Stopping antidepressants, including fluoxetine, can give rise to withdrawal symptoms. To prevent fluoxetine withdrawal, it is best to taper the dosage slowly under medical supervision.

Stopping fluoxetine (Prozac), a type of antidepressant, can cause some people to experience withdrawal symptoms.

Some research indicates that withdrawal, or discontinuation, symptoms are common, affecting more than half of those who stop taking antidepressants.

Fluoxetine withdrawal symptoms can vary in their onset, intensity, and duration.

This article discusses fluoxetine withdrawal symptoms, how long they last, some treatments and techniques to minimize or prevent them, and taking and discontinuing fluoxetine during pregnancy.

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Fluoxetine is a medication that belongs to a class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs).

SSRIs work by increasing the amount of serotonin available to the brain. Serotonin is a hormone and neurotransmitter that promotes positive feelings and stabilizes mood.

The Food and Drug Administration (FDA) has approved the use of fluoxetine in adults for the treatment of:

The FDA has also approved it for the treatment of MDD in children aged 8 years and older.

It can take several weeks after beginning fluoxetine for the symptoms of these conditions to improve.

Fluoxetine is a prescription drug that comes in capsule, tablet, or solution form. In the United States, it is available as a generic drug or under the brand name Prozac.

Fluoxetine withdrawal symptoms may occur when a person stops taking the medication. These symptoms may develop because of the rapid changes in the brain’s serotonin levels following antidepressant cessation.

A 2019 review of existing research reports that 56% of people experience withdrawal effects when stopping various antidepressants. Around 46% of these people report “severe” symptoms.

One of the studies in the review found that out of 95 people who abruptly stopped taking fluoxetine, 67% experienced withdrawal symptoms. However, doctors do not recommend stopping antidepressant use abruptly because it may lead to more severe symptoms.

Other research suggests that fluoxetine may be “particularly unproblematic” when people stop taking it because of its especially long half-life of 96–144 hours (4–6 days).

A drug’s half-life refers to the time it takes for the amount of the medication’s active substance to reduce by half in the body. Antidepressants with a long half-life tend to cause fewer withdrawal symptoms than those with a shorter half-life.

Fluoxetine and other SSRIs may cause the following withdrawal symptoms when a person stops using them:

  • a feeling of detachment
  • a sensation that resembles an electric shock in the head (“brain zaps”) or other strange sensations
  • anxiety
  • depression
  • diarrhea
  • difficulty concentrating
  • dizziness or vertigo
  • fatigue
  • flu-like symptoms, such as chills or body aches
  • involuntary movements
  • a loss of balance or coordination
  • mood changes
  • nausea
  • ringing in the ears, or tinnitus
  • sensory disturbances, such as smelling odors that are not actually there
  • sleep issues, including vivid dreams and nightmares
  • stomach cramps
  • vomiting
  • suicidal thoughts

Withdrawal vs. a return of depressive symptoms

Some of the mood-related symptoms that experts associate with fluoxetine withdrawal may resemble symptoms of depression or another mental health condition.

Experiencing these symptoms does not necessarily mean that someone is having a recurrence of depression.

To help distinguish between withdrawal symptoms and a return of depressive symptoms, it is important to consider when the symptoms first occur and how they develop.

Discontinuation symptoms appear within a few days or weeks of stopping antidepressants, while returning depressive symptoms develop after some weeks and tend to come on gradually.

Discontinuation symptoms will improve as the body adjusts, while returning depressive symptoms will persist or worsen as time goes on.

The severity and duration of fluoxetine withdrawal can vary.

Doctors and professional organizations often say that antidepressant withdrawal symptoms are self-limiting and typically resolve within a couple of weeks.

However, a 2019 review of existing research indicates that this may not always be the case.

Sometimes, symptoms can persist for several weeks or months. In a small number of cases, people may experience withdrawal symptoms for over a year.

One of the studies in the review found that 40% of people who abruptly stopped taking fluoxetine still experienced symptoms 6 weeks after discontinuation.

The researchers did not follow up with the participants after this time, so it is not possible to say how long these effects lasted.

Most people, however, will likely feel better within a few weeks.

There are several treatment and self-care options available to help those who wish to stop taking fluoxetine do so safely and in a way that minimizes discomfort.

These options include:

  • Discussing discontinuation with a doctor: Always discuss stopping antidepressants with a doctor before making any changes. Suddenly stopping a medication increases the risk of severe symptoms.
  • Tapering slowly: Usually, doctors advise that people reduce their dosage slowly, typically over 4 weeks or longer — particularly if they are taking higher dosages or have been taking the medication long term.
  • Managing withdrawal symptoms with other medications: A doctor may sometimes prescribe treatments for nausea, flu-like symptoms, sleep problems, or other withdrawal effects.
  • Visiting a doctor for regular follow-ups: Undergoing regular check-ups during the withdrawal process can help the person manage their symptoms and allow the doctor to monitor for a recurrence of depression.
  • Attending psychotherapy: Trying psychotherapies such as cognitive behavioral therapy or mindfulness-based cognitive therapy may help a person discontinue antidepressants without relapsing.
  • Making healthy lifestyle choices: Getting regular exercise, eating a good diet, managing stress, and getting adequate rest and sleep can all help a person manage the symptoms of depression and some of the effects of discontinuing antidepressants.

The FDA has classed fluoxetine as a category C drug. It advises that people should take it during pregnancy only when the potential benefit to the pregnant person justifies the potential risk to the fetus.

For some people, fluoxetine and other SSRIs are important treatments that they must continue during their pregnancy to prevent the return of depressive symptoms.

The National Alliance on Mental Illness advises that people who become pregnant while taking this drug should inform a doctor.

Withdrawal symptoms in pregnant people are likely to be similar to those in the general population, and the management techniques are also likely to be similar.

A person should contact a doctor if they:

  • are experiencing unwanted side effects from antidepressant use and wish to discuss other options
  • wish to stop taking fluoxetine in a safe manner and under medical supervision
  • experience withdrawal symptoms after stopping fluoxetine

People should call a doctor if the side effects are severe or call 911 if they feel life threatening.

Long-term use of fluoxetine is safe if a person takes it as their doctor directs.

However, it may also cause side effects with long-term use. These side effects may include sexual dysfunction, nausea, a loss of appetite, and sleep issues. These issues may cause some people to want to stop treatment with fluoxetine.

Other people may wish to stop using it because they feel better now, because they have become pregnant, or because of something else.

Stopping antidepressants following long-term use may increase the risk of having withdrawal symptoms.

Some research indicates that all antidepressants can cause withdrawal symptoms if a person takes them for longer than 6 weeks — particularly if they stop or rapidly reduce their dosage.

Those who have been taking fluoxetine long term should work with a doctor to find treatments and strategies to minimize potential withdrawal effects. It is also important to monitor for a return of depressive symptoms.

Stopping fluoxetine can cause several withdrawal symptoms, including flu-like symptoms, digestive issues, sleep problems, and mood changes.

However, several strategies and treatments can reduce or prevent such discontinuation symptoms.

People should work with a doctor to come up with a plan that best meets their needs.