Which of the following is a common serotonin-norepinephrine reuptake inhibitor (SNRI)?

Cymbalta, also known as duloxetine, is indeed a common serotonin-norepinephrine reuptake inhibitor (SNRI). SNRIs like duloxetine work by inhibiting the reuptake of both serotonin and norepinephrine in the brain, which helps to increase the levels of these neurotransmitters and can be effective in treating conditions such as major depressive disorder and generalized anxiety disorder.

In contrast, the other medications listed serve different functions and belong to different classes. Elavil (amitriptyline) is a tricyclic antidepressant, which primarily affects serotonin and norepinephrine but does not fit the SNRI classification as its mechanism is broader and not as selective. Nardil (phenelzine) is a monoamine oxidase inhibitor (MAOI), which works by inhibiting the breakdown of neurotransmitters, and Wellbutrin (bupropion) is a dopamine and norepinephrine reuptake inhibitor (NDRI) that primarily affects dopamine and norepinephrine but not serotonin. This highlights why duloxetine is specifically categorized as an SNRI, distinguishing its pharmacological action from the others.