A 78-year-old woman is treated for depression with nortriptyline. Which of the following is the most common side effect of nortriptyline?

Antihistamine side effects (sedation) and anticholinergic side effects (dry mouth, constipation, urinary hesitancy, blurred vision) are the most common side effects. Orthostasis is probably the most common serious side effect and is difficult to manage. Severe cardiac toxicity is uncommon and diarrhea and weight loss are associated with SSRI antidepressants.