SNRIs such as Pristiq act on specific chemicals within the brain known as serotonin and norepinephrine. These are two of several chemicals used to send messages from one nerve cell to another.
As a message travels down a nerve, it causes the end of the cell to release serotonin or norepinephrine. The chemical then enters the gap between the first nerve cell and the one next to it. When enough serotonin or norepinephrine reaches the second nerve cell, it activates receptors on the cell and the message continues on its way. The first cell then quickly absorbs any serotonin or norepinephrine that remains in the gap between cells. This is called "reuptake."
Normally, this process works without any problems. When the levels of serotonin or norepinephrine become unbalanced, however, it can cause a variety of conditions, including depression. Pristiq helps block the reuptake of serotonin and norepinephrine so more remains in the space between the brain's nerve cells. This gives the serotonin and norepinephrine a better chance of activating the receptors on the next nerve cell.
Pristiq is not approved for use in children or teenagers. Talk to your healthcare provider about the risks and benefits of using the drug in such age groups.
On occasion, your healthcare provider may recommend Pristiq for something other than the conditions listed in this article. This is called an "off-label" use. Because Pristiq is closely related to venlafaxine (Effexor®, Effexor® XR), it may be useful for some of the conditions that venlafaxine is used to treat, such as: