle by interfering with the nerve cell’s ability to induce muscle contraction. BTx prevents the release of acetylcholine, a neurotransmitter that triggers muscle contraction, causing a loss of muscle tone and smoothening of wrinkle. The main drawback of BTx is that the effects aren’t permanent—the toxin will eventually be cleared by the body, allowing the muscles to regain contractibility. For the patient, this means going back to the clinic for more injections; current doses usually last 3-4 months on the average.
A newer formulation under study may increase the duration of these effects. While the BTx molecule is similarly present, daxibotulinum Toxin A differs from the existing injectables (onabotulinumtoxin A) in that the attaching protein chain (the Daxi) offers greater distribution into the neuro-muscular junction. Greater distribution may potentiate BTx’s paralyzing capacity.
Canadian clinicians and researchers recently concluded a large trial comparing the newer formulation to currently available treatments for glabellar (between the eyebrows) or forehead lines. Over 250 subjects in9 centres across Canada were enrolled in the study and given BTx injections. Both the patient and the clinician were unaware of which formulation was used, and the results were subsequently evaluated for efficacy, safety and duration of action.
The results, published online in the Journal of Dermatologic Surgery, revealed that the clinical outcomes were indeed comparable. The formulations were equally effective at reducing forehead wrinkles or lines. However, the newer BTx formulation had a longer duration of action averaging 24 weeks, 5 weeks longer than the 19 week average of the traditional formulation. These promising results have led to further research and phase three trials that will assess efficacy and safety in larger populations. If approved for use, fewer injections and trips to the clinic will be needed to treat a wrinkly forehead.