The investigators intended for this study to deliver the "proof-of-concept" that locally administered pilocarpine drops in two doses are effective in a population of elderly (aged ≥ 70 years) with xerostomia at the expense of limited adverse events. To this end, the study aims to quantify the effect size of pilocarpine in two different dosages. In case the investigators observe clinically meaningful changes in xerostomia through measured NRS, a sufficiently-powered RCT will be prepared to compare pilocarpine to placebo.

Inclusion Criteria:

• ≥ 70 years of age
• Clinical diagnosis of chronic dry mouth defined as a Numeric Rating Scale (NRS) score ≥ 5 (scale 0 - 10, with 0 = no dry mouth and 10= worst possible dry mouth) on severity of xerostomia for more than 3 months.

Exclusion Criteria:

• Existence of cognitive impairment and/or diagnosis of dementia appraised by treating physician
• Inability to fill out the questionnaires due to other reasons
• Prior radiation therapy of the head-and-neck region
• Known m. Sjögren disease
• Contra-indications for parasympathicomimetics (uncontrolled asthma, acute heart failure, active peptic ulceration, known hypersensitivity to pilocarpine, and when miosis is undesirable, e.g., in acute iritis and in narrow-angle (angle closure) glaucoma.