The Food and Drug Administration (FDA) has expanded the approval of Botox® (onabotulinumtoxinA) to include 8 new muscles for the treatment of upper limb spasticity in adults, along with the use of ultrasound as a muscle localization technique in adult spasticity.

The indication for adult upper limb spasticity treatment now includes elbow and forearm muscles (brachialis, brachioradialis, pronator teres, and pronator quadratus), intrinsic hand muscles (lumbricals and interossei) and thumb muscles (flexor pollicis brevis and opponens pollicis). 

Dosing of Botox should be individualized based on the size, number and location of muscles involved, severity of spasticity, the presence of local muscle weakness, the patient’s response to previous treatment, and adverse event history. Localization of the involved muscles with techniques such as needle electromyographic guidance, nerve stimulation, or ultrasound is recommended.

The most common adverse reactions reported in adult patients with upper limb spasticity include nausea, fatigue, bronchitis, pain in extremity and muscular weakness.

Botox is supplied as 100 Units and 200 Units of vacuum-dried powder in single-dose vials for reconstitution.


FDA approves expanded Botox® (onabotulinumtoxinA) label to include eight new muscles to treat adults with upper limb spasticity. News release. AbbVie. Accessed July 29, 2021.