Which one of the following antidepressants can be used as an antipruritic agent and for the treatment of gastric ulcer because of its potent histamine blockade?

Amitriptyline is an effective choice for use as an antipruritic agent and in the treatment of gastric ulcers due to its potent blockade of histamine receptors. This tricyclic antidepressant not only alleviates depressive symptoms but also possesses antihistaminic properties, which can help relieve itching associated with various dermatological conditions. Furthermore, its ability to block histamine significantly contributes to its effectiveness in reducing gastric acid secretion, thereby providing therapeutic benefits for gastric ulcer management.

While other options like trazodone, fluoxetine, and citalopram are primarily focused on treating depression and may have some minor antihistaminic effects, they do not exhibit the same level of efficacy in terms of alleviating pruritus or treating gastric ulcers as amitriptyline does. Trazodone is often used for insomnia and has some sedative effects, whereas fluoxetine and citalopram are selective serotonin reuptake inhibitors (SSRIs), which are primarily focused on enhancing serotonin levels rather than exerting significant antihistaminic or antiulcer effects. Hence, amitriptyline is uniquely positioned with both antidepressant and additional therapeutic benefits related to histamine blockade.