OUTLINE: This is a randomized, double-blind, multicenter study. Patients receive either oral pilocarpine four times daily (arm I) or oral placebo four times daily (arm II) for 4 weeks. At the end of the 4 weeks, all patients are given the option to receive oral pilocarpine. Quality of life is assessed 2 days prior to randomization, after 2 weeks of treatment, and after 4 weeks of treatment.