Objective: We evaluate the long-term efficacy and safety of incobotulinumtoxinA injections in advanced Parkinson’s disease (PD) patients suffering from sialorrhea.

Background: Sialorrhea is frequently a bothersome problem in patients with advanced Parkinson’s disease.

Method: Patients with idiopathic Parkinson’s disease suffering from sialorrhea were injected with a total of up to 100 U incobotulinumtoxinA (3:2 ratio parotid vs. submandibular gland bilaterally) based on anatomical landmarks every 3 months, unless prolonged effect allowed for a longer interinjection interval.

Efficacy was determined using the 7-point Likert Global Impression of Change Scale (GICS) 6 weeks after each injection, and the Drooling Severity and Frequency Scale (DSFS) at baseline and 6 weeks after every injection.

We actively explored and recorded (if any) the treatment-related adverse events.

Results: Six years into the study now we have included 35 advanced PD patients (average age of 77.7 +/- 2.5 years). 61% had already received botulinum toxin injections for sialorrhea before.

GICS consistently scored improvement (value below 4 (=no improvement) on a 7-point Likert scale) with a mean score of 2.9+/-0.2 at 6 weeks after injection 1 and 2.9+/-0.3 at 6 weeks after injection 7.

The total DSFS decreased from 7.5+/-0.2 at baseline to 5.9+/-0.3 at 6 weeks after the second injection and 5.6+/-0.5 at 6 weeks after injection 7.

Six patients (17,1%) showed efficacy up to 6 months and eight patients (22,9%) stopped injections after 2 to 7 cycles because of a sustained benefit and minimal residual sialorrhea. 

Dry mouth, swallowing difficulties and taste disturbances were the only treatment-related adverse events observed. Overall in 32/213 treatment cycles (15.0 % of overall cycles) did side-effects occur. Swallowing difficulties occurred in 18 cycles (8.5%). These side-effects spontaneously resolved. In six patients (17,1%) a dose reduction to 75 U incobotulinum toxin or lower was warranted because of moderate swallowing difficulties. Treatment interruption was never warranted.

Conclusion: Our interim results confirm the efficacy and safety of repeated incobotulinumtoxinA injections for sialorrhea in PD patients in a real-world setting. 

An increased duration of effect (up to 6 months or longer) is being observed in 14 patients (40,0%).

We recommend starting with 75 U incobotulinum toxin in patients with pre-existing swallowing difficulties.

References: SIAXI Wolfgang H. Jost, Andrzej Friedman, Olaf Michel, Christian Oehlwein, Jaroslaw Slawek, Andrzej Bogucki,Stanislaw Ochudlo, Marta Banach, Fernando Pagan, Birgit Flatau-Baqué, János Csikós, Claire J. Cairney, Andrew Blitzer
Neurology Apr 2019, 92 (17) e1982-e1991; DOI: 10.1212/WNL.0000000000007368

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MDS Abstracts - https://www.mdsabstracts.org/abstract/incobotulinumtoxina-to-treat-sialorrhea-in-parkinsons-disease-a-real-life-study-6-year-interim-results/