Which SSRI has the longest half-life?

Which SSRI has the longest half-life?

• A. Sertraline
• B. Citalopram
• C. Fluoxetine
• D. Paroxetine

Answer: (C)

Half-life is the time it takes for the drug’s concentration in the blood to fall by half. Among commonly used SSRIs, fluoxetine stands out because it is converted into an active metabolite, norfluoxetine, which itself has a very long half-life. This combination means the overall elimination of fluoxetine (including its active metabolite) takes quite a long time, so it stays in the body longer than the others. That long half-life has practical implications: it leads to a slower washout after stopping the medicine and can influence how quickly steady-state levels are reached with ongoing dosing.

Half-life is the time it takes for the drug’s concentration in the blood to fall by half. Among commonly used SSRIs, fluoxetine stands out because it is converted into an active metabolite, norfluoxetine, which itself has a very long half-life. This combination means the overall elimination of fluoxetine (including its active metabolite) takes quite a long time, so it stays in the body longer than the others. That long half-life has practical implications: it leads to a slower washout after stopping the medicine and can influence how quickly steady-state levels are reached with ongoing dosing.