Pathology · patient case question
Given her medication list, what is the most likely cause of her xerostomia beyond the autoimmune disease itself?
Patient case: The mouth that will not stay wet
demo: 54-year-old female
chief: Burning, sticky mouth for the past eight months; food gets caught and she wakes at night to sip water.
history: Hashimoto thyroiditis. Her rheumatologist ordered an autoantibody panel after she reported gritty, burning eyes.
meds: Levothyroxine 75 mcg daily. Amitriptyline 25 mcg at night for chronic tension headache.
findings: Anti-SSA (Ro) strongly positive. Salivary pooling is absent; the mucosa is dry and the tongue is fissured with papillary atrophy. Cracking and erythema at both commissures. Two new cervical lesions since her last visit a year ago.
Show answer and explanation
Correct answer: B. Amitriptyline
- A. There is no history of head and neck radiation, so this can be excluded from the differential.
- B. Correct. Amitriptyline blocks muscarinic receptors on salivary acinar cells and is a classic pharmacological cause of dry mouth. In a patient with an autoimmune exocrinopathy the drug effect stacks on top of the disease and is the modifiable part.
- C. Levothyroxine replaces thyroid hormone and does not have anticholinergic activity. Xerostomia is not one of its recognised effects.
- D. A salivary stone would give episodic, meal-related swelling and pain in one gland. Nothing in the history describes that, and stones do not cause generalised dryness.