A multicenter maintenance study of oral pilocarpine tablets for radiation-induced xerostomia

Two hundred sixty-five patients with head and neck cancer who had previously participated in either a fixed-dose, dose-titration, or dose-ranging trial of oral pilocarpine hydrochloride tablets were enrolled in a 36-month multicenter maintenance study to evaluate the long-term safety and efficacy of oral pilocarpine for the treatment of radiation-induced xerostomia. In this open-label study, the initial drug dose was 5.0 mg tid, with possible adjustments from 2.5 to 10.0 mg tid or bid. Efficacy was evaluated by subjective measures of oral function. Safety evaluations were based on self-report of symptoms (or of adverse effects), various examinations, and laboratory tests. There was significant improvement in all criteria of oral function. Sweating was the most frequent adverse experience (55%). Less frequent side effects, mild to moderate in nature, included increased urinary frequency, lacrimation, and rhinitis. Side effects usually diminished within hours after the cessation of therapy. We conclude that oral pilocarpine at these doses effectively and safely reduces the symptoms of radiation-induced xerostomia.