According to the PREEMPT injection paradigm, 5 units of onabotulinumtoxinA is to be administered to two sites on each side for a total dose of 20 units across four sites in the cervical paraspinal muscle group near the midline. The first injection site is approximately 1 cm left of the midline of the cervical spine and approximately 3 cm (2 fingerbreadths) inferior to the occipital protuberance. The second site is measured approximately 1 fingerbreadth diagonally up at a 45° angle from the first injection. The injections should be administered in the most superficial aspect of the muscle, angling the needle 45° and superiorly. To aid in the placement of the injections, the patient should be positioned upright with the head in a neutral position. If the neck is flexed too far forward, injections may be too deep. Injections that are too low or too deep in this muscle group can lead to muscle weakness and neck pain. Injectors should use a suboccipital approach to ensure that the injection sites are not too low. In addition, a horizontal line can be visualized across the neck, approximately 2 fingerbreadths down from the occipital protuberance, to make certain the injections remain above the line and are not administered too low in the neck. The higher these injections are, the more likely that they will be in the muscle fascial condensation, which will minimize the potential for neck weakness. These injections should not be done below the hairline. Patients who have trigger points in the neck should not be injected at these sites as these are generally areas where muscles may be weakened and injections of onabotulinumtoxinA at these sites might worsen their neck issues.
Richard Clark, a plastic surgeon from Sacramento (CA), was the first to document a cosmetic use for botulinum toxin. He treated forehead asymmetry caused by left sided forehead nerve paralysis that occurred during a cosmetic facelift. Since the injured nerve could possibly regenerate by 24 months, a two-year waiting period was necessary before definitive surgical treatment could be done. Clark realized that botulinum toxin, which had been previously used only for cross eyed babies and facial tics, could also be injected to smooth the wrinkles of the right forehead to match her paralyzed left. He received FDA approval for this cosmetic application of the toxin and successfully treated the person and published the case study in 1989.
Do not receive BOTOX® Cosmetic if you: are allergic to any of the ingredients in BOTOX® Cosmetic (see Medication Guide for ingredients); had an allergic reaction to any other botulinum toxin product such as Myobloc® (rimabotulinumtoxinB), Dysport® (abobotulinumtoxinA), or Xeomin® (incobotulinumtoxinA); have a skin infection at the planned injection site.