Use of pilocarpine during head and neck radiation therapy to reduce xerostomia and salivary dysfunction.

Background. Salivary gland hypofunction commonly develops during radiation therapy to the head and neck region. This study evaluated whether the sialogogue pilocarpine given during radiation therapy may reduce the severity of xerostomia and salivary dysfunction. Methods. Nine patients requiring head, neck, or mantle radiation therapy participated in this double-blind, placebo-controlled trial. The patients took either 5 mg of pilocarpine or placebo four times daily for 3 months, beginning the day before radiation therapy. Subjective complaints and salivary functions were assessed. Results. The pilocarpine-treated group had a lower frequency of oral symptoms during treatment than the placebo-treated group. Although salivary flow decreased in all patients, the pilocarpine-treated group had smaller reductions in flow. No drug effect was observed in glands that were irradiated completely. Thus, pilocarpine appeared to stimulate salivary tissues outside the radiation field. Conclusions. These results suggest that stimulation with pilocarpine may reduce the severity of salivary dysfunction and associated oral symptoms during radiation therapy.