Zoloft (sertraline) vs. Prozac (fluoxetine): What's the difference?
- Zoloft (sertraline) and Prozac (fluoxetine) are selective serotonin reuptake inhibitor (SSRI) type antidepressants used to treat depression, obsessive-compulsive disorder (OCD), panic disorder, and premenstrual dysphoric disorder (PMDD).
- Zoloft is also used to treat post-traumatic stress disorder (PTSD) and social anxiety disorder.
- Prozac is also used to treat bulimia, and it is also prescribed in combination with olanzapine (Zyprexa) to treat resistant depression and depression associated with bipolar disorder.
- Side effects of Zoloft and Prozac that are similar include drowsiness/sleepiness, sleep problems (insomnia), nausea, skin rash, loss of appetite, and headache.
- Side effects of Zoloft that are different from Prozac include sleepiness, nervousness, dizziness, tremor, constipation, upset stomach, diarrhea, abnormal ejaculation, decreased interest in sexual activity, dry mouth, increased sweating, and weight loss.
- Side effects of Prozac that are different from Zoloft include anxiety, vasculitis (inflammation of small blood vessels), and increased blood pressure.
- Do not stop using Zoloft or Prozac suddenly, or you could have unpleasant withdrawal symptoms.
What are Zoloft and Prozac?
Zoloft (sertraline) is a selective serotonin reuptake inhibitor (SSRI) type antidepressant used to treat depression, obsessive-compulsive disorder (OCD), panic disorder, post-traumatic stress disorder (PTSD), social anxiety disorder, and premenstrual dysphoric disorder (PMDD). Other SSRIs include fluoxetine (Prozac, Sarafem), paroxetine (Brisdelle, Paxil, Paxil CR, Pexeva), citalopram (Celexa), and fluvoxamine (Luvox CR). Depression may be caused by disturbances in the balance between serotonin and other neurotransmitters. Experts believe that drugs such as Zoloft restore the chemical balance among neurotransmitters in the brain. Selective serotonin inhibitors block the reuptake of serotonin, therefore changing the level of serotonin in the brain. A serotonin balance is reached between attachment to the nearby nerves and reuptake.
Prozac (fluoxetine) is a selective serotonin reuptake inhibitor (SSRI) antidepressant used to treat depression, bulimia, obsessive-compulsive disorder (OCD), panic disorder, and premenstrual dysphoric disorder (PMDD). It is also prescribed in combination with olanzapine (Zyprexa) to treat resistant depression and depression associated with bipolar disorder. Other SSRIs include citalopram (Celexa), paroxetine (Paxil), and sertraline (Zoloft). Prozac affects the neurotransmitters serotonin. Experts believe an imbalance among neurotransmitters is the cause of depression. Prozac works by preventing the reuptake of one neurotransmitter, serotonin, by nerve cells after it has been released. The reduced uptake caused by Prozac increases free serotonin that stimulates nerve cells in the brain.

SLIDESHOW
Learn to Spot Depression: Symptoms, Warning Signs, Medication See SlideshowWhat are the side effects of Zoloft and Prozac?
Zoloft
WARNING
- As demonstrated in short-term studies, antidepressants increased the risk of suicidal thinking and behavior (suicidality) in children and adolescents with depression and other psychiatric disorders. Anyone considering the use of Zoloft or any other antidepressant in a child or adolescent must balance this risk with the clinical need for the antidepressant. Patients who are started on therapy should be closely observed for clinical worsening, suicidal thoughts, or unusual changes in behavior.
The most common side effects of Zoloft are:
- Sleepiness
- Nervousness
- Insomnia
- Dizziness
- Nausea
- Tremor
- Skin rash
- Constipation
- Upset stomach
- Loss of appetite
- Headache
- Diarrhea
- Abnormal ejaculation
- Decreased interest in sexual activity
- Dry mouth
- Increase in sweating, known as diaphoresis
- Weight loss
Possible serious side effects of Zoloft include:
- Irregular heartbeats
- Serious allergic reactions
- Worsening of depression
- Serotonin syndrome
- Hyponatremia
- Abnormal bleeding
- Priapism (prolonged erection)
- Decreased liver function
- Suicidality
- Activation of mania in patients with bipolar disorder
Important side effects are irregular heartbeats, allergic reactions and activation of mania in patients with bipolar disorder.
If Zoloft is discontinued abruptly, some patients experience side effects such as:
- Abdominal cramps
- Fatigue
- Nausea
- Vomiting
- Diarrhea
- Headaches
- Lightheadedness
- Dizziness
- Diminished appetite
- Flu-like symptoms
- Sweating
- Chills
- Sleep disturbances
- Memory impairment
A gradual dose reduction of Zoloft is recommended when therapy is discontinued.
Prozac
WARNING
Antidepressants increased the risk of suicidal thinking and behavior in short-term studies in children and adolescents with depression and other psychiatric disorders. Anyone considering the use of fluoxetine or any other antidepressant in a child or adolescent must balance this risk of suicide with the clinical need. Patients who begin therapy should be closely observed for clinical worsening, suicidal thoughts, or unusual changes in behavior.
Prozac, as with most antidepressants, can cause:
Prozac has been implicated in serious skin rashes and vasculitis (inflammation of small blood vessels).
Increased blood pressure can occur, and blood pressure should be monitored.
Seizures have been reported as has sexual dysfunction.
Prozac and other antidepressants have been associated with angle closure attacks in people with narrow angle glaucoma.
Some patients may experience withdrawal reactions upon stopping Prozac. The dose of Prozac should be gradually reduced when therapy is discontinued. Symptoms of withdrawal include:
What is the dosage of Zoloft vs. Prozac?
Zoloft
The recommended dose of sertraline is 25 to 200 mg once daily. Treatment of depression, OCD, panic disorder, PTSD, and social anxiety disorder is initiated at 25 to 50 mg once daily. Doses are increased at weekly intervals until the desired response is seen.
The recommended dose for PMDD is 50 to 150 mg every day of the menstrual cycle or for 14 days before menstruation.
Zoloft may be taken with or without food.
Prozac
Depression in adults is treated with 20 to 80 mg of Prozac daily. The recommended dose for treating depression in children is 10 to 20 mg daily. After 13 weeks of daily administration, 90 mg once weekly may be effective in some patients.
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What drugs interact with Zoloft and Prozac?
Zoloft
All SSRIs, including Zoloft, should not be taken with any of the monoamine oxidase inhibitor (MAOI) class of antidepressants, for example
- isocarboxazid (Marplan),
- phenelzine (Nardil),
- tranylcypromine (Parnate),
- selegiline (Eldepryl, Emsam, Elazar), and
- procarbazine (Matulane).
Other drugs that inhibit monoamine oxidase include
- linezolid (Zyvox) and
- intravenous methylene blue.
Such combinations may lead to confusion, high blood pressure, tremor, hyperactivity, coma, and death. (A period of 14 days without treatment should lapse when switching between Zoloft and MAOIs.) Similar reactions occur when Zoloft is combined with other drugs for example, tryptophan, St. John's wort, meperidine (Demerol, Meperitab), tramadol (ConZip, Synapryn FusePaq, Ultram) that increase serotonin in the brain.
Cimetidine (Cimetidine Acid Reducer, Tagamet HB ) may increase the levels in blood of Zoloft by reducing the elimination of Zoloft by the liver. Increased levels of Zoloft may lead to more side effects.
Zoloft increases the blood level of pimozide (Orap) by 40%. High levels of pimozide can affect electrical conduction in the heart and lead to sudden death. Therefore, patients should not receive treatment with both pimozide and Zoloft.
Through unknown mechanisms, Zoloft may increase the blood thinning action of warfarin (Coumadin, Jantoven). The effect of warfarin should be monitored when Zoloft is started or stopped.
Prozac
Taking Prozac 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 Prozac. 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
- migraine headache medicine -- rizatriptan, sumatriptan, zolmitriptan
- narcotic pain medicine -- fentanyl, oxycodone, hydrocodone, and others
Taking monoamine oxidase inhibitors (MAOIs) with Prozac may cause a serious (possibly fatal) drug interaction. Avoid taking MAOIs (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, selegiline, tranylcypromine) during treatment with Prozac. Most MAOIs should also not be taken for 2 weeks before and at least 5 weeks after treatment with Prozac. Ask your doctor when to start or stop taking this medication.
The risk of serotonin syndrome/toxicity increases if you are also taking other drugs that increase serotonin. Examples include street drugs such as MDMA/"ecstasy," St. John's wort, certain antidepressants (including other SSRIs such as citalopram/paroxetine, SNRIs such as duloxetine/venlafaxine), tryptophan, among others. The risk of serotonin syndrome/toxicity may be more likely when you start or increase the dose of these drugs.
Many drugs besides Prozac may affect the heart rhythm (QT prolongation), including pimozide and thioridazine, among others. Aspirin can increase the risk of bleeding when used with Prozac. However, if your doctor has directed you to take low-dose aspirin for heart attack or stroke prevention (usually at dosages of 81 to 325 milligrams a day), you should continue taking it unless your doctor instructs you otherwise.
Tell your doctor or pharmacist if you are taking other products that cause drowsiness including alcohol, antihistamines (such as cetirizine, diphenhydramine), drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants, and narcotic pain relievers (such as codeine).
Check the labels on all your medicines (such as allergy or cough-and-cold products), because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.
Are Zoloft and Prozac safe to use while pregnant or breastfeeding?
Zoloft
Use of Zoloft during the third trimester of pregnancy may lead to adverse effects in the newborn.
Use of Zoloft by nursing mothers has not been adequately evaluated.
Prozac
Prozac should only be used during pregnancy if the potential benefit justifies the potential risks to the fetus.
Prozac is excreted in breast milk. Therefore, use of Prozac while nursing is not recommended.
Summary
Zoloft (sertraline) and Prozac (fluoxetine) are selective serotonin reuptake inhibitor (SSRI) type antidepressants used to treat depression, obsessive-compulsive disorder (OCD), panic disorder, and premenstrual dysphoric disorder (PMDD). Zoloft is also used to treat post-traumatic stress disorder (PTSD) and social anxiety disorder. Prozac is also used to treat bulimia, and it is also prescribed in combination with olanzapine (Zyprexa) to treat resistant depression and depression associated with bipolar disorder.
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Second Source article from WebMD
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Panic Attacks
Panic attacks are sudden feelings of terror that strike without warning. These episodes can occur at any time, even during sleep. A person experiencing a panic attack may believe that he or she is having a heart attack or that death is imminent. The fear and terror that a person experiences during a panic attack are not in proportion to the true situation and may be unrelated to what is happening around them. Most people with panic attacks experience several of the following symptoms: racing heartbeat, faintness, dizziness, numbness or tingling in the hands and fingers, chills, chest pains, difficulty breathing, and a feeling of loss or control. There are several treatments for panic attacks.
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Depression
Depression is an illness that involves the body, mood, and thoughts and affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. The principal types of depression are major depression, dysthymia, and bipolar disease (also called manic-depressive disease).
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Premenstrual Dysphoric Disorder (PMDD)
Premenstrual dysphoric disorder (PMDD) is considered a severe form of premenstrual syndrome (PMS). PMDD has also been referred to as late luteal phase dysphoric disorder. The cause of PMDD is unknown. Some of the common symptoms of PMDD (not an inclusive list) include mood swings, bloating, fatigue, headache, irritability, headache, breast tenderness, acne, and hot flashes. Treatment for PMDD is with medication to treat the symptoms of PMDD.
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Bipolar Disorder in Children, Teen, and Adults
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Obsessive Compulsive Disorder (OCD)
Obsessive-compulsive disorder (OCD) is an anxiety disorder that causes a person to suffer repeated obsessions and compulsions. Symptoms include irresistible impulses despite a person's realization that the thoughts are irrational, excessive hand washing, skin picking, lock checking, or repeatedly rearranging items. People with OCD are more likely to develop trichotillomania, muscle or vocal tics, or an eating disorder. Treatment for OCD includes psychotherapy, behavioral therapy, and medication.
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Post-traumatic Stress Disorder
Post-traumatic stress disorder (PTSD), a psychiatric condition, can develop after any catastrophic life event. Symptoms include nightmares, flashbacks, sweating, rapid heart rate, detachment, amnesia, sleep problems, irritability, and exaggerated startle response. Treatment may involve psychotherapy, group support, and medication.
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Bulimia
People with bulimia nervosa, an eating disorder that involves episodes of bingeing and purging, experience symptoms and signs such as deteriorating teeth, sore throat, constipation, thinning hair, and dehydration. Treatment of bulimia may involve cognitive behavior therapy, family therapy, nutritional counseling, and medication.
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