Prozac side effects (A complete Guide)


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Page last updated: 15/10/2022

Prozac side effects

In this blog post about Prozac’s side effects, we will also discuss what Prozac is, additional side effects, overdose symptoms and additional recommendations. 

Prozac side effects

Some of the most common and known Prozac side effects according to RxList are:

  • Nausea,
  • Upset stomach,
  • Constipation,
  • Headaches,
  • Anxiety,
  • Sleep problems (insomnia),
  • Drowsiness,
  • Dizziness,
  • Nervousness,
  • Heart palpitations,
  • Loss of appetite or increase in appetite,
  • Weight changes
  • Cold symptoms (stuffy nose, sneezing, sore throat),
  • Dry mouth,
  • Decreased sex drive,
  • Impotence
  • Difficulty having an orgasm

Not just antidepressants, but other medicines used to treat health related issues like Beconase also have side effects.

Prozac: What is it?

Prozac (fluoxetine) belongs to the Selective Serotonin Reuptake Inhibitors (SSRIs) group of antidepressants and it is considered very effective when treating depression.

However, when compared to citalopram, it seems to have a slower reaction time. 

Unlike Citalopram, Prozac is also used when treating other disorders such as bulimia, obsessive-compulsive disorder (OCD), panic disorder and premenstrual dysphoric disorder (PMDD).

Antidepressants are drugs prescribed to treat mental disorders. Some of the most common are:

  • Anxiety disorders
  • Phobias
  • Bulimia
  • Some medical conditions

How do Antidepressants work?

Antidepressants act in your body by prolonging or boosting the activity of neurochemicals such as noradrenaline and serotonin, which are thought to be involved in mood regulation. 

There are several different types of antidepressants, and they are:

  • selective serotonin reuptake inhibitors (SSRIs)
  • serotonin and noradrenaline reuptake inhibitors (SNRIs)
  • tricyclics and tricyclic-related drugs
  • monoamine oxidase inhibitors (MAOIs) 
  • other antidepressants
Prozac side effects (A complete Guide)

How should I take Prozac?

You can take it with or without food. Oral tablets are available at 10 mg, 20 mg or 40 mg.

It is available  in capsules, tablets, capsules with delayed-release and oral solution

Also, it can take 4-6 days for you to start seeing some improvement long term and 1-3 days short term.

Remember, You should always follow your doctor’s instructions at all times.  

Prozac side effects (A complete Guide)

Before taking Prozac 

Before taking Prozac let your doctor know if you have any of the following:

  • Cirrhosis of liver 
  • Kidney disease
  • Diabetes
  • Glaucoma
  • Epilepsy or seizures
  • Bipolar disorder
  • History of drug abuse or suicidal thoughts
  • If you are being treated with electroconvulsive therapy (ECT)

Prozac Dosage

According to the National Institute for Health and Care Excellence (NICE) the dosages are recommended as follows:

Major depression

How: by mouth

Prozac Dosage for Adults:

The initial dose is 20 mg a day. The dose is increased after being assessed 3 to 4 weeks later and intervals thereafter.

The daily dose may be administered as a single or divided dose. The maximum recommended is 60 mg per day.

Prozac Dosage for the Elderly:

Same as in a regular adult dosage, Initially 20 mg daily. The dose is increased after being assessed 3 to 4 weeks later and intervals thereafter.

The daily dose may be administered as a single or divided dose. The maximum recommended dose is 40 mg a day but doses up to 60 mg daily can be used.

Bulimia nervosa

How: by mouth

Dosage for Adults

Recommended: 60 mg a daily and it may be administered as a single or divided dose.

For Elderly

Recommended: Up to 40 mg daily and the daily dose may be administered as a single or divided dose. Usually, the maximum dose a day is 40 mg but doses up to 60 mg daily can be used.

Obsessive-compulsive disorder

How: by mouth

Dosage for Adults

Recommended: 60 mg a daily and it may be administered as a single or divided dose.

Recommended: 20 mg a day, increased if necessary up to 60 mg a day.  The daily dose may be administered as a single or divided dose.

The dose can get increased gradually and if the treatment seems to be inadequate after 10 weeks then the dose gets increased to 60 mg a day.

Attention: these are just referenced dosages from NICE. Don’t stop your medication or change the intake unless your doctor instructs you to. 

Other Prozac side effects 

According to the Mayo Clinic here are some of the common, less common and rare Prozac side effects.

More common Prozac side effects 

  1. Hives, itching, or skin rash
  2. inability to sit still
  3. restlessness

Less common Prozac side effects

  1. Chills or fever
  2. joint or muscle pain

Rare Prozac side effects

  1. Anxiety
  2. cold sweats
  3. confusion
  4. convulsions (seizures)
  5. cool pale skin
  6. diarrhea
  7. difficulty with concentration
  8. drowsiness
  9. dryness of the mouth
  10. excessive hunger
  11. fast or irregular heartbeat
  12. headache
  13. increased sweating
  14. increased thirst
  15. lack of energy
  16. mood or behavior changes
  17. overactive reflexes
  18. purple or red spots on the skin
  19. racing heartbeat
  20. shakiness or an unsteady walk
  21. shivering or shaking
  22. talking, feeling, and acting with excitement and activity you cannot control
  23. trouble with breathing
  24. unusual or incomplete body or facial movements
  25. unusual tiredness or weakness

Prozac Drug interactions

Prozac may interact with medicines meant for cold or allergies, sedatives, narcotics, pain killers, sleeping pills, muscle relaxers, medicine for seizures or anti-anxiety medication, monoamine oxidase inhibitors (MAOIs), nonsteroidal anti-inflammatory drugs (NSAIDs), other antidepressants or medicine for migraine. 

Drugs that can interact with Prozac:

According to Mayo Clinic, here are some of the drugs that can interact with Prozac: 

  • Alprazolam; Clopidrogel; Clozapine; Flecainide; Haloperidol; Nebivolol; Vinblastine, Seizure medications; Abciximab; Abiraterone Acetate; Acecainide; Aceclofenac; Acemetacin; Acenocoumarol; Ajmaline; Alfentanil; Alfuzosin; Almotriptan; Amineptine; Amiodarone; Amisulpride; Amitriptyline; Amitriptylinoxide; Amoxapine; Amphetamine; Amtolmetin Guacil; Anagrelide; Ancrod; Anisindione; Antithrombin III Human; Apixaban; Apomorphine; Aprindine; Ardeparin; Argatroban; Aripiprazole; Aripiprazole Lauroxil; Arsenic Trioxide; Asenapine; Aspirin; Astemizole; Atazanavir

For a complete list of drugs click here.

Prozac Overdose

If you think you or someone else has taken a Prozac overdose you should get in contact with medical emergency services. 

Some of the most common symptoms of a Prozac overdose are:

  • Feeling confused
  • Being unresponsive
  • Shaking uncontrollably
  • Feeling dizzy
  • Irregular or very fast heartbeat
  • Hallucinations
  • Restlessness
  • Having fever
  • Fainting
  • Losing consciousness

Possible complications after an overdose

A Prozac overdose can come with medical complications such as seizures, abnormal heart rhythm, kidney failure and respiratory. 

Remember that it is best to avoid the combination of prozac and alcohol. It can make symptoms worse and, in some cases, can be dangerous.

Benefits of Prozac Dosage

According to some of the benefits of Prozac are described as follows:

  • Prozac may be used in the treatment of depression and it can help maintain the relief of depression in adults and children (8 -18 years).
  • Prozac may be helpful for the relief of the obsessive-compulsive symptoms in adults and children (7-17 yeats).  
  • Prozac may be helpful in the treatment of eating disorders like bulimia nervosa, relieve the symptoms (moderate to severe) such as binge-eating and vomiting.
  • Prozac may be helpful in the treatment of panic disorders in adults (with/without agoraphobia).
  • Prozac may be helpful in treating premenstrual dysphoric disorder or PMDD. 
  • Prozac is less likely to cause weight gain in comparison to other antidepressants, but it can cause insomnia.

Prozac side effects (A complete Guide)

Negative aspects of Prozac side effects

According to some of the negative aspects of Prozac are described as follows:

  • Cab cause anxiety, fatigue or lack of energy, drowsiness or insomnia, diarrhea, indigestion, among others specified as side effects. 
  • As with other antidepressants, taking Prozac increases the chance of suicidal thoughts and behavior.
  • Taking Prozac can cause drowsiness and impair your judgment or affect your driving abilities. 
  • Interaction with other drugs or overdosage can result in serotonin syndrome (includes symptoms such as agitation, hallucinations, coma, and delirium), a higher fast rate, feeling dizzy, flushed, shaky and muscle rigidity. 
  • Another syndrome caused by interaction with other drugs or substances is neuroleptic malignant syndrome. Symptoms for this syndrome include high body temperature, muscle rigidity, and psychological disturbances. 
  • Increases the risk of bleeding, especially if it is used with other drugs that also may increase bleeding. 
  • It can precipitate manic episodes if the person taking Prozac has undiagnosed bipolar disorder.
  •  May cause withdrawal symptoms if medication intake is stopped suddenly. 

Antidepressants: Suicidal Risk

Some studies have shown that taking antidepressants is associated with a higher risk of suicidal behavior (suicidal thinking or attempts) when compared to placebo drugs.

This risk has been associated with age in the case in children, adolescents, and adults with major depressive disorder (MDD) or related psychiatric disorders. 

One study conducted by the Centre for Suicide Research in Oxford, England attempted to identify which antidepressant drugs were more closely related to suicides or suicide attempts using coroner reports and hospital admissions from six hospitals across the United Kingdom and Wales (between 2000 and 2006). 

They found that Tricyclic antidepressants or TCAs had the highest toxicity and rate of fatality compared to other classes of antidepressants.

Additionally from the SSRIs group, Citalopram indicated to be the one with the highest toxicity and fatality rates. 

Besides being a treatment often used for depression, it can also be prescribed for the treatment of other major psychiatric disorders such as Obsessive-compulsive disorder (ODD), Panic disorder, premenstrual dysphoric syndrome (PMDD), anxiety disorders, post-traumatic stress disorder (PTSD) and eating disorders. 

People under antidepressant medication should always be monitored and observed closely to help reduce or prevent suicidal behavior.  

Why is this blog post about Prozac side effects important?

If you are considering taking Prozac for depression, obsessive-compulsive disorder, bulimia nervosa, premenstrual dysphoric disorder or panic disorder,  it is important to be aware of any side effects and warning signs of a major medical complication that can be manifested. 

Additionally, it is important to follow the instructions provided by your doctor on how to take the medication correctly and inform immediately if there are complications.

Although we consider this guide compiled accurate and up to date information from trustworthy medical sources, it is not intended as a strict how-to guide, it is only informative.

Additional questions or concerns should be answered by your doctor.

Feel free to comment on the content of “Prozac side effects” in the comments section below.

Frequently Asked Questions (FAQ’s) about Prozac side effects

What is the most common side effect of Prozac?

The most common side effects of Prozac include sweating, trouble sleeping, dizziness, anxiety, nausea, drowsiness, tiredness and frequent yawning may occur. 

Do Prozac side effects go away?

Yes, they usually take 4 to 6 weeks.

The side effects are usually mild and will go away after a couple of weeks but they persist or become worse you should inform your doctor.

Does Prozac cause weight gain?

Prozac can cause weight gain as a side effect, common to antidepressant medication.

Researchers have found that up to 25% of antidepressant users experience weight gain but this could be due to an increased appetite after treating depression symptoms.

How quickly does Prozac work for anxiety?

You will start noticing an improvement in the first 1-2 weeks for anxiety treatment. 

Does Prozac cause hair loss?

Prozac (and other antidepressants), can cause hair loss within the first 3 months of the treatment.

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Mayo Clinic

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