It is pretty rare but I have personally been on 4-5 serotonergic medications many times with no problems. Either my body tolerates the excess
serotonin very well or I am very, VERY low on
serotonin which could actually explain a lot, lol. Insomnia, while certainly not the worst possible side effect, is pretty annoying. With that said, I may call my local pharmacist today and ask him. I am still hoping someone on here may have experience using doxepin with fluoxetine and or duloxetine.