What can occur as a result of increased norepinephrine by MAOIs?

The correct choice regarding what can occur as a result of increased norepinephrine due to the use of monoamine oxidase inhibitors (MAOIs) is hypertensive crisis. MAOIs work by inhibiting the enzyme monoamine oxidase, which is responsible for the breakdown of neurotransmitters including norepinephrine. When norepinephrine levels rise significantly, especially in response to certain dietary amines (like tyramine found in aged cheeses, cured meats, or certain wines), this can lead to an excessive increase in blood pressure.

A hypertensive crisis is characterized by a sudden and severe increase in blood pressure that can lead to serious complications like stroke or heart failure if not managed promptly. People taking MAOIs must be vigilant about their diet to avoid foods that can trigger this reaction.

The other results listed, such as dry mouth, sedation, and insomnia, can occur but are typically not directly attributable to the increased norepinephrine levels specifically associated with MAOI usage. Instead, those effects may be linked to the overall pharmacological profile of other classes of antidepressants or different mechanisms altogether.