Effectiveness of the pharmacological treatments for sialorrhea in patients with Parkinson's disease: a systematic review and network meta-analysis.

[OBJECTIVES] The present systematic review and network meta-analysis of randomized control trials (RCTs) aimed to establish whether there are evidence-based differences in the pharmacological agents used to manage sialorrhea in patients with Parkinson's disease (PD).

[MATERIAL AND METHODS] The authors searched the databases: MEDLINE via PubMed, EMBASE, Scopus, Web of Science, and Cochrane Library for clinical trials. Unpublished trials were searched on clinicaltrials.gov and the Brazilian Clinical Trials Registry. Means and standard deviations of changes in the salivary flow or drooling reported by participants due to the interventions were recorded.

[RESULTS] The authors analyzed 13 RCTs. Compared to the placebo, types A and B of the botulinum toxin effectively reduced the salivary flow and the severity or frequency of drooling. However, the network meta-analysis did not differentiate between the botulinum toxin types. Ipratropium bromide and glycopyrrolate did not differ from the placebo. Indirect evidence showed that ipratropium had similar results to those obtained with both types of botulinum toxin. The CINeMA approach estimated the quality of the evidence as very low for all comparisons.

[CONCLUSION] The best treatment for sialorrhea in patients with PD is not fully elucidated yet. Therefore, more well-conducted randomized clinical trials are required to increase the level of evidence.

[CLINICAL RELEVANCE] There needs to be more evidence defining the best intervention to treat sialorrhea in patients with PD. However, botulinum toxin types A and B seem to reduce sialorrhea in patients effectively.