A patient takes bupropion. Which side effect is of MOST direct relevance to dental care?

Correct answer: C. Xerostomia

• A. Bupropion TREATS depression — it is an atypical antidepressant inhibiting norepinephrine and dopamine reuptake, and is also marketed as Zyban for smoking cessation. Depression is the indication, not the side effect.
• B. Bupropion is associated with TACHYCARDIA and hypertension rather than bradycardia, reflecting its noradrenergic action.
• C. CORRECT. XEROSTOMIA is among the most frequently reported adverse effects of bupropion and is the one that matters chairside: reduced salivary flow raises caries risk (particularly cervical and root caries), predisposes to candidiasis, and makes denture wear uncomfortable. Manage with topical fluoride, salivary substitutes, frequent sips of water, sugar-free xylitol gum and shortened recall intervals.
• D. Gingival hyperplasia is caused by phenytoin, cyclosporine and the dihydropyridine calcium channel blockers such as nifedipine — not by bupropion.

Note: Bupropion's other clinically important property is that it LOWERS THE SEIZURE THRESHOLD — it is contraindicated in patients with a seizure disorder, bulimia or anorexia. It is also the antidepressant least associated with sexual dysfunction, which is why it is often selected.