Key Parameters for the Use of AbobotulinumtoxinA in Aesthetics: Onset and Duration

Abstract

Time to onset of response and duration of response are key measures of botulinum toxin efficacy that have a considerable influence on patient satisfaction with aesthetic treatment. However, there is no overall accepted definition of efficacy for aesthetic uses of botulinumtoxinA (BoNT-A). Mechanical methods of assessment do not lend themselves to clinical practice and clinicians rely instead on assessment scales such as the Frontalis Activity Measurement Standard, Frontalis Rating Scale, Wrinkle Severity Scale, and Subject Global Assessment Scale, but not all of these have been fully validated. Onset of activity is typically seen within 5 days of injection, but has also been recorded within 12 hours with abobotulinumtoxinA. Duration of effect is more variable, and is influenced by parameters such as muscle mass (including the effects of age and sex) and type of product used. Even when larger muscles are treated with higher doses of BoNT-A, the duration of effect is still shorter than that for smaller muscles. Muscle injection technique, including dilution of the toxin, the volume of solution injected, and the positioning of the injections, can also have an important influence on onset and duration of activity. Comparison of the efficacy of different forms of BoNT-A must be made with the full understanding that the dosing units are not equivalent. Range of equivalence studies for abobotulinumtoxinA (Azzalure; Ipsen Limited, Slough UK/Galderma, Lausanne CH/Dysport, Ipsen Biopharm Limited, Wrexham UK/Galderma LP, Fort Worth, TX) and onabotulinumtoxinA (Botox; Allergan, Parsippany, NJ) have been conducted, and results indicate that the number of units of abobotulinumtoxinA needs to be approximately twice as high as that of onabotulinumtoxinA to achieve the same effect. An appreciation of the potential influence of all of the parameters that influence onset and duration of activity of BoNT-A, along with a thorough understanding of the anatomy of the face and potency of doses, are essential to tailoring treatment to individual patient needs and expectations.

Botulinum toxin application in facial esthetics and recent treatment indications (2013-2018)

“…The cosmetic indications such as crow's feet, vertical and horizontal frown, wrinkles on the nose, upper lip rhytids, nasolabial fold, horizontal and vertical neck bands, scar management, and pebbly chin. [715161718192021222324252627282930313233343536373839404142] The noncosmetic indications are migraine, strabismus, hemifacial spasm, bruxism, blepharospasm, spasmodic torticollis, postfacial nerve palsy synkinesis, hyperhidrosis, and esophageal achalasia. [434445464748]…”

“…The dose required for cosmetic use has been discussed and established independently by many researchers based on their experiences[2223242526272829303132333435363738394041] [Table 1]. Review of literature provides more information on dosage preferences by practitioners.…”

“…[23] Slow insertion during injection significantly reduces the pain perception by minimizing mechanical stimulation. [2728] Few authors reconstitute with lidocaine, but the efficacy of BT-A has not been tested. [8] Postinjection, the patient should be asked to press on the site of injection with a tissue which minimizes bruising.…”

Botulinum neurotoxin formulations: overcoming the confusion

“… 49 – 51 Muscle atrophy and reduced number of BoNT-A targets available are thought to be related to the prolonged effect. 44 Dolly and Aoki reported that there is no atrophy of the nerve endings upon blockade of neurotransmitter. 52 Rogozhin et al reported that repeated exposure to BoNT-A results in delayed restoration of neuromuscular transmission back to normal.…”

“…Poor response to the treatment could be due to insufficient or incorrect dosing, errors in drug handling during preparation or storage or administration, and anatomical variations. 44 …”