Sialorrhea (
drooling) is a common symptom of
Parkinson's disease (PD) that can significantly impair a patient's health and quality of life. Fifty-four PD subjects with troublesome
sialorrhea were enrolled using a multicenter, randomized, double-blind, sequential-dose escalation design in which subjects received a single intraglandular treatment with
botulinum toxin type B (doses of 1,500 Units [0.3 mL]; 2,500 Units [0.5 ml]; or 3,500 Units [0.7 ml]) or placebo. Postinjection, subjects were followed acutely for 4 weeks and long-term for up to 20 weeks. Safety/tolerability, as assessed by adverse events, was the primary outcome measure. Efficacy, as assessed by the
Drooling Frequency and Severity Scale and unstimulated salivary flow rate, was secondary. Gastrointestinal-related adverse events occurred more frequently in the active groups versus placebo group (31% vs 7%), with dry mouth being most common (15%). There were no serious adverse events attributed to
botulinum toxin type B or discontinuations due to adverse events from treatment. At 4 weeks postinjection,
Drooling Frequency and Severity Scale scores significantly improved versus placebo (-1.3 ± 1.3) in a dose-related manner (-2.1 ± 1.2, P = 0.0191; -3.3 ± 1.4, P < 0.0001; -3.5 ± 1.1, P < 0.0001, respectively) and unstimulated salivary flow rates significantly decreased in all active groups versus placebo (P ≤ 0.0009). Furthermore, treated subjects appeared to have more sustained improvement in
sialorrhea than placebo subjects. We conclude that intraglandular injection of
botulinum toxin type B was safe, tolerable, and efficacious in treating
sialorrhea in PD patients. Additional studies are warranted to further confirm the
drug's robust efficacy, as well as evaluate its effect with repeated dosing.