Pharmacology of Selected Therapeutic Agents in Oral Medicine
Xerostomia and Dry Mouth

Xerostomia, the subjective complaint of oral dryness, affects an estimated 17-29% of patients and women are affected more frequently than men.¹ The subjective complaint of oral dryness may or may not be accompanied by an objective decrease in the salivary flow rate, when measured by sialometry. It is generally accepted that unstimulated whole saliva (WS) flow rates of <0.1 mL/min and stimulated WS flow rates of <0.7 mL/min are indicative of marked salivary gland hypofunction.²

Causes of salivary gland dysfunction are numerous and include medications (e.g., antidepressants, antipsychotics, anticholinergics, antihypertensives, antihistamines, and sedatives). Other causes include caffeine and alcohol; cigarette smoking: radiation to the head and neck; systemic diseases (e.g., diabetes mellitus); autoimmune diseases (e.g., Sjögren’s syndrome); salivary gland tumors, malnutrition, and other unspecified or undiagnosed conditions.^2,3

Signs and symptoms of salivary gland dysfunction vary from patient to patient and include: xerostomia, oral dryness, peeling of the lips, difficulty chewing, dysgeusia, dysphagia, and/or dysphonia (Figure 1). Patients with salivary gland dysfunction may develop local and systemic complications such as dental caries, oral pain, mucosal sensitivity, oral ulcers, fungal infections, and halitosis.⁴ An in depth review of saliva is presented elsewhere.⁵