Botulinum Toxin a in the Treatment of Sialorrhea

OBJECTIVE: To review the efficacy and safety of botulinum toxin A (BTX) in the treatment of sialorrhea. DATA SOURCES: A PubMed search and reference list review was performed to find clinical trials on BTX in the treatment of sialorrhea. The search was limited to English-language trials involving human subjects. Articles from 1965 to October 2006 were searched, using key words botulinum, botulinum toxin, Botox, sialorrhea, saliva, salivary gland, and drooling. STUDY SELECTION AND DATA EXTRACTION: Reports of 15 studies were found on BTX in the treatment of sialorrhea in human subjects. Four controlled trials are presented in detail, and 11 uncontrolled studies are summarized. DATA SYNTHESIS: One controlled trial found that BTX caused significant reductions in patients' severity and frequency of drooling compared with placebo. Another found significant saliva reductions in the treatment group receiving the highest dose of BTX but found no subjective improvement compared with the placebo group. A third study comparing BTX with placebo found significant improvements in subjective and objective measures of drooling in the treatment group. A fourth controlled trial found significant reductions from baseline levels of drooling after patients received BTX injections. Similar efficacy was found between the BTX and scopolamine treatment groups. CONCLUSIONS: Evidence indicates that BTX is a safe and effective treatment for sialorrhea. More research is needed to determine the ideal dose, injection location, and technique of BTX injections.