LAUSR

• There are three FDA (Food and Drug Administration) approved botulinum toxin type A (BoNT-A) agents: onabotulinumtoxinA (Botox; Allergan, Inc.; initial FDA approval 1989), abobotulinumtoxinA (Dysport; Galderma Laboratories, L.P. for cosmetic; initial FDA approval 2009), and incobotulinumtoxinA (Xeomin; /Bocouture, Merz Pharmaceuticals GmbH; initial FDA approval 2010). Specific potency units, dosing, and reconstitution are unique for each botulinum toxin type A agent. Published literature comparing BoNT-A agents for antibody formation, resistance, and loss of effect is lacking. IncobotulinumtoxinA is the only botulinum toxin type A (BoNT-A) agent that has removed the unnecessary proteins, leaving just the 150 kDa active component. • The FDA Adverse Event Reporting System (FAERS) is an open access data-base, which contains passive adverse event surveillance data reported to the FDA by health professionals, consumers, or pharmaceutical manufacturers, and helps to support the FDA’s post-approval safety surveillance program . FAERS is the world’s largest pharmacovigilance database to date, with over 9 million adverse events reported just since 2004. • The aim of this analysis was to assess the BoNT-A agents for decreased therapeutic effect over time.