Bupropion SR

People who suffer from depression or have problems quitting smoking may benefit from bupropion SR. The medication works by helping to block the reuptake of two chemicals in the brain known as norepinephrine and dopamine. Most people tolerate bupropion SR well, and even when side effects occur, they are usually minor. Some side effects of bupropion SR include nausea, dizziness, and insomnia. Bupropion SR comes in tablet form and it is usually taken twice a day.

 

What Is Bupropion SR?

Bupropion SR (Wellbutrin SR® or Zyban®) is a prescription medicine used for the treatment of depression (also known as major depression or clinical depression). It is also used for smoking cessation (to help people stop smoking). Bupropion SR is a "sustained release" version of bupropion, which means that it is long-acting. Wellbutrin SR and Zyban are very similar medications, except that Wellbutrin SR is approved for depression while Zyban is approved for smoking cessation.
 
(Click What Is Bupropion SR Used For? for more information on what bupropion SR is used for, including possible off-label uses.)
 

Who Makes Bupropion SR?

Wellbutrin SR and Zyban are manufactured by GlaxoSmithKline. Generic bupropion SR is made by several manufacturers.
 

How Does Bupropion SR Work?

Bupropion SR is a norepinephrine and dopamine reuptake inhibitor, or NDRI for short.
 NDRIs, such as bupropion SR, affect specific chemicals within the brain known as norepinephrine and dopamine. Norepinephrine and dopamine 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 norepinephrine (or dopamine) 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 cells. This is called "reuptake."
 
Normally, this process works without any problems. However, when the levels of dopamine and norepinephrine become unbalanced, it can cause a variety of conditions, including depression and seasonal affective disorder. Bupropion SR 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 norepinephrine and dopamine a better chance of activating the receptors on the next nerve cell. This seems to help with depression symptoms and also seems to help people quit smoking.
 
Currently, the only NDRI antidepressants approved for use are medications containing bupropion. Bupropion SR is a sustained-release version of bupropion, usually taken twice a day. Bupropion also comes in other forms, including:
 
  • Wellbutrin® (bupropion hydrochloride), a short-acting version, taken three or four times a day
  • Wellbutrin XL® (bupropion XL), the longest-acting version, taken once a day.
     
(Bupropion SR Continued: Page 2)
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Written by/reviewed by: Kristi Monson, PharmD; Arthur Schoenstadt, MD
Last reviewed by: Kristi Monson, PharmD;