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Prozac Side Effects Center
Pharmacy Editor: Omudhome Ogbru, PharmD
Prozac (fluoxetine) is an oral drug used for treating depression, bulimia, obsessive-compulsive disorder (OCD), panic disorder, and premenstrual dysphoric disorder (PMDD). It is in a class of drugs called selective serotonin reuptake inhibitors (SSRIs). A generic formulation is available. Prozac may cause nausea, headaches, anxiety, insomnia, drowsiness, and loss of appetite. Some patients may experience withdrawal reactions such nausea, nervousness, and insomnia upon stopping Prozac.
The recommended dose of Prozac is 10-80 mg daily. Prozac should not be taken with monoamine oxidase inhibitors (MAOI) (for example, isocarboxazid [Marplan)]. Prozac should not be administered for at least 14 days after stopping and MAOIs should not be administered for at least 5 weeks after Prozac has been stopped. Use of Prozac during the third trimester of pregnancy may lead to adverse effects in the newborn. Prozac is excreted in breast milk.
Our Prozac Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
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 is Patient Information in Detail?
Easy-to-read and understand detailed drug information and pill images for the patient or caregiver from Cerner Multum.
Prozac in Detail - Patient Information: Side Effects
Get emergency medical help if you have any of these signs of an allergic reaction: 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 any of these serious side effects:
- severe blistering, peeling, and red skin rash;
- very stiff (rigid) muscles, high fever, sweating, fast or uneven heartbeats, tremors, overactive reflexes;
- nausea, vomiting, diarrhea, loss of appetite, feeling unsteady, loss of coordination; or
- headache, trouble concentrating, memory problems, weakness, confusion, hallucinations, fainting, seizure, shallow breathing or breathing that stops.
Less serious side effects may include:
- cold symptoms such as stuffy nose, sneezing, sore throat;
- drowsiness, dizziness, feeling nervous;
- mild nausea, upset stomach, constipation;
- increased appetite, weight changes;
- sleep problems (insomnia);
- decreased sex drive, impotence, or difficulty having an orgasm; or
- dry mouth.
Read the entire detailed patient monograph for Prozac (Fluoxetine Hcl) »
What is Patient Information Overview?
A concise overview of the drug for the patient or caregiver from First DataBank.
Prozac Overview - Patient Information: Side Effects
Nausea, drowsiness, dizziness, anxiety, trouble sleeping, loss of appetite, tiredness, sweating, or yawning may occur. If any of these effects persist or worsen, tell your doctor promptly.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if any of these unlikely but serious side effects occur: unusual or severe mental/mood changes (such as agitation, unusual high energy/excitement, thoughts of suicide), easy bruising/bleeding, muscle weakness/spasm, shakiness (tremor), decreased interest in sex, changes in sexual ability, unusual weight loss, large pupils.
Get medical help right away if any of these rare but serious side effects occur: bloody/black/tarry stools, vomit that looks like coffee grounds, seizures, change in amount of urine.
If you have diabetes, fluoxetine may affect your blood sugar levels. Monitor your blood sugar regularly and share the results with your doctor. Your doctor may need to adjust your medication, diet, and exercise when you start or stop fluoxetine.
This medication may rarely cause a very serious condition called serotonin syndrome. The risk increases when this medication is used with certain other drugs (see Drug Interactions section). Get medical help right away if you develop some of the following symptoms: hallucinations, unusual restlessness, loss of coordination, fast heartbeat, severe dizziness, unexplained fever, severe nausea/vomiting/diarrhea, twitchy muscles.
Rarely, males may have a painful or prolonged erection lasting 4 or more hours. If this occurs, stop using this drug and get medical help right away, or permanent problems could occur.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Read the entire patient information overview for Prozac (Fluoxetine Hcl)»
What is Prescribing information?
The FDA package insert formatted in easy-to-find categories for health professionals and clinicians.
Prozac FDA Prescribing Information: Side Effects
When using PROZAC and olanzapine in combination, also refer to the Adverse Reactions section of the package insert for Symbyax.
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect or predict the rates observed in practice.
Multiple doses of PROZAC have been administered to 10,782 patients with various diagnoses in US clinical trials. In addition, there have been 425 patients administered PROZAC in panic clinical trials. Adverse reactions were recorded by clinical investigators using descriptive terminology of their own choosing. Consequently, it is not possible to provide a meaningful estimate of the proportion of individuals experiencing adverse reactions without first grouping similar types of reactions into a limited (i.e., reduced) number of standardized reaction categories.
In the tables and tabulations that follow, COSTART Dictionary terminology has been used to classify reported adverse reactions. The stated frequencies represent the proportion of individuals who experienced, at least once, a treatment-emergent adverse reaction of the type listed. A reaction was considered treatment-emergent if it occurred for the first time or worsened while receiving therapy following baseline evaluation. It is important to emphasize that reactions reported during therapy were not necessarily caused by it.
The prescriber should be aware that the figures in the tables and tabulations cannot be used to predict the incidence of side effects in the course of usual medical practice where patient characteristics and other factors differ from those that prevailed in the clinical trials. Similarly, the cited frequencies cannot be compared with figures obtained from other clinical investigations involving different treatments, uses, and investigators. The cited figures, however, do provide the prescribing physician with some basis for estimating the relative contribution of drug and nondrug factors to the side effect incidence rate in the population studied.
Incidence in Major Depressive Disorder, OCD, bulimia, and panic disorder placebo-controlled clinical trials (excluding data from extensions of trials) - Table 3 enumerates the most common treatment-emergent adverse reactions associated with the use of PROZAC (incidence of at least 5% for PROZAC and at least twice that for placebo within at least 1 of the indications) for the treatment of Major Depressive Disorder, OCD, and bulimia in US controlled clinical trials and Panic Disorder in US plus non-US controlled trials. Table 5 enumerates treatment-emergent adverse reactions that occurred in 2% or more patients treated with PROZAC and with incidence greater than placebo who participated in US Major Depressive Disorder, OCD, and bulimia controlled clinical trials and US plus non-US Panic Disorder controlled clinical trials. Table 4 provides combined data for the pool of studies that are provided separately by indication in Table 3.
Table 3: Most Common Treatment-Emergent Adverse
Reactions: Incidence in Major Depressive Disorder, OCD, Bulimia, and Panic
Disorder Placebo-Controlled Clinical Trials1,2
|Body System/ Adverse Reaction||Percentage of Patients Reporting Event|
|Major Depressive Disorder||OCD||Bulimia||Panic Disorder|
|Body as a Whole|
|Skin and Appendages|
|1 Incidence less than 1%.
2 Includes US data for Major Depressive Disorder, OCD, Bulimia, and Panic Disorder clinical trials, plus non-US data for Panic Disorder clinical trials.
3 Denominator used was for males only (N=690 PROZAC Major Depressive Disorder; N=410 placebo Major Depressive Disorder; N=116 PROZAC OCD; N=43 placebo OCD; N=14 PROZAC bulimia; N=1 placebo bulimia; N=162 PROZAC panic; N=121 placebo panic).
Table 4: Treatment-Emergent Adverse Reactions:
Incidence in Major Depressive Disorder, OCD, Bulimia, and Panic Disorder
Placebo-Controlled Clinical Trials1,2
|Body System/Adverse Reaction||Percentage of Patients Reporting Event|
|Major Depressive Disorder, OCD, Bulimia, and Panic Disorder Combined|
|Body as a Whole|
|Metabolic and Nutritional Disorders|
|Skin and Appendages|
|1 Incidence less than 1%.
2 Includes US data for Major Depressive Disorder, OCD, bulimia, and Panic Disorder clinical trials, plus non-US data for Panic Disorder clinical trials.
Associated with discontinuation in Major Depressive Disorder, OCD, bulimia, and Panic Disorder placebo-controlled clinical trials (excluding data from extensions of trials) - Table 5 lists the adverse reactions associated with discontinuation of PROZAC treatment (incidence at least twice that for placebo and at least 1% for PROZAC in clinical trials collecting only a primary reaction associated with discontinuation) in Major Depressive Disorder, OCD, bulimia, and Panic Disorder clinical trials, plus non-US Panic Disorder clinical trials.
Table 5: Most Common Adverse Reactions Associated with
Discontinuation in Major Depressive Disorder, OCD, Bulimia, and Panic Disorder
Placebo-Controlled Clinical Trials1
|Major Depressive Disorder, OCD, Bulimia, and Panic Disorder Combined
|Major Depressive Disorder
|Anxiety (1%)||--||Anxiety (2%)||--||Anxiety (2%)|
|--||Nervousness (1%)||--||--||Nervousness (1%)|
|1 Includes US Major Depressive Disorder, OCD, bulimia, and Panic Disorder clinical trials, plus non-US Panic Disorder clinical trials.|
Other adverse reactions in pediatric patients (children and adolescents) - Treatment-emergent adverse reactions were collected in 322 pediatric patients (180 fluoxetine-treated, 142 placebo-treated). The overall profile of adverse reactions was generally similar to that seen in adult studies, as shown in Tables 4 and 5. However, the following adverse reactions (excluding those which appear in the body or footnotes of Tables 4 and 5 and those for which the COSTART terms were uninformative or misleading) were reported at an incidence of at least 2% for fluoxetine and greater than placebo: thirst, hyperkinesia, agitation, personality disorder, epistaxis, urinary frequency, and menorrhagia.
The most common adverse reaction (incidence at least 1% for fluoxetine and greater than placebo) associated with discontinuation in 3 pediatric placebo-controlled trials (N=418 randomized; 228 fluoxetine-treated; 190 placebo-treated) was mania/hypomania (1.8% for fluoxetine-treated, 0% for placebo-treated). In these clinical trials, only a primary reaction associated with discontinuation was collected.
Reactions observed in PROZAC Weekly clinical trials - Treatment-emergent adverse reactions in clinical trials with PROZAC Weekly were similar to the adverse reactions reported by patients in clinical trials with PROZAC daily. In a placebo-controlled clinical trial, more patients taking PROZAC Weekly reported diarrhea than patients taking placebo (10% versus 3%, respectively) or taking PROZAC 20 mg daily (10% versus 5%, respectively).
Male and female sexual dysfunction with SSRIs - Although changes in sexual desire, sexual performance, and sexual satisfaction often occur as manifestations of a psychiatric disorder, they may also be a consequence of pharmacologic treatment. In particular, some evidence suggests that SSRIs can cause such untoward sexual experiences. Reliable estimates of the incidence and severity of untoward experiences involving sexual desire, performance, and satisfaction are difficult to obtain, however, in part because patients and physicians may be reluctant to discuss them. Accordingly, estimates of the incidence of untoward sexual experience and performance, cited in product labeling, are likely to underestimate their actual incidence. In patients enrolled in US Major Depressive Disorder, OCD, and bulimia placebo-controlled clinical trials, decreased libido was the only sexual side effect reported by at least 2% of patients taking fluoxetine (4% fluoxetine, < 1% placebo). There have been spontaneous reports in women taking fluoxetine of orgasmic dysfunction, including anorgasmia.
There are no adequate and well-controlled studies examining sexual dysfunction with fluoxetine treatment.
Symptoms of sexual dysfunction occasionally persist after discontinuation of fluoxetine treatment.
Priapism has been reported with all SSRIs.
While it is difficult to know the precise risk of sexual dysfunction associated with the use of SSRIs, physicians should routinely inquire about such possible side effects.
Following is a list of treatment-emergent adverse reactions reported by patients treated with fluoxetine in clinical trials. This listing is not intended to include reactions (1) already listed in previous tables or elsewhere in labeling, (2) for which a drug cause was remote, (3) which were so general as to be uninformative, (4) which were not considered to have significant clinical implications, or (5) which occurred at a rate equal to or less than placebo.
Reactions are classified by body system using the following definitions: frequent adverse reactions are those occurring in at least 1/100 patients; infrequent adverse reactions are those occurring in 1/100 to 1/1000 patients; rare reactions are those occurring in fewer than 1/1000 patients.
Body as a Whole - Frequent: chills; Infrequent: suicide attempt; Rare: acute abdominal syndrome, photosensitivity reaction.
Digestive System - Infrequent: dysphagia, gastritis, gastroenteritis, melena, stomach ulcer; Rare: bloody diarrhea, duodenal ulcer, esophageal ulcer, gastrointestinal hemorrhage, hematemesis, hepatitis, peptic ulcer, stomach ulcer hemorrhage.
Nervous System - Frequent: emotional lability; Infrequent: akathisia, ataxia, balance disorder1, bruxism1, buccoglossal syndrome, depersonalization, euphoria, hypertonia, libido increased, myoclonus, paranoid reaction; Rare: delusions.
Respiratory System - Rare: larynx edema.
Skin and Appendages - Infrequent: alopecia; Rare: purpuric rash.
Special Senses - Frequent: taste perversion; Infrequent: mydriasis.
1 MedDRA dictionary term from integrated
database of placebo controlled trials of 15870 patients, of which 9673 patients
2 Group term that includes individual MedDRA terms: cervix hemorrhage uterine, dysfunctional uterine bleeding, genital hemorrhage, menometrorrhagia, menorrhagia, metrorrhagia, polymenorrhea, postmenopausal hemorrhage, uterine hemorrhage, vaginal hemorrhage. Adjusted for gender.
The following adverse reactions have been identified during post approval use of PROZAC. Because these reactions are reported voluntarily from a population of uncertain size, it is difficult to reliably estimate their frequency or evaluate a causal relationship to drug exposure.
Voluntary reports of adverse reactions temporally associated with PROZAC that have been received since market introduction and that may have no causal relationship with the drug include the following: aplastic anemia, atrial fibrillation, cataract, cerebrovascular accident1, cholestatic jaundice, dyskinesia (including, for example, a case of buccal-lingual-masticatory syndrome with involuntary tongue protrusion reported to develop in a 77-year-old female after 5 weeks of fluoxetine therapy and which completely resolved over the next few months following drug discontinuation), eosinophilic pneumonia1, epidermal necrolysis, erythema multiforme, erythema nodosum, exfoliative dermatitis, gynecomastia, heart arrest1, hepatic failure/necrosis, hyperprolactinemia, hypoglycemia, immune-related hemolytic anemia, kidney failure, memory impairment, movement disorders developing in patients with risk factors including drugs associated with such reactions and worsening of pre-existing movement disorders, optic neuritis, pancreatitis1, pancytopenia, pulmonary embolism, pulmonary hypertension, QT prolongation, Stevens-Johnson syndrome, thrombocytopenia1, thrombocytopenic purpura, ventricular tachycardia (including torsades de pointes-type arrhythmias), vaginal bleeding, and violent behaviors1.
1 These terms represent serious adverse events, but do not meet the definition for adverse drug reactions. They are included here because of their seriousness.
Read the entire FDA prescribing information for Prozac (Fluoxetine Hcl) »
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