Selective serotonin reuptake inhibitors act by modifying the brain levels of the neurotransmitter serotonin that are altered in depression.
The most known selective serotonin reuptake inhibitors are fluoxetine (Prozac), and paroxetine (Seroxat), among others. Along with these, there are other related antidepressants, such as venlafaxine and duloxetine, which also inhibit the reuptake of noradrenaline, another neurotransmitter involved in depression. Duloxetine is the second commercially available serotonin and noradrenaline reuptake inhibitor after venlafaxine.
While it is true that there are not many differences between venlafaxine and duloxetine, we do find these differences most noticeably in relation to sexual problems such as sexual desire, arousal or the effect of orgasm since venlafaxine affects more than duloxetine. It has also been shown that venlafaxine has more side effects than duloxetine and is therefore often used as a supportive medication in the treatment of major depression. These two drugs are used as antidepressants in major depression disorder. When using these antidepressants you have to stop taking them gradually so as not to have the withdrawal syndrome.
These selective serotonin and noradrenaline uptake inhibitors were developed based on the monoaminergic hypothesis and the recognition that antidepressants with dual amplifying action on the serotonergic and noradrenergic systems would be more effective in the treatment of emotional and physical symptoms of the depression compared with selective serotonin reuptake inhibitors.