Which of the following SSRIs is known for having the longest half-life, allowing for once-daily dosing and potentially less severe discontinuation symptoms if a dose is missed?

Explanation

Fluoxetine has the longest half-life among the commonly used SSRIs, typically ranging from 4 to 6 days for the parent compound and 9 to 10 days for its active metabolite, norfluoxetine. This long half-life allows for once-daily dosing and provides a 'self-tapering' effect, which generally leads to a lower risk and less severe discontinuation symptoms compared to SSRIs with shorter half-lives (e.g., paroxetine, which has a half-life of about 21 hours). Sertraline and citalopram have intermediate half-lives (around 24-30 hours).