Prozac (Fluoxetine)

(℞) Prescription Required - Fluoxetine is the Generic Equivalent of Prozac

    Prozac (Fluoxetine) Dosage and Side Effects

    PROZAC has been prescribed by your doctor to relieve your symptoms of:

    • Depression (feeling sad, a change in appetite or weight, difficulty concentrating or sleeping, feeling tired, headaches, unexplained aches and pain)
    • Bulimia (eating disorder, characterized by self-induced vomiting after eating)
    • Obsessive-compulsive disorder (recurrent and intrusive thought, feeling, idea, or sensation; recurrent pattern of behaviour, or unwanted thoughts or actions)

    Warnings and Precautions

    During treatment with these types of medications, it is important that you and your doctor have good ongoing communication about how you are feeling.

    PROZAC is not for use in children under 18 years of age.

    New or Worsened Emotional or Behavioural Problems:

    Particularly in the first few weeks or when doses are adjusted, a small number of patients taking drugs of this type may feel worse instead of better. They may experience new or worsened feelings of agitation, hostility, anxiety, impulsivity, or thoughts about suicide, self-harm or harm to others. Suicidal thoughts and actions can occur in any age group but may be more likely in patients 18 to 24 years old. Should this happen to you or those in your care, consult your doctor immediately. Close observation by a doctor is necessary in this situation. Do not discontinue your medication on your own.

    You may be more likely to think like this if you have previously had thoughts about harming yourself.

    You may find it helpful to tell a relative or close friend that you are depressed or have an anxiety disorder, and ask them to read this leaflet. You might ask them to tell you if they think your depression or anxiety is getting worse, or if they are worried about changes in your behaviour.

    PROZAC has an effect on the electrical activity of the heart:

    In very rare cases, this effect can lead to disturbances in heart rhythm. These heart rhythm disturbances are more likely in patients with risk factors, such as heart disease, or in the presence of certain drugs. In general, females and people more than 65 years in age are at higher risk. It is important to follow the instructions of your doctor with regard to dosing. If you experience any symptoms of a possible heart rhythm disturbance, such as dizziness, palpitations (sensation of rapid, pounding, or irregular heartbeat), fainting, or seizures, you should seek immediate medical attention.

    Before starting PROZAC, tell your doctor or pharmacist:

    • if you have ever had an allergic reaction to any medication
    • if you have QT/QTc prolongation or a family history of QT/QTc prolongation
    • if you have a heart disease
    • if you have a personal history of fainting spells
    • if you have a family history of sudden cardiac death at <50 years
    • if you have electrolyte disturbances (e.g., low blood potassium or magnesium levels) or conditions that could lead to electrolyte disturbances (e.g., vomiting, diarrhea, dehydration)
    • if you use diuretics, enemas and/or laxatives
    • all your medical conditions, including a history of liver or kidney problems, seizures or blackouts, diabetes, bleeding disorder or have been told that you have low platelets
    • if you had a recent bone fracture or were told you have osteoporosis or risk factors for osteoporosis
    • any medications (prescription or nonprescription) you are taking or have recently taken, especially monoamine oxidase (MAO) inhibitors (e.g., phenelzine sulfate, tranylcypromine sulfate, moclobemide or selegeline) or thioridazine, or anticoagulants, acetylsalicylic acid (e.g., Aspirin) and other non-steroidal anti-inflammatory drugs (e.g., ibuprofen)
    • if you are taking tamoxifen (used to treat breast cancer)
    • any natural or herbal products you are taking (e.g. St. John's Wort)
    • if you are pregnant or thinking about becoming pregnant, or if you are breast feeding
    • your habits of alcohol and/or street drug consumption
    • if you drive a vehicle or perform hazardous tasks during your work

    Angle-closure Glaucoma:

    PROZAC can cause an acute attack of glaucoma. Having your eyes examined before you take PROZAC could help identify if you are at risk of having angle-closure glaucoma. Seek immediate medical attention if you experience:

    • eye pain
    • changes in vision
    • swelling or redness in or around the eye.

    Effects on Pregnancy and Newborns:

    If you are already taking PROZAC and have just found out that you are pregnant, you should talk to your doctor as soon as possible.

    Taking PROZAC in early stages of pregnancy:

    Some studies have suggested a small increased risk of birth defects affecting the heart in babies whose mothers took PROZAC during the first few months of pregnancy. In the general population, about 1 in 100 babies are born with a heart defect. The studies found that this increased to about 2 in 100 babies whose mothers took PROZAC during early pregnancy.

    Taking PROZAC in later stages of pregnancy:

    Possible complications at birth (from taking any newer antidepressant, including PROZAC):

    Post-marketing reports indicate that some newborns whose mothers took an SSRI (selective serotonin reuptake inhibitor) or other newer antidepressant during pregnancy have developed complications at birth requiring prolonged hospitalization, breathing support and tube feeding. Reported symptoms included feeding and/or breathing difficulties, seizures, tense or overly relaxed muscles, jitteriness and constant crying.

    In most cases, the newer antidepressant was taken during the third trimester of pregnancy. These symptoms are consistent with either a direct adverse effect of the antidepressant on the baby, or possibly a discontinuation syndrome caused by sudden withdrawal from the drug. These symptoms normally resolve over time. However, if your baby experiences any of these symptoms, contact your doctor as soon as you can.

    Persistent Pulmonary Hypertension (PPHN) and newer antidepressants:

    The use of SSRIs, including PROZAC, during late pregnancy, may increase the risk of a serious lung condition called persistent pulmonary hypertension of the newborn (PPHN) that causes breathing difficulties in newborns soon after birth. In the general population, PPHN is known to occur in about 1 or 2 per 1000 newborns but this may be increased 2 to 6 times in babies whose mothers used SSRIs during late pregnancy.

    If you are pregnant and taking an SSRI, or other newer antidepressant, you should discuss the risks and benefits of the various treatment options with your doctor. It is very important that you do NOT stop taking these medications without first consulting your doctor.

    Taking PROZAC may increase your risk of breaking a bone if you are elderly or have osteoporosis or have other major risk factors for breaking a bone. You should take extra care to avoid falls especially if you get dizzy or have low blood pressure.

    Side Effects

    Like other medications, PROZAC can cause some side effects. You may not experience any of them. For most patients, side effects are likely to be minor and temporary. However, some may be serious. Some of these side effects may be dose related. Consult your doctor if you experience these or other side effects, as the dose may have to be adjusted.

    The most common side effects of PROZAC are:

    • nausea
    • dizziness
    • headache
    • anxiety
    • nervousness
    • drowsiness
    • insomnia (difficulty falling or staying asleep)
    • fatigue
    • weakness
    • diarrhea
    • upset stomach
    • dry mouth
    • loss of appetite
    • excessive sweating

    PROZAC does not usually affect people's normal activities. However, some people feel sleepy while taking it, in which case they should not drive or operate machinery.

    Although psychiatric disorders may be associated with decreases in sexual desire, performance and satisfaction, treatment with this medication may also affect sexual functioning. Occasionally, these symptoms may continue after stopping PROZAC.

    PROZAC can raise your levels of a hormone called “prolactin” (measured with a blood test). Symptoms of high prolactin may include:

    In men: breast swelling, difficulty in getting or maintaining erections, or other sexual dysfunction.

    In women: breast discomfort, leakage of milk from the breasts, missed menstrual periods, or other problems with your cycle.

    If you experience any symptoms of a possible heart rhythm disturbance, such as dizziness, palpitations, fainting or seizures, you should seek immediate medical attention.

    Discontinuation Symptoms:

    Contact your doctor before stopping or reducing your dosage of PROZAC. Symptoms such as headache, insomnia, paresthesias (numbness, tingling, burning, or prickling sensation) nervousness, anxiety, nausea, sweating, dizziness, jitteriness and weakness and other symptoms have been reported after stopping PROZAC. These symptoms usually disappear without needing treatment. Tell your doctor immediately if you have these or any other symptoms. Your doctor may adjust the dosage of PROZAC to alleviate the symptoms.

    Effects on Newborns:

    Some newborns whose mothers took an SSRI (Selective Serotonin Uptake Inhibitor) or other newer antidepressants during pregnancy have shown such symptoms as breathing and feeding difficulties, jitteriness and constant crying. If your baby experiences any of these symptoms, contact your doctor as soon as you can.

    Interactions with this medication

    Serious Drug Interactions

    Do not use PROZAC if you are taking or have recently taken:

    • Monoamine oxidase inhibitor (e.g., phenelzine, tranylcypromine, moclobemide or selegiline, linezolid, methylene blue)
    • Thioridazine

    You should tell your doctor if you are taking or have recently taken any medications (prescription, nonprescription or natural/herbal), especially:

    • other antidepressants, such as SSRIs, certain tricyclics, drugs used to treat schizophrenia, or bipolar depression (e.g. lithium)
    • anti-infectives
    • cancer drugs
    • asthma drugs
    • drugs to treat nausea and vomiting
    • painkillers
    • diuretics
    • certain medicines which may affect blood clotting and increase bleeding, such as oral anticoagulants (e.g., warfarin, dabigatran), acetylsalicylic acid (e.g. Aspirin) and other non-steroidal anti-inflammatory drugs (e.g. ibuprofen)
    • tamoxifen, which is used to treat breast cancer
    • certain medicines used to treat patients with irregular heart beats (antiarrhythmics)
    • certain drugs used to treat diabetes
    • other drugs that affect serotonin, such as lithium, linezolid, drugs containing tryptophan, St. John's Wort, triptans used to treat migraines
    • certain medicines used to treat pain, such as fentanyl (used in anaesthesia or to treat chronic pain), tramadol, tapentadol, meperidine, methadone, pentazocine
    • certain medicines used to treat cough, such as dextromethorphan
    • sedatives such as benzodiazepines

    As with many drugs that work directly on the brain, use of alcohol while taking PROZAC should be limited/moderate.

    Proper Use of this medication

    • It is very important that you take PROZAC exactly as your doctor has instructed.
    • PROZAC is usually taken once a day. It may be taken with or without food. If you are taking capsules, you should swallow the capsules whole; do not chew them.
    • You should continue to take your medicine even if you do not feel better, as it may take a number of weeks for your medicine to work.
    • Keep taking your PROZAC until the doctor tells you to stop.
    • Talk to your doctor before you stop taking your medication on your own.

    Remember: This medicine has been prescribed only for you. Do not give it to anybody else, as they may experience undesirable effects, which may be serious.

    Usual adult dose:


    Usual initial dose: 20 mg a day in the morning.

    Maximum dose: 60 mg a day.


    Recommended dose: 60 mg a day.

    Obsessive-Compulsive Disorder:

    Dose range: 20 to 60 mg a day.


    In case of drug overdose, contact a health care practitioner, hospital emergency department or regional Poison Control Centre immediately, even if there are no symptoms.

    Missed dose:

    If you forget to take a dose of PROZAC, take it as soon as you remember. Take your next dose at the next scheduled time; do not try to make up for a missed dose by taking a double dose the next time.

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    The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.