Review Question - QID 106857

This patient presented with priapism following recent initiation of treatment for depression with insomnia. The most likely cause is the atypical antidepressant trazodone.

Trazodone is an atypical antidepressant that commonly causes sedation. Thus, trazodone is frequently used as part of therapy for depression associated with insomnia. A feared (and frequently tested) side effect of trazodone is priapism.

Adams et al. discuss pharmacotherapy in depression, and report common side effects associated with common antidepressants. All antidepressants are associated with side effects. Selection of the appropriate antidepressant for a given patient often involves consideration of the side effects of the particular antidepressant.

Fagiolini et al. explains that trazodone is in the category of serotonin receptor antagonists and reuptake inhibitors. Clinical trials have demonstrated that trazodone has comparable antidepressant effects to other common classes, including SSRIs. The most common side effect of trazodone is drowsiness/somnolence. Because of this side effect, trazodone is useful for patients with depression and insomnia.

Illustration A is a table showing side effects commonly associated with some atypical antidepressants.

Incorrect answers:
Answers 1-2: Bupropion and venlafaxine are also antidepressants, but are not associated with priapism.
Answer 4: Sickle cell disease is associated with priapism, but is unlikely in a Caucasian patient with no history of sickle cell related complications at age 23.
Answer 5: Malaria infection can be associated with priapism, but is unlikely in this patient for two reasons. One, Mexico is not a high-risk malaria region. Two, malaria generally presents soon after exposure, and would be unlikely to present five months after travel.