Paroxetine, (-)-trans-4-(4-fluorophenyl)-3-[[3,4-(methyldioxy)phenoxy]methyl]-piperidine. This product is a selective 5-HT reuptake inhibitor. It has no obvious effect on other transmitters at usual doses. It increases the concentration of 5-HT in the synaptic cleft by preventing the reuptake of 5-HT, resulting in an antidepressant effect.