Fetzima (levomilnacipran) is a prescription drug used to treat major depressive disorder (also called depression) in adults. Fetzima can cause side effects that range from mild to serious. Examples include sweating, nausea, and constipation.

Keep reading to learn about the common, mild, and serious side effects Fetzima can cause. For a general overview of the drug, including details about its uses, see this article.

Some people may experience mild to serious side effects during Fetzima treatment. Here are a few examples of the drug’s commonly reported side effects:

* To learn more about this side effect, see the “Side effects explained” section below.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Fetzima, visit MedWatch.

Mild side effects have been reported with Fetzima. These include:

  • sweating and flushing (temporary warmth, redness, or deepening of skin color)
  • nausea and vomiting
  • decreased appetite
  • increased heart rate
  • pounding heartbeat
  • constipation
  • skin rash
  • mild allergic reaction*†

In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist. And do not stop taking Fetzima unless your doctor recommends it.

Fetzima may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction is possible after taking Fetzima, but this side effect wasn’t reported in studies.

Serious side effects have been reported with Fetzima. These include:

If you develop serious side effects while taking Fetzima, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction is possible after taking Fetzima, but this side effect wasn’t reported in studies.

Help is out there

If you or someone you know is in crisis and considering suicide or self-harm, please seek support:

If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.

If you are not in the same household, stay on the phone with them until help arrives.

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Get answers to some frequently asked questions about Fetzima’s side effects.

How do the side effects of Fetzima compare with those of Pristiq?

Fetzima and Pristiq both belong to a group of drugs called serotonin-norepinephrine reuptake inhibitors (SNRIs). Their side effects are almost identical and include the following:

  • nausea
  • constipation
  • sweating
  • sexual dysfunction
  • increased blood pressure and heart rate

Both Fetzima and Pristiq have a boxed warning for the risk of suicidal thoughts and behaviors. If you have other questions about taking Fetzima compared with Pristiq, talk with your doctor or pharmacist.

Is withdrawal a possible side effect of Fetzima?

As with all antidepressants, suddenly stopping Fetzima can lead to withdrawal symptoms, including:

If you need to stop taking Fetzima, talk with your doctor. They can help you avoid most withdrawal symptoms by gradually reducing your dose of the drug.

Does Fetzima cause weight gain?

Weight gain was not a side effect reported in studies of Fetzima, but decreased appetite was. For some people, a reduced appetite may lead to weight loss.

If you have weight concerns during Fetzima treatment, discuss them with your doctor or pharmacist.

Can Fetzima cause long-term side effects?

It’s possible. Long-term side effects include those that may start at any time you’re taking a drug, even if you’ve taken it for a long time. It also includes side effects that may not go away, even after you stop taking the drug.

Examples of long-term side effects reported in Fetzima’s studies include:

  • heart problems
  • bleeding
  • seizure
  • risk of suicidal thoughts and behavior

Talk with your doctor to learn more about possible side effects of Fetzima and how long they may last.

Learn more about some of the side effects Fetzima may cause.

Risk of suicidal thoughts and behavior

Fetzima has a boxed warning for the risk of suicidal thoughts and behavior. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

Suicidal thoughts and behavior were an uncommon side effect reported in studies of this drug. But they are a serious risk with all antidepressants. Suicidal thoughts and behavior may cause symptoms such as:

  • worsening depression or anxiety
  • having thoughts of harming yourself or others
  • taking steps to harm yourself or others
  • sudden and unusual mood changes
  • agitation, restlessness, and irritability
  • violent or angry actions
  • impulsive, aggressive behavior
  • overwhelming, racing feelings or thoughts
  • mania (hyperactivity, talking too much, feeling invincible)
  • panic attacks
  • insomnia

Factors that can increase the risk of suicidal thoughts and behavior when taking this drug include:

  • being age 24 years or under
  • having a history of mental health conditions such as mania, bipolar disorder, or anxiety
  • having a history of suicidal thoughts or actions

What might help

You can ask trusted family, friends, and healthcare professionals to keep an eye out for these symptoms when you begin taking Fetzima. They might be the first to notice any unusual behavior and offer help if needed.

If you have suicidal thoughts or behavior during Fetzima treatment, talk with your doctor right away. If your symptoms feel life threatening, call 911 or your local emergency number and seek immediate medical treatment.

Sexual and erectile dysfunction

Sexual and erectile dysfunction were common side effects reported in studies of Fetzima. Sexual and erectile dysfunction may cause symptoms such as:

  • inability to get or keep an erection
  • issues with ejaculation
  • pain during intercourse
  • inability to have an orgasm
  • lack of interest in sexual activity

Factors that can increase the risk of sexual and erectile dysfunction when taking this medication include:

  • prostate issues
  • stress or fatigue
  • changes in estrogen or testosterone levels
  • blood circulation problems
  • diabetes
  • relationship difficulties

What might help

If you have sexual or erectile dysfunction during Fetzima treatment, talk with your doctor. They can determine whether underlying health problems are a contributing factor and recommend a treatment plan.

Allergic reaction

Like most drugs, Fetzima can cause an allergic reaction in some people. However, this side effect wasn’t reported in studies. Symptoms can be mild to serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin (usually in your eyelids, lips, hands, or feet)
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms. Examples include:

  • an oral antihistamine, such as Benadryl (diphenhydramine)
  • a product you apply to your skin, such as hydrocortisone cream

If your doctor confirms you’ve had a mild allergic reaction to Fetzima, they’ll decide whether you should continue taking it.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Fetzima, they may have you switch to a different treatment.

Keeping track of side effects

During your Fetzima treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking a new drug or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Fetzima affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before taking Fetzima.

Boxed warning: Risk of suicidal thoughts and behavior

Fetzima has a boxed warning for the risk of suicidal thoughts and behavior. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

To learn more, see the “Side effects explained” section above.

Other warnings

Fetzima can sometimes cause harmful effects in people with certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether this drug is a good treatment option for you. Talk with your doctor about your health history before starting Fetzima. Be sure to tell them if any of the following factors apply to you:

  • seizure
  • high blood pressure
  • heart problems or a history of stroke
  • low blood sodium level
  • kidney problems
  • glaucoma
  • urination problems
  • bleeding problems or blood thinner use
  • history of suicidal thoughts or behavior, bipolar disorder, anxiety, depression, mania, or hypomania
  • alcohol use
  • use of other prescriptions, over-the-counter medications, supplements, vitamins, or herbs
  • previous allergic reaction to Fetzima
  • pregnancy
  • breastfeeding

Alcohol and Fetzima

While taking Fetzima, you might feel tired or notice changes in your thinking, decision-making, or reaction speed. Since alcohol may make these side effects worse, it’s best to avoid it during Fetzima treatment.

If you have questions about consuming alcohol while taking Fetzima, talk with your doctor or pharmacist.

Pregnancy and breastfeeding with Fetzima

Fetzima is usually prescribed for someone who’s pregnant or breastfeeding only if the benefits of treatment outweigh the potential risks to the fetus or child.

Pregnancy

Taking Fetzima while you’re pregnant can be harmful to your child. Taking Fetzima in the third trimester of pregnancy can increase the chances of bleeding after giving birth. It can also lead to your child having difficulties with breathing, temperature control, feeding, or other issues as a newborn.

For some women, treating depression with an antidepressant is essential for helping prevent harm to the mother and fetus. If you’re pregnant or planning to become pregnant, talk with your doctor about your treatment options.

If you’re able to become pregnant, your doctor may recommend using a form of birth control during your Fetzima treatment.

If you take this drug while pregnant, consider signing up for the National Pregnancy Registry for Antidepressants by visiting the website or calling 844-405-6185. A pregnancy registry collects information about the safety of certain drugs when taken during pregnancy.

Breastfeeding

It isn’t known whether Fetzima is safe to take while breastfeeding. There’s no information on how much Fetzima passes into breast milk, how it affects milk production, or how it affects breastfed infants. However, infants exposed to similar drugs through breast milk have sometimes had problems with fussiness and not feeding well.

If you’re breastfeeding or planning to do so, talk with your doctor before starting this medication.

Like most drugs, Fetzima can cause a number of side effects that range from mild to serious. But most are temporary and go away after a few days to weeks. If you have questions about side effects Fetzima can cause, talk with your doctor. Examples of questions to help get you started include:

  • Does Fetzima cause bleeding?
  • Will this medication make me tired?
  • Can Fetzima cause hair loss?
  • Does this drug cause memory loss?
  • Can Fetzima make me feel angry?

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Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.