Which of the following medications is MOST likely to contribute to the development of root surface caries?

Correct answer: C. Fluoxetine

• A. Rosuvastatin is a lipid-lowering agent (HMG-CoA reductase inhibitor). Myalgia and hepatic enzyme elevation are its adverse effects; it does not cause xerostomia.
• B. Verapamil is a non-dihydropyridine calcium channel blocker. Its notable oral adverse effect is GINGIVAL HYPERPLASIA, not root caries.
• C. CORRECT. FLUOXETINE is an SSRI antidepressant, and xerostomia is among its most common adverse effects. Reduced salivary flow removes buffering capacity, clearance and remineralizing calcium and phosphate — and in an older adult with gingival recession, the exposed root surface (critical pH ≈ 6.2, versus ≈ 5.5 for enamel) demineralizes first. Antidepressants are one of the most frequently implicated xerostomic drug classes.
• D. Acetaminophen is an analgesic/antipyretic with no salivary effect. Its major toxicity is hepatic.

Note: The big xerostomic classes to know: anticholinergics, antidepressants (SSRIs, TCAs), antihistamines, antipsychotics, diuretics, antihypertensives and opioids. Root caries needs salivary dysfunction PLUS recession.