Assessment of the Preventive Effect of Pilocarpine on Radiotherapy-Induced Xerostomia in Patients with Head and Neck Cancers

Introduction: Xerostomia is one of side-effects of radiotherapy for head and neck cancers. No definitive method has been proposed for the treatment of this condition. However, pilocarpine is considered effective for the management of chronic xerostomia. The purpose of the present study was to assess the preventive effect of pilocarpine. Materials and Methods: This study was performed on 34 patients with head and neck cancers, undergoing radiation therapy (5000 cGy). The patients were randomly divided into two groups. The case group was administered 16 drops of pilocarpine (2%) eye drops per day, while the control group received normal saline; the treatment plan continued for four weeks. Unstimulated whole saliva flow rate was measured at four stages: two weeks before radiotherapy (baseline), the first day of radiotherapy, and two and four weeks after the initiation of radiotherapy. Results: At baseline and the first day of radiotherapy, no significant differences were observed in the amount of saliva between the case and control groups (P 0.76 and P 0.054, respectively). However, by starting radiotherapy, a statistically significant improvement was reported in saliva production in the case group, compared to the control group (P 0.00); this trend continued during the next four weeks of radiotherapy (P 0.003). Generally, a significant difference was observed between the two groups at all stages of data evaluation (P 0.00). Conclusion: According to the findings, pilocarpine was found to be effective for the prevention of xerostomia. Moreover, it could restrain the decline in the amount of saliva and reduce the rate of xerostomia.