I think serotonin syndrome would be very unlikely to occur.

Here's one possible rationale. See what you think of it.

After the animal studies showing that SSRI antidepressants had a protective effect on neurons exposed to MDMA, people who were worried about the potential toxicity of MDMA began to combine the two drugs. At this point, who would be most likely to be screaming out that this wasn't safe,if it really wasn't safe? I'd say it would be those people who thought enough of it to combine the drugs in the first place. The fact that we have not had headline bulletins that the combination is unsafe leads me to believe that it is safe. We'd have heard otherwise.

All comments preceding assume a definition of safe as "safe in the context of using street drugs".

As to Prozac's half-life, the literature has it at up to 6 days after chronic exposure, and the active metabolite called norfluoxetine has a half-life up to 16 days. So somebody skipping the drug for a week might not even notice anything, subjectively. Paxil's half-life is substantially shorter, at 21 hours, and has no active metabolites.

Lar