Systemic muscular weakness after botulinum toxin A administration: a review of the literature

Abstract

Objectives In this study we perform a review of the literature on systemic muscle weakness after administration of botulinum toxin A, to describe the factors that predispose patients to this adverse event and to suggest strategies for prevention. Methods Our search criteria included the terms "Botulinum toxin, Abobotulinum toxin, Dysport ® , Onabotulinum toxin, Botox ® , Incobotulinum toxin and Xeomin ® , muscle weakness, generalized muscle weakness and respiratory distress." Statistical analysis was completed using IBM ® SPSS software. Results We identified 2029 articles and narrowed this to 38 articles referencing 63 specific cases (including two studies form our institution) and 11 case series. Our analysis of 11 case series suggested that systemic muscle weakness is a rare event with botulinum toxin A. Of the 63 cases identified, the most common indications for use were spasticity (49.2%) and neurogenic detrusor overactivity (22.2%). The median age was low at 34 years, and the majority were female (76.2%). Furthermore, 47.6% of the cases were associated with the abobotulinum toxin A formulation. On average, the doses administered were 3.2 times the recommended dose (standard deviation 1.9) suggested for the particular botulinum toxin A formulation and indication. If systemic muscle weakness did occur, indication for botulinum toxin A being upper tract gastrointestinal disorder was associated with more severe impairment (W 2 = 10.2, p = 0.001). Conclusion Based on data from the identified cases of systemic muscle weakness with botulinum toxin A, this adverse event was more common in female, younger, patients with spasticity or neurogenic detrusor overactivity indication or those receiving abobotulinum toxin A formulation and/or higher botulinum toxin A doses. A prevention strategy may include reducing the dose of botulinum toxin A to those recommended by the US FDA.

Nonsurgical Management of Chronic Exertional Compartment Syndrome with Botulinum Toxin-A

“…Most authors agree that botulism toxicity generally results from the use of an unlicensed botulinum toxin product, or an overdose [25,30]. A systematic review of 63 cases of the systemic muscle weakness related to botulism found that, on average, the doses in affected patients were over three times the recommended dose for the preparation being used [31]. The same review suggested the most practical solution for reducing the risk of botulism is to use botulinum toxin-A preparations that are approved by the United States Food and Drug Administration (FDA) at recommended doses [31].…”

“…A systematic review of 63 cases of the systemic muscle weakness related to botulism found that, on average, the doses in affected patients were over three times the recommended dose for the preparation being used [31]. The same review suggested the most practical solution for reducing the risk of botulism is to use botulinum toxin-A preparations that are approved by the United States Food and Drug Administration (FDA) at recommended doses [31]. Regarding localized decreases in muscle strength, authors noted that these decreases did not result in functional impairment and patients were overall satisfied with the outcomes of their treatments [2,3,12].…”

“…As previously mentioned, appropriate dosing in accordance with FDA recommendations is crucial for reducing the risk of adverse effects of botulinum toxin-A injection [31]. The protocol from the Uniformed Services University of the Health Sciences recommends delivering 25 units of onabotulinum toxin A into proximal and distal locations in each compartment for a total of 50 units per compartment [15].…”