Which of the following is not a tricyclic antidepressant?

Which of the following is not a tricyclic antidepressant?

• A. Amitriptyline (Elavil)
• B. Doxepine (Silenor)
• C. Nortriptyline (Pamelor)
• D. Fluoxetine (Prozac)

Answer: (D)

Fluoxetine is not a tricyclic antidepressant. Tricyclic antidepressants are named for their three-ring chemical structure and typically work by broadly blocking the reuptake of norepinephrine and serotonin, which can lead to a range of anticholinergic and other side effects. Classic examples include amitriptyline, doxepin, and nortriptyline, all of which are TCAs. Fluoxetine, in contrast, is an SSRI (selective serotonin reuptake inhibitor). It specifically and primarily inhibits the serotonin transporter, increasing serotonin in the synaptic cleft, and it does not have the characteristic three-ring structure. This gives it a different mechanism and a different side-effect profile than TCAs. So the one not fitting the tricyclic class is fluoxetine. Amitriptyline, doxepin, and nortriptyline are TCAs.

Fluoxetine is not a tricyclic antidepressant. Tricyclic antidepressants are named for their three-ring chemical structure and typically work by broadly blocking the reuptake of norepinephrine and serotonin, which can lead to a range of anticholinergic and other side effects. Classic examples include amitriptyline, doxepin, and nortriptyline, all of which are TCAs.

Fluoxetine, in contrast, is an SSRI (selective serotonin reuptake inhibitor). It specifically and primarily inhibits the serotonin transporter, increasing serotonin in the synaptic cleft, and it does not have the characteristic three-ring structure. This gives it a different mechanism and a different side-effect profile than TCAs.

So the one not fitting the tricyclic class is fluoxetine. Amitriptyline, doxepin, and nortriptyline are TCAs.