Side effects of prozak


Generic Name: fluoxetine (floo OX e teen)
Brand Names: PROzac, PROzac Weekly, PROzac Pulvules, Sarafem

Medically reviewed by Kaci Durbin, MD Last updated on Dec 20, 2018.

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What is fluoxetine?

Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) antidepressant. Fluoxetine affects chemicals in the brain that may be unbalanced in people with depression, panic, anxiety, or obsessive-compulsive symptoms.

Fluoxetine is used to treat major depressive disorder, bulimia nervosa (an eating disorder), obsessive-compulsive disorder, panic disorder, and premenstrual dysphoric disorder (PMDD).

Fluoxetine is sometimes used together with another medication called olanzapine (Zyprexa) to treat manic depression caused by bipolar disorder. This combination is also used to treat depression after at least 2 other medications have been tried without successful treatment of symptoms.

If you also take olanzapine (Zyprexa), read the Zyprexa medication guide and all patient warnings and instructions provided with that medication.

Important information

You should not use fluoxetine if you also take pimozide or thioridazine, or if you are being treated with methylene blue injection.

Do not use fluoxetine if you have used an MAO inhibitor in the past 14 days (such as isocarboxazid, rasagiline, selegiline, phenelzine, or transcypromine). Do not use fluoxetine with thioridazine, linezolid, pimozide, or methylene blue injection.

You must wait at least 14 days after stopping an MAO inhibitor before you can take fluoxetine. You must wait 5 weeks after stopping fluoxetine before you can take thioridazine or an MAOI.

Some young people have thoughts about suicide when first taking an antidepressant. Stay alert to changes in your mood or symptoms.

Fluoxetine could impair judgment, thinking, or motor skills. Use caution when operating machinery.

Report any new or worsening symptoms to your doctor, such as: mood or behavior changes, anxiety, panic attacks, trouble sleeping, or if you feel impulsive, irritable, agitated, hostile, aggressive, restless, hyperactive (mentally or physically), more depressed, or have thoughts about suicide or hurting yourself.

Before taking this medicine

Do not use fluoxetine if you have taken an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, phenelzine, rasagiline, selegiline, and tranylcypromine. You must wait at least 14 days after stopping an MAO inhibitor before you can take fluoxetine. You must wait 5 weeks after stopping fluoxetine before you can take thioridazine or an MAOI.

You should not use fluoxetine if you are allergic to it, if you also take pimozide or thioridazine, or if you are being treated with methylene blue injection.

Tell your doctor about all other antidepressants you take, especially Celexa, Cymbalta, Desyrel, Effexor, Lexapro, Luvox, Oleptro, Paxil, Pexeva, Symbyax, Viibryd, or Zoloft.

Some medicines can interact with fluoxetine and cause a serious condition called serotonin syndrome. Be sure your doctor knows about all other medicines you use. Ask your doctor before making any changes in how or when you take your medications.

To make sure fluoxetine is safe for you, tell your doctor if you have:

  • cirrhosis of the liver;

  • kidney disease;

  • diabetes;

  • narrow-angle glaucoma;

  • seizures or epilepsy;

  • bipolar disorder (manic depression);

  • a history of drug abuse or suicidal thoughts; or

  • if you are being treated with electroconvulsive therapy (ECT).

Some young people have thoughts about suicide when first taking an antidepressant. Your doctor should check your progress at regular visits. Your family or other caregivers should also be alert to changes in your mood or symptoms.

Taking an SSRI antidepressant during pregnancy may cause serious lung problems or other complications in the baby. However, you may have a relapse of depression if you stop taking your antidepressant. Tell your doctor right away if you become pregnant. Do not start or stop taking fluoxetine during pregnancy without your doctor’s advice.

Fluoxetine can pass into breast milk. Tell your doctor if you are breast-feeding a baby.

Fluoxetine is not approved for use by anyone younger than 18 years old.

How should I take fluoxetine?

Take fluoxetine exactly as prescribed by your doctor. Follow all directions on your prescription label. Your doctor may occasionally change your dose. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Do not crush, chew, break, or open a delayed-release capsule. Swallow it whole.

Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.

To treat premenstrual dysphoric disorder, the usual dose of fluoxetine is once daily while you are having your period, or 14 days before you expect your period to start. Follow your doctor’s instructions.

It may take up to 4 weeks before your symptoms improve. Keep using the medication as directed and tell your doctor if your symptoms do not improve.

Do not stop using fluoxetine suddenly, or you could have unpleasant withdrawal symptoms. Ask your doctor how to safely stop using fluoxetine.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

If you miss a dose of Prozac Weekly, take the missed dose as soon as you remember and take the next dose 7 days later. However, if it is almost time for the next regularly scheduled weekly dose, skip the missed dose and take the next one as directed. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking fluoxetine?

Drinking alcohol can increase certain side effects of fluoxetine.

Ask your doctor before taking a nonsteroidal anti-inflammatory drug (NSAID) for pain, arthritis, fever, or swelling. This includes aspirin, ibuprofen (Advil, Motrin), naproxen (Aleve), celecoxib (Celebrex), diclofenac, indomethacin, meloxicam, and others. Using an NSAID with fluoxetine may cause you to bruise or bleed easily.

This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Fluoxetine side effects

Get emergency medical help if you have signs of an allergic reaction to fluoxetine: skin rash or hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Report any new or worsening symptoms to your doctor, such as: mood or behavior changes, anxiety, panic attacks, trouble sleeping, or if you feel impulsive, irritable, agitated, hostile, aggressive, restless, hyperactive (mentally or physically), more depressed, or have thoughts about suicide or hurting yourself.

Call your doctor at once if you have:

  • blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;

  • signs of high levels of serotonin in the body–agitation, hallucinations, fever, fast heart rate, overactive reflexes, nausea, vomiting, diarrhea, loss of coordination, fainting;

  • signs of low levels of sodium in the body–headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;

  • very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out; or

  • severe skin reaction–fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Common fluoxetine side effects may include:

  • sleep problems (insomnia), strange dreams;

  • headache, dizziness, vision changes;

  • tremors or shaking, feeling anxious or nervous;

  • pain, weakness, yawning, tired feeling;

  • upset stomach, loss of appetite, nausea, vomiting, diarrhea;

  • dry mouth, sweating, hot flashes;

  • changes in weight or appetite;

  • stuffy nose, sinus pain, sore throat, flu symptoms; or

  • decreased sex drive, impotence, or difficulty having an orgasm.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect fluoxetine?

Taking fluoxetine with other drugs that make you sleepy or slow your breathing can cause dangerous side effects or death. Ask your doctor before taking a sleeping pill, narcotic pain medicine, prescription cough medicine, a muscle relaxer, or medicine for anxiety, depression, or seizures.

Many drugs can interact with fluoxetine. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any you start or stop using, especially:

  • any other antidepressant;

  • St. John’s Wort;

  • tryptophan (sometimes called L-tryptophan);

  • a blood thinner – warfarin, Coumadin, Jantoven;

  • medicine to treat anxiety, mood disorders, thought disorders, or mental illness – amitriptyline, buspirone, desipramine, lithium, nortriptyline, and many others;

  • medicine to treat ADHD or narcolepsy – Adderall, Concerta, Ritalin, Vyvanse, Zenzedi, and others;

  • over-the-counter pain medications including ibuprofen, acetaminophen, aspirin, or similar medications;

  • migraine headache medicine – rizatriptan, sumatriptan, zolmitriptan, and others; or

  • narcotic pain medicine – fentanyl, tramadol.

This list is not complete and many other drugs can interact with fluoxetine. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Give a list of all your medicines to any healthcare provider who treats you.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use fluoxetine only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Copyright 1996-2020 Cerner Multum, Inc. Version: 24.01.

Related questions

  • If I’m on fluoxetine, what can I take for a bad cough associated with a cold or strep throat?
  • What is the difference between Prozac and Zoloft?

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  • Fluoxetine Capsules and Tablets
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  • Fluoxetine Delayed-Release Capsules
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Other brands: Prozac, Prozac Weekly, Sarafem, Rapiflux, Selfemra

Professional resources

  • Fluoxetine Hydrochloride (AHFS Monograph)
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What is Prozac (fluoxetine)?

Prozac is selective serotonin reuptake inhibitor (SSRI). It works by blocking the absorption of the neurotransmitter serotonin in the brain.

Regulating the amount of serotonin helps brain cells transmit messages to each other. This results in a better and more stable mood. It also results in more neurons being present in a region of the brain called the “dentate gyrus,” part of the hippocampal formation. The hippocampus plays a role in forming memories.

The U.S. Food and Drug Administration (FDA) currently approves Prozac for acute and maintenance treatment of major depressive disorder (MDD), obsessive compulsive disorder (OCD), bulimia nervosa, and panic disorder, with or without agoraphobia.

Prozac is normally used alone. However, fluoxetine combined with olanzapine (OFC) can also be used to treat depressive episodes in people with bipolar disorder. Fluoxetine combined with olanzapine is known as Symbyax. This combination can also help people with treatment-resistant depression.

Some doctors may prescribe Prozac “off-label” to treat anxiety, premature ejaculation, obesity, and binge-eating disorder.


Prozac can be used to treat depression in adults. It can also be used for children and adolescents from the age of 10 to 19 years with severe, persistent depression. However, the National Institute of Mental Health (NIMH) urge caution, as a small subset of adolescents have shown suicidal tendencies after using it.

A review comparing the effectiveness of Prozac with other antidepressants found that it appears to be similarly effective, and possibly better tolerated. However, the authors concluded that more research is needed, as a number of factors made an exact comparison difficult.

Findings reported in Progress in Neuro-Psychopharmacology and Biological Psychiatry have suggested that some patients’ depression does not respond to treatment with the SSRIs paroxetine (Paxil) and citalopram (Celexa), because of a specific genetic factor. These patients, say the researchers, may benefit from a switch to Prozac.

Panic disorder

A number of studies have suggested that Prozac can reduce the incidence of panic attacks in people with panic disorder.

In one study, around 7 percent of patients reported experiencing increased anxiety in the first few weeks after they started using Prozac, compared with 9 percent who took a placebo. However, compared with the overall benefits, this is considered small enough that Prozac is still “safe and effective” as a treatment for anxiety and panic attacks.

Obsessive-compulsive disorder (OCD)

SSRIs normally need to be taken for at least 11 weeks before a person with OCD experiences any benefits. Patients with OCD normally use an SSRI such as Prozac for at least a year, depending on the individual’s needs and situation.

A study published in the Journal of the American Academy of Child and Adolescent Psychiatry, concluded that a 20 to 60 milligram (mg) dose of fluoxetine was effective in treating children and adolescents with OCD. Participants also tolerated the drug well.

Bulimia nervosa

Researchers reported in The American Journal of Psychiatry that for patients with bulimia nervosa who had not responded to psychological treatment, fluoxetine may be a useful intervention. It may provide benefits for bulimia if it is taken for up to a year.

Prozac was so popular after its debut in 1988 that it inspired not one but two best-selling books: Listening to Prozac and Prozac Nation (which was turned into a movie starring Christina Ricci).

It was the first SSRI, or selective-serotonin reuptake inhibitor, approved by the Federal Drug Administration, and 20 later, Prozac is still one of the top five psychiatric drugs prescribed to American adults dealing with depression and anxiety.

While most SSRIs are safe and easily tolerated, they are still psychoactive drugs—so yes, there are Prozac side effects you should know about.

Prozac stays in your system for one to two weeks, says Alison Hermann, M.D., a clinical psychiatrist at Weill Cornell Medicine and New York-Presbyterian Hospital. Which means: “If you’re someone who forgets to take your meds every day, that’s great, says Hermann. “If you’re having side effects, that can make things extra difficult.”

If you decide to try Prozac to manage your depression or anxiety, keep an eye out for these side effects.

1. GI Distress

“By far, the most common Prozac side effects are gastrointestinal, mostly nausea and diarrhea,” says Hermann. Fun fact: “There are actually more cells that have serotonin receptors on them in your gut than there are in the brain, and since Prozac works on the serotonin system, that area can be sensitive to having more serotonin around.” These side effects tend to occur early on in treatment, and can be minimized by starting with a low dose or taking the meds with food.

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2. Changes in Arousal

No, we’re not talking about sex—yet. “Some people taking an SSRI for the first time may feel tired or a bit sedated initially, or the opposite, a little revved up or jittery,” says Murrough. “It basically occurs as the neurotransmitters in the brain get used to being exposed to something new.” Again, starting on a low dose can help mitigate this side effect.

“With serotonin syndrome, you would have symptoms like fever, agitation, increased reflexes, tremors, and you’d likely have to go to the emergency room.”

3. Suicidal Thinking

Antidepressants and anti-anxiety medications are meant to help you feel better, but in some people, they can actually increase depressive thoughts. “The FDA has issued a black box warning—its strictest warning—that antidepressants can actually increase suicidal thinking in young adults and children,” says Murrough. Yes, it’s rare, but if you’re going to the doctor for depression and the medication makes you feel worse, you should absolutely talk to your doc ASAP.

4. Sexual Side Effects

These side effects tend to present once you’re on a stable dose—and the higher the dose, the more likely you are to experience them. “It can run the gamut, whether you’re a man or a woman: decreased libido, decreased genital sensations, impotence, or difficulty having an orgasm,” says Hermann. “We’re not quite sure why this happens, and anxiety and depression affect sexual functioning and sexual interest, so it can be difficult to figure out if it’s the mental disorder or the medication to blame.” Still, talk to your doc if your sex drive takes a dive.

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5. Serotonin Syndrome

This is a rare side effects of medications that work on serotonin, like Prozac, but can occur if you’re on more than one drug that affects serotonin levels—which can overload your system. “With serotonin syndrome, you would have symptoms like fever, agitation, increased reflexes, tremors, sweating, dilated pupils, and diarrhea, and you’d likely have to go to the emergency room,” says Hermann.

6. Changes in Weight or Appetite

A study published in the journal JAMA Psychiatry found that people taking Prozac gained an average of a pound and a half over the course of a year of taking the medication.

If you notice more bruises than normal or cuts that won’t stop bleeding, definitely bring that to your doctor’s attention.

7. Low Sodium Levels

“When you’re on any SSRIs, the medication can cause your kidneys to excrete more sodium,” says Hermann. “That can lead to symptoms like headaches, confusion, slurred speech, and general weakness.” She recommends that anyone taking antidepressants or anti-anxiety drugs have at least yearly blood work done to check electrolyte levels.

8. Trouble Sleeping

Like most SSRIs, Prozac can have an effect on sleep quality. “Any time you take a medication that affects the brain, there’s a potential for alterations in arousal,” says Murrough. That can manifest in abnormal dreams, difficulty falling or staying asleep, or even nighttime sweats.

9. Increased or Unusual Bruising or Bleeding

“SSRIs can affect the way platelets aggregate to stop bleeding in some people,” says Murrough. This is almost nonexistent in the general population, but there is a risk of bleeding more easily while taking Prozac. This would be most likely to occur in older patients, says Murrough—but if you notice more bruises than normal or cuts that won’t stop bleeding, definitely bring that to your doctor’s attention.

Ashley Mateo Ashley Mateo is a writer, editor, and UESCA-certified running coach who has contributed to Runner’s World, Bicycling, Women’s Health, Health, Shape, Self, and more.

Before taking fluoxetine,

  • tell your doctor and pharmacist if you are allergic to fluoxetine, any other medications, or any of the ingredients in fluoxetine preparations. Ask your pharmacist for a list of the ingredients.
  • tell your doctor if you are taking pimozide (Orap), thioridazine, or a monoamine oxidase (MAO) inhibitor such as isocarboxazid (Marplan), linezolid (Zyvox), methylene blue, phenelzine (Nardil), selegiline (Eldepryl, Emsam, Zelapar), and tranylcypromine (Parnate), or if you have stopped taking a monoamine oxidase inhibitor within the past 2 weeks. Your doctor will probably tell you that you should not take fluoxetine. If you stop taking fluoxetine, you should wait at least 5 weeks before you begin to take thioridazine or a monoamine oxidase inhibitor.
  • tell your doctor and pharmacist what other prescription and nonprescription medications and vitamins you are taking or plan to take. Be sure to mention any of the following: alprazolam (Xanax); amiodarone (Pacerone, Nexterone); certain antibiotics such as erythromycin (E.E.S, Eryc, Ery-tab), gatifloxacin, moxifloxacin (Avelox), and sparfloxacin (no longer available in U.S., Zagam); amphetamines such as amphetamine (in Adderall), dextroamphetamine (Dexedrine, Dextrostat, in Adderall), and methamphetamine (Desoxyn); anticoagulants (‘blood thinners’) such as warfarin (Coumadin, Jantoven); antidepressants (mood elevators) such as amitriptyline (Elavil), amoxapine, clomipramine (Anafranil), desipramine (Norpramin), doxepin, imipramine (Tofranil), nortriptyline (Pamelor), protriptyline (Vivactil), and trimipramine (Surmontil); aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil, Motrin) and naproxen (Aleve, Naprosyn); buspirone; clopidogrel (Plavix); diazepam (Valium); digoxin (Lanoxin); diuretics (‘water pills’); dolasetron (Anzemet); fentanyl (Duragesic, Lazanda, Subsys, others); flecainide (Tambocor); insulin or oral medications for diabetes; lithium (Lithobid); medications for anxiety and Parkinson’s disease; medications for mental illness such as chlorpromazine, clozapine (Clozaril, Versacloz), droperidol (Inapsine), haloperidol (Haldol), iloperidone (Fanapt), and ziprasidone (Geodon); methadone (Methadose); medications for migraine headaches such as almotriptan (Axert), eletriptan (Relpax), frovatriptan (Frova), naratriptan (Amerge), rizatriptan (Maxalt), sumatriptan (Imitrex), and zolmitriptan (Zomig); pentamidine (Pentam); quinidine (in Nuedexta); procainamide; medications for seizures such as carbamazepine (Epitol, Tegretol, Teril) and phenytoin (Dilantin, Phenytek); sedatives; sleeping pills; other selective serotonin-reuptake inhibitors such as citalopram (Celexa), fluoxetine (Prozac, Sarafem, Selfemra), or fluvoxamine (Luvox); serotonin–norepinephrine reuptake inhibitors (SNRI) medications desvenlafaxine (Khedezla, Pristiq), duloxetine (Cymbalta), levomilnacipran (Fetzima), and venlafaxine; sotalol (Betapace, Sorine); tramadol (Ultram); tranquilizers; and vinblastine (Velban). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor what nutritional supplements and herbal products you are taking, especially products that contain St. John’s wort or tryptophan.
  • tell your doctor if you or anyone in your family has or has ever had a prolonged QT interval (a rare heart problem that may cause irregular heartbeat, fainting, or sudden death). Also tell your doctor if you have a low level of potassium or magnesium in your blood or are being treated with electroshock therapy (procedure in which small electric shocks are administered to the brain to treat certain mental illnesses). Tell your doctor if you have recently had a heart attack and if you have or have ever had heart failure, diabetes, seizures, or liver or heart disease.
  • tell your doctor if you are pregnant, especially if you are in the last few months of your pregnancy, or if you plan to become pregnant or are breastfeeding. If you become pregnant while taking fluoxetine, call your doctor. Fluoxetine may cause problems in newborns following delivery if it is taken during the last months of pregnancy.
  • you should know that fluoxetine may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.
  • remember that alcohol can add to the drowsiness caused by this medication.
  • you should know that fluoxetine may cause angle-closure glaucoma (a condition where the fluid is suddenly blocked and unable to flow out of the eye causing a quick, severe increase in eye pressure which may lead to a loss of vision). Talk to your doctor about having an eye examination before you start taking this medication. If you have nausea, eye pain, changes in vision, such as seeing colored rings around lights, and swelling or redness in or around the eye, call your doctor or get emergency medical treatment right away.

Managing the Adverse Effects of Antidepressants: Page 2 of 3

Sweating. As many as 20% of patients taking antidepressants experience excessive sweating.8 It is commonly prominent in the scalp, face, neck, and chest and usually occurs with episodic bursts, often persisting throughout treatment. Reboxetine, venlafaxine, and bupropion increase susceptibility, whereas paroxetine and mirtazapine might decrease susceptibility. Several agents have been proposed to treat excessive sweating, based on hypotheses about its pathophysiology: serotonin antagonists, such as cyproheptadine; antiadrenergic agents, such as clonidine; and anticholinergic agents, such as benztropine and glycopyrrolate.

Sexual dysfunction. Antidepressants can affect every aspect of sexual functioning and cause decreased libido, problems with arousal, ejaculatory delay, anorgasmia, and erectile dysfunction. Prevalence rates up to 80% have been reported.9 SSRIs are more likely to cause sexual adverse effects than are noradrenergic drugs. In some patients, sexual adverse effects will disappear spontaneously or improve after dose reduction. Taking a drug holiday, ie, stopping the antidepressant for a few days, has been shown to improve sexual function and satisfaction in approximately half of the patients taking an SSRI with a short half-life, such as sertraline or paroxetine.10

The addition of sildenafil or tadalafil is an effective strategy for men with antidepressant-induced erectile dysfunction.11 In women, transdermal testosterone increases the frequency of satisfactory sexual events12; adding a higher dose of bupropion (300 mg/d) also seems to improve sexual function.11 Although generally considered to resolve on cessation of the drug, SSRI- and SNRI-emergent sexual adverse effects may persist after drug discontinuation in some patients.13 Psychological processes probably play a role in the persistence of these sexual dysfunctions, and they should be addressed.

Sedation. Often wanted but frequently annoying, sedation is more commonly associated with TCAs and mirtazapine than with SSRIs and SNRIs. In the event that dose reduction or bedtime dosing does not help, switching to a less sedating alternative, such as bupropion, an SSRI, or an SNRI, can be considered. In the case of excessive sleepiness and fatigue, adjunctive modafinil can be considered to improve wakefulness.

A dose-related and reversible decrease in motivation and emotional responsivity or detachment, also referred to as apathy or emotional blunting, has been reported, mainly in case reports and predominantly associated with the use of SSRIs.14 In these cases, reducing the dose or switching to another antidepressant, preferably bupropion, may help.

The discontinuation syndrome

A final hurdle to overcome is the discontinuation syndrome, which develops in some patients (5% to 86%) 1 to 7 days following dose reduction or discontinuation of an SSRI or SNRI.15 Typically, patients describe electric shocks in the brain, visual flashes, and headaches. Other symptoms are dizziness, lethargy, light-headedness, insomnia, fatigue, anxiety, agitation, and nausea.

This syndrome has been linked to the half-life of a given SSRI; paroxetine has been involved more often than other SSRIs.16 Tailoring tapering to the individual patient and to the specific antidepressant should reduce the likelihood of experiencing discontinuation symptoms. In some cases, prescribing an SSRI with a longer half-life (eg, fluoxetine) while discontinuing the antidepressant might be helpful.


Maria, who is 58, was treated for depression and anxiety. She has been referred by her primary care physician because her symptoms relapsed during tapering of venlafaxine. She reports, “Two days after tapering, I felt electrical twitches in my head; I have headaches and feel nervous and agitated. I think I am relapsing and will have to take my pills forever.”

Maria is experiencing discontinuation symptoms. Gradual tapering of venlafaxine, taking 37.5 mg every other day, does not prevent severe discontinuation symptoms. Fluoxetine 20 mg/d is prescribed, and venlafaxine is discontinued without any problem. Fluoxetine is then gradually tapered, but about 2 weeks after the final dose, Maria experiences mild discontinuation symptoms (“feeling nervous”). These disappear after another week.

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