title: Adverse Clinical Effects of Botulinum Toxin Intramuscular Injections for Spasticity.
abstract: OBJECTIVE
  The adverse events (AEs) with botulinum toxin type-A (BoNTA), used for indications other than spasticity, are widely reported in the literature. However, the site, dose, and frequency of injections are different for spasticity when compared to the treatment for other conditions and hence the AEs may be different as well. The objective of this study was to summarize the AEs reported in Canada and systematically review the AEs with intramuscular botulinum toxin injections to treat focal spasticity.
  
  
  METHODS
  Data were gathered from Health Canada (2009-2013) and major electronic databases.
  
  
  RESULTS
  In a 4 year period, 285 AEs were reported. OnabotulinumtoxinA (n=272 events): 68% females, 53% serious, 18% hospitalization, and 8% fatalities. The type of AEs reported were - muscle weakness (19%), oropharyngeal (14%), respiratory (14%), eye related (8%), bowel/bladder related (8%), and infection (5%). IncobotulinumtoxinA (n=13): 38% females, 62% serious, and 54% hospitalization. The type of AEs reported were - muscle weakness (15%), oropharyngeal (15%), respiratory (38%), eye related (23%), bowel/bladder related (15%), and infection (15%). Commonly reported AEs in the literature were muscle weakness, pain, oropharyngeal, bowel/bladder, blood circulation, neurological, gait, and respiratory problems.
  
  
  CONCLUSIONS
  While BoNTA is useful in managing spasticity, future studies need to investigate the factors that can minimize AEs. A better understanding of the underlying mechanisms of the AEs can also improve guidelines for BoNTA administration and enhance outcomes.
authors.affiliation: 1Spasticity Research Program,West Park Healthcare Centre,University of Toronto,Toronto,Ontario,Canada.
authors.forename: Chetan P
authors.identifier: http://orcid.org/0000-0003-0957-7941
authors.initials: CP
authors.lastname: Phadke
authors.affiliation: 4Clinical & Applied Movement Sciences,Brooks College of Health,University of North Florida,Florida,USA.
authors.forename: Chitra K
authors.initials: CK
authors.lastname: Balasubramanian
authors.affiliation: 1Spasticity Research Program,West Park Healthcare Centre,University of Toronto,Toronto,Ontario,Canada.
authors.forename: Alanna
authors.initials: A
authors.lastname: Holz
authors.affiliation: 1Spasticity Research Program,West Park Healthcare Centre,University of Toronto,Toronto,Ontario,Canada.
authors.forename: Caitlin
authors.initials: C
authors.lastname: Davidson
authors.affiliation: 1Spasticity Research Program,West Park Healthcare Centre,University of Toronto,Toronto,Ontario,Canada.
authors.forename: Farooq
authors.initials: F
authors.lastname: Ismail
authors.affiliation: 1Spasticity Research Program,West Park Healthcare Centre,University of Toronto,Toronto,Ontario,Canada.
authors.forename: Chris
authors.initials: C
authors.lastname: Boulias
mesh_terms: D019274:Botulinum Toxins, Type A / Q000009:adverse effects*; D002170:Canada; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D009128:Muscle Spasticity / Q000188:drug therapy*; D009465:Neuromuscular Agents / Q000009:adverse effects*; D012189:Retrospective Studies
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A; C545476:incobotulinumtoxinA
keywords: adverse effects; botulinum toxin; dysphagia; muscle weakness; pain; spasticity; systematic review