Editing Botulinum toxin (section)

==Side effects==
While botulinum toxin is generally considered safe in a clinical setting, serious side effects from its use can occur. Most commonly, botulinum toxin can be injected into the wrong muscle group or with time spread from the injection site, causing temporary paralysis of unintended muscles.<ref name="pmid20418969"/> In at least three cases temporary [[diplopia]] was reported due to subcutenious injections for cosmetic purposes.<ref>{{cite journal |vauthors = Sheen-Ophir S, Almog Y |title = [Diplopia following subcutaneous injections of botulinum toxin for cosmetic or medical use] |journal = Harefuah |volume = 152 |issue = 2 |pages = 98–100, 123, 122 |date = February 2013 |pmid = 23513501 |url = https://pubmed.ncbi.nlm.nih.gov/23513501 }}</ref>

Side effects from cosmetic use generally result from unintended paralysis of facial muscles. These include partial facial paralysis, muscle weakness, and [[dysphagia|trouble swallowing]]. Side effects are not limited to direct paralysis, however, and can also include headaches, flu-like symptoms, and allergic reactions.<ref name="Coté_2005"/> Just as cosmetic treatments only last a number of months, paralysis side effects can have the same durations.<ref>{{cite journal |vauthors = Witmanowski H, Błochowiak K |title = The whole truth about botulinum toxin - a review |journal = Postepy Dermatologii I Alergologii |volume = 37 |issue = 6 |pages = 853–861 |date = December 2020 |pmid = 33603602 |doi = 10.5114/ada.2019.82795 |pmc = 7874868 }}</ref> At least in some cases, these effects are reported to dissipate in the weeks after treatment.<ref>{{cite journal |vauthors = Witmanowski H, Błochowiak K |title = The whole truth about botulinum toxin - a review |journal = Postepy Dermatologii I Alergologii |volume = 37 |issue = 6 |pages = 853–861 |date = December 2020 |pmid = 33603602 |pmc = 7874868 |doi = 10.5114/ada.2019.82795 }}</ref> Bruising at the site of injection is not a side effect of the toxin, but rather of the mode of administration, and is reported as preventable if the clinician applies pressure to the injection site; when it occurs, it is reported in specific cases to last 7–11 days.<ref>{{cite journal |vauthors = Hamman MS, Goldman MP |title = Minimizing bruising following fillers and other cosmetic injectables |journal = The Journal of Clinical and Aesthetic Dermatology |volume = 6 |issue = 8 |pages = 16–18 |date = August 2013 |pmid = 24003345 |pmc = 3760599 }}</ref> When injecting the masseter muscle of the jaw, loss of muscle function can result in a loss or reduction of power to chew solid foods.<ref name="Coté_2005" /> With continued high doses, the muscles can atrophy or lose strength; research has shown that those muscles rebuild after a break from Botox.<ref>{{cite news |vauthors = Schiffer J |date=8 April 2021 |title=How Barely-There Botox Became the Norm |work=The New York Times |url=https://www.nytimes.com/2021/04/08/style/self-care-how-barely-there-botox-became-the-norm.html |archive-url=https://ghostarchive.org/archive/20211228/https://www.nytimes.com/2021/04/08/style/self-care-how-barely-there-botox-became-the-norm.html |archive-date=28 December 2021 |url-access=limited |access-date=23 November 2021 |issn=0362-4331 |url-status=live}}</ref>

Side effects from therapeutic use can be much more varied depending on the location of injection and the dose of toxin injected. In general, side effects from therapeutic use can be more serious than those that arise during cosmetic use. These can arise from paralysis of critical muscle groups and can include [[heart arrhythmia|arrhythmia]], [[myocardial infarction|heart attack]], and in some cases, seizures, respiratory arrest, and death.<ref name="Coté_2005" /> Additionally, side effects common in cosmetic use are also common in therapeutic use, including trouble swallowing, muscle weakness, allergic reactions, and flu-like syndromes.<ref name="Coté_2005">{{cite journal |vauthors = Coté TR, Mohan AK, Polder JA, Walton MK, Braun MM |title = Botulinum toxin type A injections: adverse events reported to the US Food and Drug Administration in therapeutic and cosmetic cases |journal = Journal of the American Academy of Dermatology |volume = 53 |issue = 3 |pages = 407–415 |date = September 2005 |pmid = 16112345 |doi = 10.1016/j.jaad.2005.06.011 |url = https://zenodo.org/record/1259075 |access-date = 29 December 2021 |archive-date = 23 May 2022 |archive-url = https://web.archive.org/web/20220523173847/https://zenodo.org/record/1259075 |url-status = live }}</ref>

In response to the occurrence of these side effects, in 2008, the FDA notified the public of the potential dangers of the botulinum toxin as a therapeutic. Namely, the toxin can spread to areas distant from the site of injection and paralyze unintended muscle groups, especially when used for treating muscle spasticity in children treated for cerebral palsy.<ref name=FDA08>{{cite web |url=https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2008/ucm116857.htm |title=FDA Notifies Public of Adverse Reactions Linked to Botox Use |publisher=U.S. [[Food and Drug Administration]] (FDA) |access-date=6 May 2012 |date=8 February 2008 |archive-url=https://web.archive.org/web/20120302084857/https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2008/ucm116857.htm |archive-date=2 March 2012 |url-status=dead}} {{PD-notice}}</ref> In 2009, the FDA announced that boxed warnings would be added to available botulinum toxin products, warning of their ability to spread from the injection site.<ref name=FDA09/><ref>{{cite press release |title=FDA Gives Update on Botulinum Toxin Safety Warnings; Established Names of Drugs Changed |publisher=U.S. [[Food and Drug Administration]] (FDA) |date=3 August 2009 |url=http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2009/ucm175013.htm |archive-url=https://web.archive.org/web/20150924140939/http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2009/ucm175013.htm |archive-date=24 September 2015 |url-status=dead |access-date=18 December 2022}}</ref><ref>{{cite web |title=Update of Safety Review of OnabotulinumtoxinA (marketed as Botox/Botox Cosmetic), AbobotulinumtoxinA (marketed as Dysport) and RimabotulinumtoxinB (marketed as Myobloc) |publisher=U.S. [[Food and Drug Administration]] (FDA) |date=3 August 2009 |url=http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/DrugSafetyInformationforHeathcareProfessionals/ucm174959.htm |archive-url=https://web.archive.org/web/20150701032216/http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/DrugSafetyInformationforHeathcareProfessionals/ucm174959.htm |archive-date=1 July 2015 |url-status=dead |access-date=18 December 2022}}</ref><ref>{{cite web |title=Follow-up to the February 8, 2008, Early Communication about an Ongoing Safety Review of Botox and Botox Cosmetic (Botulinum toxin Type A) and Myobloc (Botulinum toxin Type B) |publisher=U.S. [[Food and Drug Administration]] (FDA) |date=8 February 2008 |url=http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/DrugSafetyInformationforHeathcareProfessionals/ucm143819.htm |archive-url=https://web.archive.org/web/20150602084706/http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/DrugSafetyInformationforHeathcareProfessionals/ucm143819.htm |archive-date=2 June 2015 |url-status=dead |access-date=18 December 2022}}</ref> However, the clinical use of botulinum toxin A in children with cerebral palsy has been proven to be safe with minimal side effects.<ref name=Farag2020/><ref name=Blumetti2019/> Additionally, the FDA announced name changes to several botulinum toxin products, to emphasize that the products are not interchangeable and require different doses for proper use. Botox and Botox Cosmetic were given the generic name of onabotulinumtoxinA, Myobloc as rimabotulinumtoxinB, and Dysport retained its generic name of abobotulinumtoxinA.<ref name="FDA Botulinum" /><ref name="FDA09">{{cite web |url=https://www.pharmaceuticalonline.com/doc/fda-gives-update-on-botulinum-toxin-safety-0001 |title=FDA Gives Update on Botulinum Toxin Safety Warnings; Established Names of Drugs Changed |date=4 August 2009 |website=Pharmaceutical Online |access-date=16 July 2019 |archive-date=6 July 2019 |archive-url=https://web.archive.org/web/20190706132201/https://www.pharmaceuticalonline.com/doc/fda-gives-update-on-botulinum-toxin-safety-0001 |url-status=live }}</ref> In conjunction with this, the FDA issued a communication to health care professionals reiterating the new drug names and the approved uses for each.<ref name=FDA09hc/> A similar warning was issued by [[Health Canada]] in 2009, warning that botulinum toxin products can spread to other parts of the body.<ref>{{cite news |url=https://www.cbc.ca/news/science/botox-chemical-may-spread-health-canada-confirms-1.786237 |work=CBC News |title=Botox chemical may spread, Health Canada confirms |date=13 January 2009 |url-status=live |archive-url=https://web.archive.org/web/20090221144310/http://www.cbc.ca/consumer/story/2009/01/13/botox.html |archive-date=21 February 2009}}</ref>