Effexor and Wellbutrin are both medications that may be prescribed for depression. Effexor is the brand name for the generic drug called venlafaxine and Wellbutrin is the brand name for the generic drug bupropion. Effexor is also approved by the United States Food and Drug Administration (FDA) for the treatment of generalized anxiety disorder, social anxiety and panic disorder. Both drugs work in a generally similar manner, but they act on different chemicals in the brain. Understanding their different functions and side effects can help you and your doctor decide which may be the best choice for you.
Imbalances in certain chemicals within the brain can lead to depression and anxiety. Effexor belongs to a group of antidepressants called serotonin and norepinephrine reuptake inhibitors (SNRIs) or dual reuptake inhibitors. Serotonin and norepinephrine are chemicals released from nerve cells in the brain. They are later taken back into the nerves, where they are broken down and destroyed. Effexor blocks this reuptake, causing the levels of both chemicals to rise in the brain. These increased levels help reduce depression and anxiety.
Wellbutrin belongs to a separate group of antidepressants called norepinephrine and dopamine reuptake inhibitors (NDRIs). Like Effexor, it blocks the reuptake of certain chemicals into nerve cells in the brain. But the chemicals affected by Wellbutrin are norepinephrine and dopamine. The difference in chemicals may explain why Wellbutrin is not used for anxiety.
Effexor: Common Side Effects
All medications have possible side effects. The most common side effect of Effexor is nausea, occurring in about 30 percent of people according to the FDA prescribing information. Dry mouth, decreased appetite, diarrhea and constipation are other relatively common gastrointestinal effects. Effexor also causes sweating, dizziness, insomnia and sleepiness in a significant number of people. Many antidepressants can cause sexual side effects, and Effexor appears to fall in the middle range for these issues. About 5 to 10 percent of people taking Effexor notice problems with sexual function.
Wellbutrin: Common Side Effects
Like Effexor, gastrointestinal effects are common with Wellbutrin. Of these, dry mouth is the most frequent, occurring in about 24 percent of people taking Wellbutrin for major depressive disorder according to the FDA prescribing information. Nausea is the second most common, occurring in about 18 percent of people. Decreased appetite, diarrhea and constipation are other relatively frequent gastrointestinal effects. Headaches are common with Wellbutrin. Like Effexor, Wellbutrin may cause sweating and insomnia. Anxiety is more common with Wellbutrin than with Effexor, which is not surprising since Effexor is used to treat anxiety. Sleepiness is unusual with Wellbutrin. Wellbutrin is less likely to cause sexual problems than many antidepressants, including Effexor.
Serious Side Effects
The FDA has issued a warning that all antidepressants, including Wellbutrin and Effexor, may increase the risk of suicidal thoughts or behaviors, especially in children, teenagers and young adults. All antidepressants may also increase the possibility of a manic episode, especially in people with bipolar depression. Both Effexor and Wellbutrin can cause high blood pressure, seizures and allergic reactions.
Each drug also has its own potential serious side effects. Serotonin syndrome, a life-threatening condition caused by too much serotonin, may occur with Effexor. This syndrome can produce a number of symptoms, including a very fast heart rate, high temperature, confusion and coma. Effexor may also cause excessive bleeding and worsening of certain types of glaucoma. Wellbutrin may damage the liver.
As many types of antidepressants cause people to gain weight, the effects of Wellbutrin and Effexor on weight are important to consider. Among all antidepressants, Wellbutrin is most likely to cause actual weight loss. According to a study published in "The Journal of Clinical Psychiatry" in October 2010, people taking Wellbutrin lost about 2 pounds on average during the first 3 months of treatment and close to 4 pounds during long-term treatment. People taking Effexor lost about 1 pound during the first 3 months. Not enough research has been done to determine the long-term effects of Effexor on weight.
The effects of antidepressant medications vary greatly from person to person. It is not possible to know in advance which drug will give you the greatest benefit and fewest side effects. You may have to try a number of antidepressants before finding the one that is best for you.
Reviewed by: Mary D. Daley, M.D.