Concomitant pilocarpine during head and neck irradiation is associated with decreased posttreatment xerostomia

Abstract

Purpose : To retrospectively compare subjective postirradiation xerostomia scores of patients who received concomitant oral pilocarpine during radiotherapy for head and neck cancer and 3 months thereafter with those of similar cohorts who did not receive pilocarpine. Methods and Materials : Subjective serostomia was assessed using a visual analog scale xerostomia questionnaire that measured oral dryness, oral comfort, difficulty with sleep, speech, and eating. The concomitant pilocarpine group had both paratid glands in the initial field treated to at least 45 Gy and received 5 mg pilocarpine hydrochloride four times per day (q.i.d.) beginning on the first day of radiotherapy and continuing for 3 months after completion of radiation. The control cohort had also received at least 45 Gy to both parotid glands and had not received pilocarpine at the time of evaluation. Scores on the visual analog scale were averaged and compared using the Student's t-test. Results : Seventeen patients who received concomitant pilocarpine during head and neck irradiation and 18 patients who had not been treated with pilocarpine were available for follow-up. The mean intervals between completion of radiation and evaluation of xerostomia were 17 months and 16 months, respectively. Only one of the pilocarpine-treated patients was still taking pilocarpine at the time of evaluation. For each of the individual components of xerostomia scored on the visual analog scale, as well as the composite of all components, the group that had received oral pilocarpine during radiation had significantly less xerostomia ( p < 0.01 for each). Conclusions : The use of 5 mg oral pilocarpine q.i.d. during radiotherapy for head and neck cancer and 3 months thereafter was associated with significantly less subjective xerostomia than that reported by a similar cohort of patients who had not received pilocarpine. The continued use of pilocarpine does not appear to be necessary to maintain this benefit in most patients.