Botulinum toxin for the treatment of sialorrhea: a meta-analysis

Botulinum toxin has emerged as an effective approach for the management of sialorrhea. This study presents a critical literature review and meta-analysis to determine the impact of botulinum toxin on drooling severity in patients with sialorrhea.

Ovid MEDLINE and the Cochrane databases.

The above sources were searched to identify studies examining botulinum toxin for the treatment of sialorrhea. Included studies were randomized, placebo-controlled trials. Excluded studies failed to report quantifiable outcome measures of drooling severity at 4 weeks postintervention.

Eight studies involving 181 patients (83 placebo; 98 active) were included in the analysis. Botulinum toxin was found to significantly decrease the severity of drooling in patients with sialorrhea (standardized mean difference [SMD], -1.54; 95% confidence interval [CI], -2.05 to -1.04; P = .06; I (2) = 48%) when compared with placebo control using random effects models. The effect was significant in both adult (SMD, -1.29; 95% CI, -1.88 to -0.71) and pediatric (SMD, -1.84; 95% CI, -2.67 to -1.00) populations. Both botulinum toxin A (SMD, -1.53; 95% CI, -2.27 to -0.79) and B (SMD, -1.56; 95% CI, -2.32 to -0.79) produced similar effects. Botulinum toxin doses greater than 50 U (SMD, -3.81; 95% CI, -6.19 to -1.43) produced much stronger effects compared with doses less than or equal to 50 U (SMD, -1.32; 95% CI, -2.28 to -0.36).

Botulinum toxin is a clinically effective therapy that improves drooling severity in patients with sialorrhea. Future studies will need to further evaluate the technique and examine dosages required to achieve optimal outcomes.