Sjogren syndrome Quiz: Ace Your Exams

A 59-year-old woman comes to the physician complaining of a “gritty” sensation in the eyes for the last several months. Her eyes have also been itchy and red. In addition, she has trouble swallowing, and food tends to “clump together” in her mouth. Past medical history is significant for allergic conjunctivitis and rhinitis, but these current symptoms are not relieved by oral antihistamines. Temperature is 37.7°C (99.9°F), pulse is 78/min, and blood pressure is 115/72 mmHg. Physical examination reveals conjunctival injection. Further ophthalmologic examination reveals a visual acuity of 20/50 in both eyes. Oropharyngeal examination reveals mucosal atrophy, fissuring of the tongue, and multiple dental caries. No parotid gland swelling is noted. Laboratory testing reveals the following:  

Laboratory value	Result	Reference Range
Hemoglobin	12.3 g/dL	12-16 g/dL
Hematocrit	37%	36-46%
Leukocyte count	9,100/mm3	4,500-11,000/mm3
Platelet count	375,000/mm3	150,000-400,000/mm3
Erythrocyte sedimentation rate	52 mm/h	0-20 mm/h
Antinuclear antibodies	Positive	Negative
Rheumatoid factor	Negative	Negative
Anti-dsDNA	Negative	Negative
Anti-Ro/La	Positive	Negative

The patient is prescribed Cevimeline for management. This medication works via which of the following mechanisms of action?