Which of the following SSRIs is characterized by the longest half-life?

Fluoxetine, commonly known as Prozac, is characterized by the longest half-life among selective serotonin reuptake inhibitors (SSRIs). Its half-life can range from 4 to 16 days, and this extended duration is attributed to its active metabolite, norfluoxetine, which also contributes to its antidepressant effects and can persist in the body for weeks after discontinuation.

This prolonged half-life allows for more flexible dosing and provides a gradual withdrawal process, reducing the risk of withdrawal symptoms compared to other SSRIs that have shorter half-lives. As a result, fluoxetine is often considered in cases where a longer-acting medication is preferred, making it suitable for maintaining therapeutic levels even if a dose is occasionally missed.

In contrast, other SSRIs like sertraline, escitalopram, and paroxetine have shorter half-lives, which can require more frequent dosing and carry a higher potential for withdrawal symptoms if discontinued abruptly. These characteristics differentiate fluoxetine as the option with the longest half-life among the given SSRIs.