Side Effects That Might Occur Switching from Lexapro to Cymbalta

Depression is a condition that affects millions of Americans on a daily basis, with varying degrees of intensity. Consequently, drug companies are constantly formulating and testing new medications that may treat depression more effectively than the commonly used SSRIs (selective serotonin reuptake inhibitors) 1. Manufacturers started looking towards other neurotransmitters, such as norephinephrine, to treat the condition more effectively. Switching from an SSRI such as Lexapro to Cymbalta may cause some unwanted side effects 3.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.

What is an SSRI?

According to the Mayo Clinic, selective serotonin reuptake inhibitors like Lexapro are characterized by targeting only one of the brain's neurotransmitters associated with depression, serotonin 1. Drugs of this class work by blocking receptors in the brain from taking back serotonin, resulting in more being present in the brain. It is widely believed that in doing so, mood is elevated. Drugs of this family, however, are not a guarantee that your depression will be alleviated as there are a large number of people who have "treatment resistant depression." For these individuals, there are other drugs available.


Cymbalta, like Lexapro, works as a reuptake inhibitor of serotonin 3. Unlike Lexapro, however, Cymbalta works as a reuptake inhibitor of another neurotransmitter, norephinephrine, making it a SSNRI 3. Norepinephrine, according to, is similar to adrenaline and directly affects mood and energy levels 3. It does so by "constricting the blood vessels and increasing blood pressure and blood glucose (sugar) levels." Thus, treatment that includes preventing the reuptake of this neurotransmitter will increase energy levels and help enhance mood for those who are not responding to serotonin treatment alone.

Switching from Lexapro

Since Lexapro is strictly an SSRI, it does not in any way affect norephinephrine levels. If your physician has recommended switching you to Cymbalta, there are a few side effects that can occur that may be bothersome 3. If you have been taking Lexapro for over a month, chances are your levels of serotonin are already higher than normal, so switching to Cymbalta will most likely not cause any SSRI side effects 3. It will, however, cause side effects related to adding a norepinephrine reuptake inhibitor to your medication regimen.

Possible SSNRI Side Effects states that side effects related to increasing norepinephrine levels include:

  • but are not limited to: shaking
  • neurosis
  • anxiety
  • trouble sleeping
  • anger
  • change in mood or behavior
  • grinding of teeth
  • hyperactivity
  • others 3

These side effects are easy to understand as norepinehphrine is directly related to energy levels. These effects will go away after taking the drug for an extended period of time but for many cause them to discontinue using the drug.

Coping with Side Effects

As you have been taking Lexapro, you will most likely not feel the common side effects affiliated with serotonin reuptake inhibitors such as dry mouth and increased sweating 1. It's important to keep in mind that Cymbalta works differently than Lexapro and may result in feeling a few of the SSRI side effects, although typically on a weaker level 3.


The effects of switching to an anti-depressant that works on two neurotransmitters as opposed to one is beneficial if you have not experienced any help from Lexapro. Cymbalta could hold the answer to your depression, if you are willing to dedicate the time necessary for this drug to work 3. If side effects are troublesome or affecting your life negatively, speak to your physician immediately as he may want to change you a different drug or a combination of an SSRI (such as Lexapro) in conjunction with another medication that works solely on norepinephrine, such as Wellbutrin. For some, taking two separate medications results in fewer side effects.