I can say is that Prozac. It does have the longest half-life of the SSRI's. So, the issue he/she might be thinking. Is how you have a reaction to it. Obviously, if it is in the first days. Then it is a quick stop. The issue basically comes down to - you will "probably" feel the side effects within days. The longer you use any med with a long half-life the longer it takes to clear your system. So, I think he/she wants to know how you are feeling for the first week=s.e. Once you are on it for a few weeks It does take a lot longer to clear your system and there is the issue. If it works= gold with a problem is with others people physiological make up. It takes a longer clearing out period!
Some links to use and learn from:
Selecting a Selective Serotonin Reuptake Inhibitor: Clinically Important Distinguishing Features
Clinical Pharmacology of SSRI's: What Are the Clinically Relevant Pharmacokinetic Differences Among SSRIs?
Antidepressants: Comparison of SSRIs
You can find heaps of info. and studies on SSRI's and non-life threatening side effects. Not in a dangerous way usually, except, Serotonin Syndrome .That you doc/pdoc should explain! Not anywhere as dangerous as other meds. Relatively benign for most peoples. That is why it is usually the first line of treatment for depression/anxiety disorders but thats why you need a good doc!!! : )
Always ask about serotonin syndrome. If you are on an SSR because taking a supplement like 5-HTP, L-Tryptophan and some other natural or medical medicines will cause an overload of 5HT in the brain. It's not hard to avoid and usually happens if someone takes certain supplements. A good basic multi is usually great but your doc shoul;d know and if does not tell you. Tell him/her you need to know!