Which among the following selective serotonin reuptake inhibitors is longest acting?

Special points Fluoxetine: It is a prototype SSRI and is longest acting drug in this group. It is metabolized to nor-fluoxetine that retains the anti-depressant activity. Thus it has minimum risk of causing drug-discontinuation symptoms which is characterized by symptoms like paresthesias, body ache & bowel disturbances. Fluvoxamine is the shoest acting SSRI. Paroxetine, seraline and citalopram are other SSRIs. Escitalopram is most specific SSRI. Paroxetine is most teratogenic among SSRIs.