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 weremuscle 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. Conclusion: 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.RÉSUMÉ: Réactions indésirables à des injections intramusculaires de toxine botulique utilisée pour traiter la spasticité. Objectif: Les réactions indésirables (RI) à la toxine botulique de type A (BoNTA) utilisée à des fins autres que le traitement de la spasticité ont été abondamment rapportées dans la littérature. Cependant, le point d'injection, la dose et la fréquence des injections sont différents quand elle est utilisée pour traiter la spasticité par rapport à son utilisation pour traiter d'autres affections et donc les RI peuvent également être différentes. Le but de cette étude était de présenter un sommaire des RI rapportées au Canada et de revoir systématiquement les RI rencontrées lors d'injections intramusculaires de toxine botulique pour traiter la spasticité focale. Méthode: Nous avons recueilli les données de Santé Canada de 2009 à 2013 et ainsi que celles des principales bases de données électroniques. Résultats: Au cours d'une période de 4 ans, 285 RI ont été rapportées, dont 272 RI avec l'onabotulinum toxine A. Soixante-huit pour cent sont survenues chez des femmes, 53% étaient des RI sérieuses, 18% ont nécessité une hospitalisation et 8% ont été fatales. Les RI rapportées étaient de la faiblesse musculaire (19%), des RI oropharyngées (14%), respiratoires (14%), oculaires (8%), en lien à l'intestin / la vessie (8%) et infectieuses (5%). Avec l'incobotulinum toxine A (n = 13) les RI rapportées sont survenues chez des femmes dan...

Human recombinant hyaluronidase injections for upper limb muscle stiffness in individuals with cerebral injury: A case series

“…The injections were safe and well tolerated, and without clinically significant adverse effects. Most importantly, the treatment did not produce weakness, which is a common adverse effect with current treatment options for spasticity (Phadke et al, 2015). Side effects of muscle weakness and fatigue are major impediments to recovery in patients with neurologic injury.…”

“…Current treatment options for spasticity include oral medications such as benzodiazepines, baclofen, and tizanidine that are central nervous system depressants used to suppress spinal hyper-excitability, and local injections of botulinum toxin used to suppress muscle overactivity. Whereas the oral medications can produce cognitive deficits, fatigue, and muscle weakness, botulinum toxin injections produce focal muscle weakness (Phadke et al, 2015). It is thus necessary to carefully balance the risks and benefits of treatment, which often remains inadequate.…”

Centrally mediated late motor recovery after botulinum toxin injection: Case reports and a review of current evidence

“…Adverse clinical effects following intramuscular injection of BoNT are well established, with some patients reporting muscle weakness, oropharyngeal/ respiratory alterations, bowel and bladder disturbances and infections, some of which require higher levels of care (31). Instrumented guidance of BoNT injection, such as electrical stimulation or ultrasonography, is strongly recommended (32,33).…”

Safety and Stability of Pulmonary Function in Patients with Decreased Respiratory Function Treated for Spasticity with OnabotulinumtoxinA

“…OnabotA is administered locally and the clinical effects are expected to be limited to structures in the vicinity of the injection region. However, respiratory-related adverse events and respiratory dysfunction have been reported in some patients following injection into the limbs for the treatment of spasticity, although these are not always considered treatment related [ 4 , 5 , 6 ]. These changes may be due to systemic spread of toxin at high doses or from worsening neurologic status from spasticity, cognition, or other unrelated medical illness.…”