Reducing the incidence of 131I-induced sialadenitis: the role of pilocarpine.

The goal of this study was to reduce the salivary symptoms of pain and xerostomia caused by 131I therapy for papillary and follicular thyroid carcinoma. In a single-blind controlled prospective study of 60 patients, we investigated whether pilocarpine, 5 mg orally every 8 h for 1 wk after 131I therapy, would reduce salivary symptoms. All patients received 8 mg of dexamethasone and 100 mg of dolasetron mesylate orally 2 h before therapy and every 12 h for another 5 doses after 131I ingestion. In addition, for a week after therapy all drank 2,400 mL of nondairy liquid per day and had sugar-free gum or candy in their mouths at all times when awake for a week and, for the first 3 nights, every 3 h after retiring. All brushed their mouths out every 3 h while awake and also for the first 3 nights after 131I therapy. Symptoms and signs were followed by frequent telephone calls over the first week and every 8-12 wk thereafter, a physical examination within the first 10 d after therapy, and a clinic visit 6-8 mo after therapy. Statistical comparisons were by chi2 analysis. The 2 patient groups were not statistically different in age, sex, type of thyroid cancer, or 131I activity administered (P > 0.05). There were no statistical differences between the groups in the prevalence of sialadenitis, stomatitis, xerostomia, or dysgeusia over the next 6 mo (P > 0.05). Under the conditions of the study, pilocarpine did not reduce the occurrence of radiation sialadenitis or stomatitis. The occurrence, however, was lower than had previously been reported in the literature, possibly because of the concurrent stringent application of physiologic sialogogues (candy, gum, fluids), dexamethasone, and dolasetron mesylate, a serotonin receptor antagonist.