How Does Bupropion XL Work?Bupropion XL is a norepinephrine and dopamine reuptake inhibitor, or NDRI for short. NDRIs, such as bupropion XL, affect specific chemicals within the brain known as norepinephrine and dopamine. 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 norepinephrine (or dopamine). The chemical enters the gap between the first nerve cell and the one next to it.
When enough norepinephrine or dopamine 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 norepinephrine or dopamine that remains in the gap between the cells. This is called "reuptake."
Normally, this process works without any problems. But when the levels of dopamine and norepinephrine become unbalanced, it can cause a variety of conditions, including depression and seasonal affective disorder. Bupropion XL helps to block the reuptake of norepinephrine and dopamine so that more remains in the space between the brain's nerve cells. This gives the chemicals a better chance of activating the receptors on the next nerve cell.
Currently, the only NDRI antidepressants approved for use are medications containing bupropion. Bupropion XL is a very long-acting version, taken just once a day. Bupropion also comes in several other forms, including:
- Wellbutrin (bupropion hydrochloride), a short-acting version
- Wellbutrin SR® (bupropion SR), a sustained-release version (taken twice a day)
- Aplenzin™ (bupropion hydrobromide), taken once a day
- Zyban® (bupropion SR), a sustained-release version used for smoking cessation.