Botulinum toxin type A1 is a first-line treatment for adult and pediatric spasticity. However, when considering the quantity of 150 kDa neurotoxin protein in relation to patient weight and the maximum recommended dose for treating adult and pediatric patients with spasticity, several concerns arise. First, the therapeutic margin (the ratio of the actual maximum quantity of toxin recommended for treating adult spasticity to its median lethal dose) appears to be relevant. Second, there is no consistency between adult and pediatric dosing of botulinum toxin type A1 for spasticity. The third point concerns the suitability of the recommended doses for treating spasticity in pediatric patients. Based on the average body weight of American children and adolescents, the maximum weight-based doses for abobotulinumtoxinA and onabotulinumtoxinA could be administered to children as young as 9 years old. Additionally, the maximum weight-based dose for incobotulinumtoxinA could be administered to children as young as 6 years old. The final point concerns managing the maximum dose of BoNT/A1 in pediatric patients with spasticity who weigh more than 25 kg for incobotulinumtoxinA, or more than 34 kg for abobotulinumtoxinA and onabotulinumtoxinA. No labeled recommendations are given on the weight cut-off for transitioning to adult dosing in pediatric patients.
Keywords: botulinum toxins; muscle spasticity; therapeutics.