Editing Botulinum toxin (section)

===Other muscle disorders===
[[Strabismus]], otherwise known as improper eye alignment, is caused by imbalances in the actions of muscles that rotate the eyes. This condition can sometimes be relieved by weakening a muscle that pulls too strongly, or pulls against one that has been weakened by disease or trauma. Muscles weakened by toxin injection recover from paralysis after several months, so injection might seem to need to be repeated, but muscles adapt to the lengths at which they are chronically held,<ref>{{cite journal |vauthors = Scott AB |title = Change of eye muscle sarcomeres according to eye position |journal = Journal of Pediatric Ophthalmology and Strabismus |volume = 31 |issue = 2 |pages = 85–88 |year = 1994 |pmid = 8014792 |doi = 10.3928/0191-3913-19940301-05 }}</ref> so that if a paralyzed muscle is stretched by its antagonist, it grows longer, while the antagonist shortens, yielding a permanent effect.<ref>{{cite book |vauthors=Simpson L |url=https://books.google.com/books?id=fIwBX6oBDCMC&q=strabismus%20paralyzed%20muscle%20is%20stretched%20the%20antagonist%20shortens%20permanent&pg=PA400 |title=Botulinum Neurotoxin and Tetanus Toxin |date=2 December 2012 |publisher=Elsevier |isbn=978-0-323-14160-4 |access-date=1 October 2020 |archive-date=28 August 2021 |archive-url=https://web.archive.org/web/20210828010046/https://books.google.com/books?id=fIwBX6oBDCMC&q=strabismus+paralyzed+muscle+is+stretched+the+antagonist+shortens+permanent&pg=PA400 |url-status=live }}</ref>

In January 2014, botulinum toxin was approved by UK's [[Medicines and Healthcare products Regulatory Agency]] for treatment of restricted ankle motion due to lower-limb spasticity associated with stroke in adults.<ref name="DDD" /><ref>{{cite web |url=https://www.thepharmaletter.com/article/uk-s-mhra-approves-botox-for-treatment-of-ankle-disability-in-stroke-survivors |title=UK's MHRA approves Botox for treatment of ankle disability in stroke survivors |website=The Pharma Letter |access-date=16 March 2020 |archive-date=27 July 2020 |archive-url=https://web.archive.org/web/20200727033634/https://www.thepharmaletter.com/article/uk-s-mhra-approves-botox-for-treatment-of-ankle-disability-in-stroke-survivors |url-status=live }}</ref>

In July 2016, the US [[Food and Drug Administration]] (FDA) approved abobotulinumtoxinA (Dysport) for injection for the treatment of lower-limb spasticity in pediatric patients two years of age and older.<ref>{{cite web |title=FDA Approved Drug Products – Dysport |publisher=U.S. [[Food and Drug Administration]] (FDA) |url=https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=125274 |archive-url=https://web.archive.org/web/20161108054053/https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=125274 |archive-date=8 November 2016 |url-status=dead |access-date=7 November 2016}} {{PD-notice}}</ref><ref>{{cite journal |vauthors = Pavone V, Testa G, Restivo DA, Cannavò L, Condorelli G, Portinaro NM, Sessa G |title = Botulinum Toxin Treatment for Limb Spasticity in Childhood Cerebral Palsy |journal = Frontiers in Pharmacology |volume = 7 |pages = 29 |date = 19 February 2016 |pmid = 26924985 |pmc = 4759702 |doi = 10.3389/fphar.2016.00029 |doi-access = free |title-link = doi }}</ref> AbobotulinumtoxinA is the first and only FDA-approved botulinum toxin for the treatment of pediatric lower limb spasticity.<ref>{{cite journal |vauthors = Syed YY |title = AbobotulinumtoxinA: A Review in Pediatric Lower Limb Spasticity |journal = Paediatric Drugs |volume = 19 |issue = 4 |pages = 367–373 |date = August 2017 |pmid = 28623614 |doi = 10.1007/s40272-017-0242-4 |s2cid = 24857218 }}</ref> In the US, the [[prescription drug#Regulation in the United States|FDA approves]] the text of the labels of prescription medicines and for which medical conditions the drug manufacturer may sell the drug. However, prescribers may freely prescribe them for any condition they wish, also known as [[off-label use]].<ref>{{cite journal |vauthors = Wittich CM, Burkle CM, Lanier WL |title = Ten common questions (and their answers) about off-label drug use |journal = Mayo Clinic Proceedings |volume = 87 |issue = 10 |pages = 982–990 |date = October 2012 |pmid = 22877654 |pmc = 3538391 |doi = 10.1016/j.mayocp.2012.04.017 }}</ref> Botulinum toxins have been used off-label for several pediatric conditions, including [[infantile esotropia]].<ref name="Ocampo_2012" />