Monoamine oxidase inhibitors (MAOIs) primarily increase which two neurotransmitters?

Monoamine oxidase inhibitors (MAOIs) are a class of medications used primarily in the treatment of depression. They work by inhibiting the activity of the monoamine oxidase enzyme, which is responsible for the breakdown of monoamines—specifically neurotransmitters such as serotonin, norepinephrine, and dopamine—in the brain.

The correct pairing associated with MAOIs is epinephrine and norepinephrine. By inhibiting monoamine oxidase, MAOIs increase the levels of these neurotransmitters, leading to enhanced signaling in the brain that can help alleviate depressive symptoms. Increased levels of norepinephrine can improve mood and energy, while epinephrine contributes to the overall excitatory response.

While dopamine and serotonin do also play roles in mood regulation and are affected to some extent by MAOIs, the most direct and significant action of MAOIs is seen with epinephrine and norepinephrine. This is important to note as it highlights the mechanism through which MAOIs exert their clinical effects, particularly for patients experiencing depression characterized by low norepinephrine levels.