Safety of high-dose botulinum toxin type a therapy for the treatment of pediatric spasticity

This retrospective chart review examines the safety of high-dose (>= 15 U/kg body weight or >= 800 total units) botulinum toxin type A (BOTOX, Allergan Inc., Irvine, CA) in children and young adults with spasticity. Ninety-four children weighing < 45 kg received a mean total dose of 334.1 U or 19.1 U/kg. Fourteen young adults weighing >= 45 kg received a mean total dose of 927.3 U or 15.2 U/kg. Adverse events were reported by 3 of the 108 patients (2.8%) and included single instances of rash and enuresis. The only serious adverse event consisted of mild, generalized botulism in a 13-year-old patient who received a 23 U/kg dose to the hamstrings and gastrocnernius/soleus bilaterally. No serious adverse events were noted in children weighing <= 45 kg who received botulinum toxin type A doses of 15 to 22 U/kg of body weight or in young adults >= 45 kg who received total doses of 800 to 1200 U in a single injection protocol. High-dose botulinum toxin type A is safe for the treatment of spasticity in children and young adults.