Which antidepressant class is known to have a risk of serotonin syndrome when combined with certain other medications?

The correct answer is that serotonin-norepinephrine reuptake inhibitors (SNRIs) are known to carry a risk of serotonin syndrome, especially when combined with other medications that also influence serotonin levels. This risk arises because SNRIs increase the availability of serotonin and norepinephrine in the synaptic cleft by inhibiting their reuptake into the presynaptic cell. When SNRIs are taken with other serotonergic agents, such as certain antidepressants, mood stabilizers, or even certain supplements like St. John's wort, the cumulative effect on serotonin can lead to a potentially life-threatening condition known as serotonin syndrome, characterized by symptoms like confusion, agitation, fever, and muscle rigidity.

While selective serotonin reuptake inhibitors (SSRIs) also have a risk of serotonin syndrome due to their mechanism of action focused solely on serotonin reuptake inhibition, the question asks specifically about SNRIs, which adds an additional layer of complexity with their dual action on serotonin and norepinephrine. This dimension heightens the risk when combined with multi-faceted pharmacological agents.

Tricyclic antidepressants (TCAs) and atypical antidepressants do not share the same level of risk for serotonin syndrome as SNRIs, primarily due to