dry mouth

Xerostomia (dry mouth) is a condition commonly encountered in clinical practice that can lead to multiple oral and systemic health problems. This condition has several potential etiologies, including medications, advancing age, head and neck radiation, and systemic diseases. Individuals with xerostomia are at increased risk for dental caries, infections of the oral cavity, generalized oral pain, poor nutrition intake, and significantly reduced quality of life. Topical sialogogues may be of limited benefit for patients with this condition, and systemic medications may be necessary to achieve improved clinical outcomes.

A pilot study by Brimhall and colleagues compared the efficacy of pilocarpine and cevimeline in the secretion of saliva and evaluated side effects of both medications. Pilocarpine is a cholinergic agonist that promotes generalized fluid secretion by acting on systemic muscarinic-cholinergic receptors. Cevimeline, another systemic agent that promotes fluid secretion, has higher affinity for muscarinic receptors located on lachrymal and salivary gland epithelium and is thought to produce fewer side effects than pilocarpine.

Twelve patients with moderate to severe xerostomia were included in the final analysis of this crossover, double-blind, randomized study. One half of the patients were randomly selected to receive cevimeline 30 mg 3 times daily for 4 weeks. This was followed by a 1-week washout period and initiation of therapy with pilocarpine 5 mg 3 times daily for 4 weeks. The other half of the patients were randomly selected to take pilocarpine first, followed by cevimeline in the same way as described previously.

Patients were evaluated by clinicians 3 times throughout the study: at baseline for informed consent, after the first 4 weeks of therapy, and then 5 weeks later (after the 1-week washout period and 4 weeks of the second medication course). Unstimulated and stimulated salivary flow measurements were obtained at each visit using standard techniques. Patients completed a weekly questionnaire about side effects of therapy, and the questionnaires were evaluated at each visit.

The results of the study were as follows:

Most cases of xerostomia (58%) in this cohort were caused by medications;

Although there was an overall increase in production of both unstimulated and stimulated saliva in patients taking either cevimeline and pilocarpine, the medications did not differ statistically in this regard; and

Patient-reported side effects of both medications included increased sweating, watering eyes, headache, nausea, stomach upset, diarrhea, and pain around the eyes; however, there was no statistical difference between the medications in the frequency or severity of side effects.