Botulinum Toxin Type A Overdoses: Analysis of the FDA Adverse Event Reporting System Database.

[INTRODUCTION] Published literature on overdoses related to botulinum toxin A (BtxA) agents is scarce.

[OBJECTIVE] The aim of this study was to assess the BtxA drug class' respective agents for associations with overdose.

[METHODS] United States Food and Drug Administration (FDA) adverse event reporting system (FAERS) database was utilized to search for overdoses. The analysis was conducted on data between second quarter 2014 and third quarter 2017. BtxA cases were included when they were considered the "Primary Suspect" drug. Overdose was defined as presence of 'overdose' being reported as an adverse event. Primary outcome was incidence of 'overdose' compared within the respective agents. Additionally, a disproportionality analysis was conducted utilizing reporting odds ratio (ROR) versus onabotulinumtoxinA as a referent while controlling for confounding variables.

[RESULTS] A total of 3,837,406 unique adverse events were reported during the study period for all drugs in the FAERS database. Of which, 13,078 were BtxA cases. The rate of adverse events involving overdose for abobotulinumtoxinA (20.2%; 215/1065) was significantly higher than both onabotulinumtoxinA (0.4%; 48/11,323; p < 0.0001) and incobotulinumtoxinA (0.1%; 1/690; p < 0.0001). In the regression analysis, abobotulinumtoxinA (ROR 73.26; 95% CI 51.17-104.90) had a significant association with overdose, whereas incobotulinumtoxinA (ROR 0.73; 95% CI 0.10-5.36) did not, versus the referent onabotulinumtoxinA.

[CONCLUSION] The present analysis showed adverse events of abobotulinumtoxinA were significantly associated with overdose versus the other two BtxA agents. Overdose can be difficult to research, particularly for in-clinic administered drugs. Future studies should venture to confirm these results in new and novel ways.