Fluoxetine receptor specificity

When fluoxetine or other effective but less specific serotonin uptake inhibitors are given, a rapid decrease in serotonin turnover occurs and the rate of firing of single neural units in the serotonin rich raphe area of the brain is reduced. This decrease in serotonin turnover and release may be a compensatory mechanism in response to an enhanced action of serotonin on the synaptic receptors. 

SSRIs affect many postsynaptic serotonin receptors (e.g., 5-HT lA, 5-HT ID, 5-HT 2A, 5-HT 2C, and 5HT-3), therefore affecting many neural systems. With the exception of fluoxetine, none of the currently approved SSRIs have metabolites with clinically relevant effects on any of the neural sites. However, every SSRI that has been studied has metabolites with approximately the same activity as the parent drug for the inhibition of specific CYP... 

Serotoninergic receptors, especially 5-HT2 receptors, are implied in depressive and neuropsychiatric pathologies. Many antidepressive drugs, e.g., fluoxetine, paroxetine and citalopram, target these receptors and selectively inhibit serotonin recapture. The development of specific 5-HT2 tracers would enable the effectiveness of these treatments. 

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