Adverse events after chemodenervation with onabotulinum neurotoxin A in children with hypertonia and sialorrhea.

Aim: To identify the incidence and type of adverse events reported after chemodenervation with onabotulinum neurotoxin A (BoNT-A) in children with hypertonia and sialorrhea and compare adverse events in the on-label or off-label use of BoNT-A with regard to dose, patient's age, and location of the injection.

Method: Using a retrospective chart review, we studied BoNT-A injections occurring from January 2017 to December 2020 in patients at a pediatric hospital. The electronic health record was examined to identify adverse events reported within 2 months of the injection. Data included the patient's age, sex, race, and ethnicity, as well as the type of toxin injected, the dose, the location of injection, and the patient's weight.

Results: We analyzed 1733 procedures. Adverse events were infrequent (2.5%) and not serious, most commonly reported as pain or discomfort. All adverse events were temporary and there were no deaths. We did not observe a meaningful difference in the frequency of adverse events for injections that exceeded the 2022 US Food and Drug Administration (FDA)-approved maximum dose compared to injections that were within the FDA-approved dose range. The likelihood of adverse events did not increase with higher doses of BoNT-A. More adverse events were reported for injection into the salivary glands (4.37%) than into the extremities (2.26%).

Interpretation: Higher doses of injected BoNT-A in a pediatric population may be safe. Further work is needed to investigate the relationship between dose and efficacy.