The U.S. Food and Drug Administration approved Botox (onabotulinumtoxin A) to treat spasticity in the flexor muscles of the elbow, wrist, and fingers in adults. Spasticity is common after stroke, traumatic brain injury, or the progression of multiple sclerosis.

"Muscles affected by spasticity have increased stiffness and tightness, which may lead to pain, difficulties with hygiene and other activities of daily living, and may affect how a patient looks," said Russell Katz, M.D., director of the Division of Neurology Products in the FDA's Center for Drug Evaluation and Research. "In clinical trials, treatment with Botox was found to be beneficial to patients with upper limb spasticity."

Botox works by temporarily blocking the connections between nerves and muscles, resulting in a temporary paralysis of the spastic muscle.

Botox has a Boxed Warning that says the effects of the botulinum toxin may spread from the area of injection to other areas of the body, causing symptoms similar to those of botulism. Those symptoms include swallowing and breathing difficulties that can be life-threatening.

The most common adverse reactions reported by patients with upper limb spasticity were nausea, fatigue, bronchitis, muscle weakness, and pain in the arms.

Botox has not been shown to be safe and effective treatment for other upper limb muscles, spasticity in the legs, or for treatment of fixed contracture - a condition that affects range of motion. Treatment with Botox is not intended to substitute for physical therapy or other rehabilitative care.

Botox is manufactured by Allergan Inc. of Irvine, Calif.

Source
U.S. Food and Drug Administration