Subjective trials show that the psychoactive effects of MDMA are not
affected by taking fluoxetine first. Serotonin re-uptake inhibitors block
MDMA neurotoxicity. Since fluoxetine is a serotonin re-uptake inhibitor,
this implies that the desired effect of MDMA may be enjoyed without its
neurotoxic effects.
Three were experienced MDMA users who took 20mg fluoxetine 40-60 minutes
before large doses of MDMA, 300-450 mg including booster doses. The sense
of euphoria and closeness was unaffected. There was a greater sense of
calmness but less increase in energy. Side effects normally felt such as
jaw clench were less than normal, though nausea was worse. Two found it
easier to sleep afterwards. Next-day fatigue was considerably less than
normal, even for the one who found sleep as difficult as usual.
The fourth was a woman who had been taking 20mg fluoxetine for the previous
10 days. It was her first MDMA experience and her description of it was
typical, implying that fluoxetine did not effect it.
The paper concludes that these cases "argue against the view that serotonin
release is the basis for MDMA's psychoactive action", since this is
prevented by pre-treatment with fluoxetine. This is supported by the fact
that drugs such as fenfluramine do not produce similar psychoactive effects
to MDMA.
