This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: CNS, Subject name: Pharmacology
Which among the following selective serotonin reuptake inhibitors is longest acting? 
Select and explain. 
A. Fluvoxamine, B. Fluoxetine, C. Seraline, D. Paroxetine
B: Fluoxetine
Answer: B: Fluoxetine 
Explanation: 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.