High-dose Botulinum Toxin Therapy: Safety, Benefit, and Endurance of Efficacy.

BACKGROUND

Botulinum neurotoxin therapy (BoNT) is a powerful tool for treating many neurologic disorders. The U.S. Food and Drug Administration (FDA)-approved maximum onabotulinum toxin A (OnaA) dose is 400 units (U) per visit, but higher doses are commonly necessary, particularly when treating multiple body regions.

METHODS

We collected demographics, OnaA dose, body regions injected and indications, patient-reported efficacy via 7-point Clinical Global Impression Scale (CGIS), and duration of benefit.

RESULTS

Sixty-eight patients were identified receiving OnaA >400 U/session. Dystonia (n = 44) and spasticity (n = 24) were the most common indications for high-dose OnaA. Mean duration of benefit was 9 weeks (standard deviation [SD] 3). More than 70% of patients self-reported "very much improved" or "much improved" at 6 month, 1 year, and last visit. No serious adverse effects were reported.

DISCUSSION: The majority of patients tolerated >400 U OnaA with continued benefit. OnaA doses >400 U may be safe and effective in appropriate patients.