Data sourcesCochrane Oral Health Group Trials Register, Cochrane Central Register of Controlled Trials, Medline, Embase and CINAHL databases. Reference lists of identified articles were checked and experts in the field and relevant pharmaceutical companies were contacted.Study selectionRandomised controlled trials, including parallel and crossover, carried out in any setting on any patient population with radiation-induced salivary dysfunction using parasympathomimetics drugs.Data extraction and synthesisThe two authors independently assessed for inclusion, established the risk of bias and abstracted data. The primary outcome was level of xerostomia. The authors intended to report risk ratio, odds ratio, risk difference and NNT for dichotomous data and mean difference and standard mean difference for continuous data.ResultsOf the three included studies, one (n=20) reported mean improvement on the VAS (22.5 mm on a 100 mm scale). The other two studies considered a change in 25 mm on the VAS a positive response. Of those one (n=207) reported positive response in 51% of subjects on 5mg of pilocapine TID and 47% for 10mg TID. The second (n= 162) reported a 42% positive response with a titrated dose regimen. The side effects rate was high,and the main reason for discontinuation.ConclusionsThere is limited evidence to support the use of pilocarpine hydrochloride in the treatment of radiation-induced xerostomia. Currently, there is little evidence to support the use of other parasympathomimetic drugs in the treatment of radiation-induced xerostomia. Available studies suggest that approximately half of patients will respond, but side effects can be problematic. The conclusions of the update are the same as the conclusions of the original review, since no new relevant studies have been published in the interim.