INN monograph
Fluoxetine
Therapeutic agent (verify pharmacological class) · POM
Source-linked · Updated 03 Aug 2026 · Source: Local active-ingredient clinical extract; FDA drug label via OpenFDA/DailyMed; Professional class pharmacology (Therapeutic agent (verify pharmacological class))
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Contraindications
- combination, also refer to the Contraindications section of the package insert for Symbyax.
- Serotonin Syndrome and MAOIs: Do not use MAOIs intended to treat psychiatric disorders with fluoxetine or within 5 weeks of stopping treatment with fluoxetine.
- Do not use fluoxetine within 14 days of stopping an MAOI intended to treat psychiatric disorders.
- In addition, do not start fluoxetine in a patient who is being treated with linezolid or intravenous methylene blue ( 4.1 ) Pimozide: Do not use.
- Risk of QT prolongation and drug interaction ( 4.2 , 5.11 , 7.7 , 7.8 ) Thioridazine: Do not use.
- Risk of QT interval prolongation and elevated thioridazine plasma levels.
- Do not use thioridazine within 5 weeks of discontinuing fluoxetine.
- Do not use thioridazine within 5 weeks of discontinuing fluoxetine ( 4.2 , 5.11 , 7.7 , 7.8 ) When using fluoxetine and olanzapine in combination, also refer to the Contraindications section of the package insert for Symbyax ( 4 ) 4.1 Monoamine Oxidase Inhibitors (MAOIs) The use of MAOIs intended to treat psychiatric disorders with fluoxetine or within 5 weeks of stopping treatment with fluoxetine is contraindicated because of an increased risk of serotonin syndrome.
- The use of fluoxetine within 14 days of stopping an MAOI intended to treat psychiatric disorders is also contraindicated [see Dosage and Administration (2.9) and Warnings and Precautions (5.2) ].
- Starting fluoxetine in a patient who is being treated with MAOIs such as linezolid or intravenous methylene blue is also contraindicated because of an increased risk of serotonin syndrome [see Dosage and Administration (2.10) and Warnings and Precautions (5.2) ]. 4.2 Other Contraindications The use of fluoxetine is contraindicated with the following: Pimozide [see Warnings and Precautions (5.11) and Drug Interactions (7.7 , 7.8) ] Thioridazine [see Warnings and Precautions (5.11) and Drug Interactions (7.7 , 7.8) ] Pimozide and thioridazine prolong the QT interval.
- Fluoxetine can increase the levels of pimozide and thioridazine through inhibition of CYP2D6.
- Fluoxetine can also prolong the QT interval.
Precautions
- combination, also refer to the Warnings and Precautions section of the package insert for Symbyax.
- Suicidal thoughts and Behaviors in Children, Adolescents, and Young Adults: Monitor for clinical worsening and suicidal thinking and behavior ( 5.1 ) Serotonin Syndrome: Serotonin syndrome has been reported with SSRIs and SNRIs, including fluoxetine , both when taken alone, but especially when co-administered with other serotonergic agents (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, buspirone, amphetamines, and St.
- John's Wort).
- If such symptoms occur, discontinue fluoxetine and initiate supportive treatment.
- If concomitant use of fluoxetine with other serotonergic drugs is clinically warranted, patients should be made aware of a potential increased risk for serotonin syndrome, particularly during treatment initiation and dose increases.
- ( 5.2 ) Serotonin Syndrome: Serotonin syndrome has been reported with SSRIs and SNRIs, including fluoxetine , both when taken alone, but especially when co-administered with other serotonergic agents (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, buspirone, amphetamines, and St.
- John's Wort).
- If such symptoms occur, discontinue fluoxetine and initiate supportive treatment.
- If concomitant use of fluoxetine with other serotonergic drugs is clinically warranted, patients should be made aware of a potential increased risk for serotonin syndrome, particularly during treatment initiation and dose increases.
- ( 5.2 ) Allergic Reactions and Rash: Discontinue upon appearance of rash or allergic phenomena ( 5.3 ) Activation of Mania/Hypomania: Screen for Bipolar Disorder and monitor for mania/hypomania ( 5.4 ) Seizures: Use cautiously in patients with a history of seizures or with conditions that potentially lower the seizure threshold ( 5.5 ) Altered Appetite and Weight: Significant weight loss has occurred ( 5.6 ) Abnormal Bleeding: May increase the risk of bleeding.
- Use with NSAIDs, aspirin, warfarin, or other drugs that affect coagulation may potentiate the risk of gastrointestinal or other bleeding ( 5.7 ) Angle-Closure Glaucoma: Angle-closure glaucoma has occurred in patients with untreated anatomically narrow angles treated with antidepressants.
- ( 5.8 ) Hyponatremia: Has been reported with fluoxetine in association with syndrome of inappropriate antidiuretic hormone (SIADH).
Point of care
Dosing
Adult
( 2.1 ) 20 mg/day in am (initial dose) 10 to 20 mg/day (initial dose) OCD ( 2.2 ) 20 mg/day in am (initial dose) 10 mg/day (initial dose) Bulimia Nervosa ( 2.3 ) 60 mg/day in am Panic Disorder ( 2.4 ) 10 mg/day (initial dose) Depressive Episodes Associated with Bipolar I Disorder ( 2.5 ) Oral in combination with olanzapine: 5 mg of oral olanzapine and 20 mg of fluoxetine once daily (initial dose) Oral in combination with olanzapine: 2.5 mg of oral olanzapine and 20 mg of fluoxetine once daily (initial dose) A lower or less frequent dosage should be used in patients with hepatic impairment, the elderly, and for patients with concurrent disease or on multiple concomitant medications ( 2.7 ) Fluoxetine capsules and olanzapine in combination: Dosage adjustments should be made with the individual components according to efficacy and tolerability ( 2.5 ) Fluoxetine monotherapy is not indicated for the treatment of Depressive Episodes associated with Bipolar I Disorder ( 2.5 ) Safety of the coadministration of doses above 18 mg olanzapine with 75 mg fluoxetine has not been evaluated in adults. ( 2.5 ) Safety of the coadministration of doses above 12 mg olanzapine with 50 mg fluoxetine has not been evaluated in children and adolescents ages 10 to 17 ( 2.5 ) 2.1 Major Depressive Disorder Initial Treatment Adult — Initiate fluoxetine 20 mg/day orally in the morning. Consider a dose increase after several weeks if insufficient clinical improvement is observed. Administer doses above 20 mg/day once daily in the morning or twice daily (i.e., morning and noon). The maximum fluoxetine dose should not exceed 80 mg/day. In controlled trials used to support the efficacy of fluoxetine, patients were administered morning doses ranging from 20 to 80 mg/day. Studies comparing fluoxetine 20, 40, and 60 mg/day to placebo indicate that 20 mg/day is sufficient to obtain a satisfactory response in Major Depressive Disorder in most cases [see Clinical Studies (14.1) ] . Pediatric (children and adolescents) — Initiate Fluoxetine 10 or 20 mg/day. After 1 week at 10 mg/day, increase the dose to 20 mg/day. However, due to higher plasma levels in lower weight children, the starting and target dose in this group may be 10 mg/day. Consider a dose increase to 20 mg/day after several weeks if insufficient clinical improvement is observed. In the short-term (8 to 9 week) controlled clinical trials of fluoxetine supporting its effectiveness in the treatment of Major Depressive Disorder, patients were administered fluoxetine doses of 10 to 20 mg/day [see Clinical Studies (14.1) ] . All patients — As with other drugs effective in the treatment of Major Depressive Disorder, the full effect may be delayed until 4 weeks of treatment or longer. Periodically reassess to determine the need for maintenance treatment. Switching Patients to a Tricyclic Antidepressant (TCA) — Dosage of a TCA may need to be reduced, and plasma TCA concentrations may need to be monitored temporarily when fluoxetine is coadministered or has been recently discontinued [see Warnings and Precautions (5.2) and Drug Interactions (7.7) ] . 2.2 Obsessive Compulsive Disorder Initial Treatment Adult — Initiate fluoxetine 20 mg/day, orally in the morning. Consider a dose increase after several weeks if insufficient clinical improvement is observed. The full therapeutic effect may be delayed until 5 weeks of treatment or longer. Administer doses above 20 mg/day once daily in the morning or twice daily (i.e., morning and noon). A dose range of 20 to 60 mg/day is recommended; however, doses of up to 80 mg/day have been well tolerated in open studies of OCD. The maximum fluoxetine dose should not exceed 80 mg/day. In the controlled clinical trials of fluoxetine supporting its effectiveness in the treatment of OCD, patients were administered fixed daily doses of 20, 40, or 60 mg of fluoxetine or placebo [see Clinical Studies (14.2) ] . In one of these studies, no dose-response relationship for effectiveness was demonstrated. Pediatric (children and adolescents) — In adolescents and higher weight children, initiate treatment with a dose of 10 mg/day. After 2 weeks, increase the dose to 20 mg/day. Consider additional dose increases after several more weeks if insufficient clinical improvement is observed. A dose range of 20 to 60 mg/day is recommended. In lower weight children, initiate treatment with a dose of 10 mg/day. Consider additional dose increases after several more weeks if insufficient clinical improvement is observed. A dose range of 20 to 30 mg/day is recommended. Experience with daily doses greater than 20 mg is very minimal, and there is no experience with doses greater than 60 mg. In the controlled clinical trial of fluoxetine supporting its effectiveness in the treatment of OCD, patients were administered fluoxetine doses in the range of 10 to 60 mg/day [see Clinical Studies (14.2) ] . Periodically reassess to determine the need for treatment. 2.3 Bulimia Nervosa Initial Treatment — Administer fluoxetine 60 mg/day in the morning. For some patients it may be advisable to titrate up to this target dose over several days. Fluoxetine doses above 60 mg/day have not been systematically studied in patients with bulimia. In the controlled clinical trials of fluoxetine supporting its effectiveness in the treatment of Bulimia Nervosa, patients were administered fixed daily fluoxetine doses of 20 or 60 mg, or placebo [see Clinical Studies (14.3) ] . Only the 60 mg dose was statistically significantly superior to placebo in reducing the frequency of binge-eating and vomiting. Periodically reassess to determine the need for maintenance treatment. 2.4 Panic Disorder Initial Treatment — Initiate treatment with fluoxetine 10 mg/day. After one week, increase the dose to 20 mg/day. Consider a dose increase after several weeks if no clinical improvement is observed. Fluoxetine doses above 60 mg/day have not been systematically evaluated in patients with Panic Disorder. In the controlled clinical trials of fluoxetine supporting its effectiveness in the treatment of Panic Disorder, patients were administered fluoxetine doses in the range of 10 to 60 mg/day [see Clinical Studies (14.4) ] . The most frequently administered dose in the 2 flexible-dose clinical trials was 20 mg/day. Periodically reassess to determine the need for continued treatment. 2.5 Fluoxetine and Olanzapine in Combination: Depressive Episodes Associated with Bipolar I Disorder When using fluoxetine and olanzapine in combination, also refer to the Clinical Studies section of the package insert for Symbyax. Adult — Administer fluoxetine in combination with oral olanzapine once daily in the evening, without regard to meals, generally beginning with 5 mg of oral olanzapine and 20 mg of fluoxetine. Make dosage adjustments, if indicated, according to efficacy and tolerability within dose ranges of fluoxetine 20 to 50 mg and oral olanzapine 5 to 12.5 mg. Antidepressant efficacy was demonstrated with olanzapine and fluoxetine in combination with a dose range of olanzapine 6 to 12 mg and fluoxetine 25 to 50 mg. Safety of co-administration of doses above 18 mg olanzapine with 75 mg fluoxetine has not been evaluated in clinical studies. Periodically re-examine the need for continued pharmacotherapy. Children and adolescents (10-17 years of age) — Administer olanzapine and fluoxetine combination once daily in the evening, generally beginning with 2.5 mg of olanzapine and 20 mg of fluoxetine. Make dosage adjustments, if indicated, according to efficacy and tolerability. Safety of co-administration of doses above 12 mg of olanzapine with 50 mg of fluoxetine has not been evaluated in pediatric clinical studies. Periodically re-examine the need for continued pharmacotherapy. Safety and efficacy of fluoxetine in combination with olanzapine was determined in clinical trials supporting approval of Symbyax (fixed-dose combination of olanzapine and fluoxetine). Symbyax is dosed between 3 mg/25 mg (olanzapine/fluoxetine) per day and 12 mg/50 mg (olanzapine/fluoxetine) per day. The following table demonstrates the appropriate individual component doses of fluoxetine and olanzapine versus Symbyax. Adjust dosage, if indicated, with the individual components according to efficacy and tolerability. Table 1: Approximate Dose Correspondence Between Symbyax 1 and the Combination of Fluoxetine and Olanzapine For Symbyax (mg/day) Use in Combination Olanzapine (mg/day) Fluoxetine (mg/day) 1 Symbyax (olanzapine/fluoxetine HCL) is a fixed-dose combination of fluoxetine and olanzapine. 3 mg olanzapine/25 mg fluoxetine 2.5 20 6 mg olanzapine/25 mg fluoxetine 5 20 12 mg olanzapine/25 mg fluoxetine 10+2.5 20 6 mg olanzapine/50 mg fluoxetine 5 40+10 12 mg olanzapine/50 mg fluoxetine 10+2.5 40+10 Fluoxetine capsules monotherapy is not indicated for the treatment of depressive episodes associated with Bipolar I Disorder. 2.7 Dosing in Specific Populations Treatment of Pregnant Women — When treating pregnant women with fluoxetine, the physician should carefully consider the potential risks and potential benefits of treatment. Neonates exposed to SSRIs or SNRIs late in the third trimester have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding [see Use in Specific Populations (8.1) ]. Geriatric — Consider a lower or less frequent dosage for the elderly [see Use in Specific Populations (8.5) ]. Hepatic Impairment — As with many other medications, use a lower or less frequent dosage in patients with hepatic impairment [see Clinical Pharmacology (12.4) and Use in Specific Populations (8.6) ]. Concomitant Illness — Patients with concurrent disease or on multiple concomitant medications may require dosage adjustments [see Clinical Pharmacology (12.4) and Warnings and Precautions (5.12) ]. Fluoxetine capsules and Olanzapine in Combination — Use a starting dose of oral olanzapine 2.5 to 5 mg with fluoxetine 20 mg for patients with a predisposition to hypotensive reactions, patients with hepatic impairment, or patients who exhibit a combination of factors that may slow the metabolism of olanzapine or fluoxetine in combination (female gender, geriatric age, non-smoking status), or those patients who may be pharmacodynamically sensitive to olanzapine. Titrate slowly and adjust dosage as needed in patients who exhibit a combination of factors that may slow metabolism. Fluoxetine and olanzapine in combination have not been systematically studied in patients over 65 years of age or in patients less than 10 years of age [see Warnings and Precautions (5.16) and Drug Interactions (7.7) ] . 2.8 Discontinuation of Treatment Symptoms associated with discontinuation of fluoxetine, SNRIs, and SSRIs, have been reported [see Warnings and Precautions (5.15) ]. 2.9 Switching a Patient To or From a Monoamine Oxidase Inhibitor (MAOI) Intended to Treat Psychiatric Disorders At least 14 days should elapse between discontinuation of an MAOI intended to treat psychiatric disorders and initiation of therapy with fluoxetine. Conversely, at least 5 weeks should be allowed after stopping fluoxetine before starting an MAOI intended to treat psychiatric disorders [see Contraindications (4.1) ]. 2.10 Use of Fluoxetine with Other MAOIs such as Linezolid or Methylene Blue Do not start fluoxetine in a patient who is being treated with linezolid or intravenous methylene blue because there is an increased risk of serotonin syndrome. In a patient who requires more urgent treatment of a psychiatric condition, other interventions, including hospitalization, should be considered [see Contraindications (4.1) ]. In some cases, a patient already receiving fluoxetine therapy may require urgent treatment with linezolid or intravenous methylene blue. If acceptable alternatives to linezolid or intravenous methylene blue treatment are not available and the potential benefits of linezolid or intravenous methylene blue…
Paediatric
8.4 Pediatric Use Use of fluoxetin e in children - The efficacy of fluoxetine for the treatment of Major Depressive Disorder was demonstrated in two 8- to 9-week placebo-controlled clinical trials with 315 pediatric outpatients ages 8 to ≤18 [see Clinical Studies (14.1) ] . The efficacy of fluoxetine for the treatment of OCD was demonstrated in one 13-week placebo-controlled clinical trial with 103 pediatric outpatients ages 7 to <18 [see Clinical Studies (14.2) ] . The safety and effectiveness in pediatric patients <8 years of age in Major Depressive Disorder and <7 years of age in OCD have not been established. Fluoxetine pharmacokinetics were evaluated in 21 pediatric patients (ages 6 to ≤18) with Major Depressive Disorder or OCD [see Clinical Pharmacology (12.3) ] . The acute adverse reaction profiles observed in the 3 studies (N=418 randomized; 228 fluoxetine-treated, 190 placebo-treated) were generally similar to that observed in adult studies with fluoxetine. The longer-term adverse reaction profile observed in the 19-week Major Depressive Disorder study (N=219 randomized; 109 fluoxetine-treated, 110 placebo-treated) was also similar to that observed in adult trials with fluoxetine [see Adverse Reactions (6.1) ] . Manic reaction, including mania and hypomania, was reported in 6 (1 mania, 5 hypomania) out of 228 (2.6%) fluoxetine-treated patients and in 0 out of 190 (0%) placebo-treated patients. Mania/hypomania led to the discontinuation of 4 (1.8%) fluoxetine-treated patients from the acute phases of the 3 studies combined. Consequently, regular monitoring for the occurrence of mania/hypomania is recommended. As with other SSRIs, decreased weight gain has been observed in association with the use of fluoxetine in children and adolescent patients. After 19 weeks of treatment in a clinical trial, pediatric subjects treated with fluoxetine gained an average of 1.1 cm less in height and 1.1 kg less in weight than subjects treated with placebo. In addition, fluoxetine treatment was associated with a decrease in alkaline phosphatase levels. The safety of fluoxetine treatment for pediatric patients has not been systematically assessed for chronic treatment longer than several months in duration. In particular, there are no studies that directly evaluate the longer-term effects of fluoxetine on the growth, development and maturation of children and adolescent patients. Therefore, height and weight should be monitored periodically in pediatric patients receiving fluoxetine [see Warnings and Precautions (5.6) ] . Fluoxetine is approved for use in pediatric patients with MDD and OCD [see Box Warning and Warnings and Precautions (5.1 ) ] . Anyone considering the use of fluoxetine in a child or adolescent must balance the potential risks with the clinical need. Animal Data - Significant toxicity on muscle tissue, neurobehavior, reproductive organs, and bone development has been observed following exposure of juvenile rats to fluoxetine from weaning through maturity. Oral administration of fluoxetine to rats from weaning postnatal day 21 through adulthood day 90 at 3, 10, or 30 mg/kg/day was associated with testicular degeneration and necrosis, epididymal vacuolation and hypospermia (at 30 mg/kg/day corresponding to plasma exposures [AUC] approximately 5 to 10 times the average AUC in pediatric patients at the MRHD of 20 mg/day), increased serum levels of creatine kinase (at AUC as low as 1 to 2 times the average AUC in pediatric patients at the MRHD of 20 mg/day), skeletal muscle degeneration and necrosis, decreased femur length/growth and body weight gain (at AUC 5 to 10 times the average AUC in pediatric patients at the MRHD of 20 mg/day). The high dose of 30 mg/kg/day exceeded a maximum tolerated dose. When animals were evaluated after a drug-free period (up to 11 weeks after cessation of dosing), fluoxetine was associated with neurobehavioral abnormalities (decreased reactivity at AUC as low as approximately 0.1 to 0.2 times the average AUC in pediatric patients at the MRHD and learning deficit at the high dose), and reproductive functional impairment (decreased mating at all doses and impaired fertility at the high dose). In addition, the testicular and epididymal microscopic lesions and decreased sperm concentrations found in high dose group were also observed, indicating that the drug effects on reproductive organs are irreversible. The reversibility of fluoxetine-induced muscle damage was not assessed. These fluoxetine toxicities in juvenile rats have not been observed in adult animals. Plasma exposures (AUC) to fluoxetine in juvenile rats receiving 3, 10, or 30 mg/kg/day doses in this study are approximately 0.1 to 0.2, 1 to 2, and 5 to 10 times, respectively, the average exposure in pediatric patients receiving the MRHD of 20 mg/day. Rat exposures to the major metabolite, norfluoxetine, are approximately 0.3 to 0.8, 1 to 8, and 3 to 20 times, respectively, the pediatric exposure at the MRHD. A specific effect on bone development was reported in juvenile mice administered fluoxetine by the intraperitoneal route to 4 week old mice for 4 weeks at doses 0.5 and 2 times the oral MRHD of 20 mg/day on mg/m 2 basis. There was a decrease in bone mineralization and density at both doses, but the overall growth (body weight gain or femur length) was not affected. Use of fluoxetine in combination with olanzapine in children and adolescents: Safety and efficacy of fluoxetine and olanzapine in combination in patients 10 to 17 years of age have been established for the acute treatment of depressive episodes associated with Bipolar I Disorder. Safety and effectiveness of fluoxetine and olanzapine in combination in patients less than 10 years of age have not been established.
Renal
Review renal impairment dosing; many agents need CrCl/eGFR adjustment.
- CrCl 0–120: Confirm renal dosing in product SmPC / primary label.
Hepatic
Review hepatic impairment dosing; monitor LFTs if agent is hepatically cleared or hepatotoxic.
Safety
Drug interactions
- Professional use: confirm indication, dose, duration, monitoring and patient counselling points against current Kenya STG / EML and the product SmPC.
- Document allergy status and key interactions.
Safety
Adverse effects
- labeling: Suicidal Thoughts and Behaviors in Children, Adolescents, and Young Adults [see Boxed Warning and Warnings and Precautions (5.1) ] Serotonin Syndrome [see Warnings and Precautions (5.2) ] Allergic Reactions and Rash [see Warnings and Precautions (5.3) ] Screening Patients for Bipolar Disorder and Monitoring for Mania/Hypomania [see Warnings and Precautions (5.4) ] Seizures [see Warnings and Precautions (5.5) ] Altered Appetite and Weight [see Warnings and Precautions (5.6) ] Abnormal Bleeding [see Warnings and Precautions (5.7) ] Angle-Closure Glaucoma [see Warnings and Precautions (5.8) ] Hyponatremia [see Warnings and Precautions (5.9) ] Anxiety and Insomnia [see Warnings and Precautions (5.10) ] QT Prolongation [see Warnings and Precautions (5.11) ] Potential for Cognitive and Motor Impairment [see Warnings and Precautions (5.13) ] Discontinuation Adverse Reactions [see Warnings and Precautions (5.15) ] When using fluoxetine and olanzapine in combination, also refer to the Adverse Reactions section of the package insert for Symbyax.
- Most common adverse reactions (≥5% and at least twice that for placebo) associated with: Major Depressive Disorder, Obsessive Compulsive Disorder, Bulimia, and Panic Disorder: abnormal dreams, abnormal ejaculation, anorexia, anxiety, asthenia, diarrhea, dry mouth, dyspepsia, flu syndrome, impotence, insomnia, libido decreased, nausea, nervousness, pharyngitis, rash, sinusitis, somnolence, sweating, tremor, vasodilatation, and yawn ( 6.1 ) Fluoxetine and olanzapine in combination – Also refer to the Adverse Reactions section of the package insert for Symbyax ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Vensun Pharmaceuticals, Inc. at 1-800-385-1540 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 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 fluoxetine have been administered to 10,782 patients with various diagnoses in US clinical trials.
- In addition, there have been 425 patients administered fluoxetine in panic clinical trials.
- 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.
- 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 fluoxetine (incidence of at least 5% for fluoxetine 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 fluoxetine 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 Trials 1,2 Percentage of Patients Reporting Event Major Depressive Disorder OCD Bulimia Panic Disorder 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 fluoxetine Major Depressive Disorder
- N=410 placebo Major Depressive Disorder
- N=116 fluoxetine OCD
- N=43 placebo OCD
- N=14 fluoxetine bulimia
Use
Indications
- 1 INDICATIONS AND USAGE Fluoxetine is indicated for the treatment of: Acute and maintenance treatment of Major Depressive Disorder [see Clinical Studies (14.1) ] .
- Acute and maintenance treatment of obsessions and compulsions in patients with Obsessive Compulsive Disorder (OCD) [see Clinical Studies (14.2) ] .
- Acute and maintenance treatment of binge-eating and vomiting behaviors in patients with moderate to severe Bulimia Nervosa [see Clinical Studies (14.3) ] .
- Acute treatment of Panic Disorder, with or without agoraphobia [see Clinical Studies (14.4) ] .
- Fluoxetine and Olanzapine in Combination is indicated for the treatment of: Acute treatment of depressive episodes associated with Bipolar I Disorder.
- Fluoxetine monotherapy is not indicated for the treatment of depressive episodes associated with Bipolar I Disorder.
- When using Fluoxetine and olanzapine in combination, also refer to the Clinical Studies section of the package insert for Symbyax ® .
- Fluoxetine capsules are a selective serotonin reuptake inhibitor indicated for: Acute and maintenance treatment of Major Depressive Disorder (MDD) ( 1 ) Acute and maintenance treatment of Obsessive Compulsive Disorder (OCD) ( 1 ) Acute and maintenance treatment of Bulimia Nervosa ( 1 ) Acute treatment of Panic Disorder, with or without agoraphobia ( 1 ) Fluoxetine capsules and olanzapine in combination for treatment of: Acute Depressive Episodes Associated with Bipolar I Disorder ( 1 )
Pharmacology
Mode of action
Acts by selectively inhibiting the re-uptaking of serotonin [less sedative than tricylics].
Full mechanism text
Acts by selectively inhibiting the re-uptaking of serotonin [less sedative than tricylics]. Mechanism is agent-specific. At receptor, enzyme, ion channel, transporter or microbial target level, the drug alters a physiological or pathological pathway to produce its therapeutic effect. Confirm precise molecular mechanism in current SmPC / pharmacology reference for this INN before high-stakes decisions.
ADME
Pharmacokinetics & PD
| Onset | Product-specific |
|---|---|
| Duration | Product-specific |
| Route | See product SmPC |
| Absorption | by 1 to 2 hours, which is probably not clinically significant. Thus, fluoxetine may be administered with or without food. Protein Binding — Over the concentration range from 200 to 1000 ng/mL, approximately 94.5% of fluoxetine is bound in vitro to human serum proteins, including... |
| Metabolism | — Fluoxetine is extensively metabolized in the liver to norfluoxetine and a number of other unidentified metabolites. The only identified active metabolite, norfluoxetine, is formed by demethylation of fluoxetine. In animal models, S -norfluoxetine is a potent and selective inhib... |
| Elimination | appears to be hepatic |
| Half-life | of 1 to 3 days after acute administration and 4 to 6 days after chronic administration) and its active metabolite, norfluoxetine ( |
Full PK/PD text
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Although the exact mechanism of fluoxetine is unknown, it is presumed to be linked to its inhibition of CNS neuronal uptake of serotonin. 12.2 Pharmacodynamics Studies at clinically relevant doses in man have demonstrated that fluoxetine blocks the uptake of serotonin into human platelets. Studies in animals also suggest that fluoxetine is a much more potent uptake inhibitor of serotonin than of norepinephrine. Antagonism of muscarinic, histaminergic, and α 1 -adrenergic receptors has been hypothesized to be associated with various anticholinergic, sedative, and cardiovascular effects of classical tricyclic antidepressant (TCA) drugs. Fluoxetine binds to these and other membrane receptors from brain tissue much less potently in vitro than do the tricyclic drugs. 12.3 Pharmacokinetics Systemic Bioavailability — In man, following a single oral 40 mg dose, peak plasma concentrations of fluoxetine from 15 to 55 ng/mL are observed after 6 to 8 hours. Food does not appear to affect the systemic bioavailability of fluoxetine, although it may delay its absorption by 1 to 2 hours, which is probably not clinically significant. Thus, fluoxetine may be administered with or without food. Protein Binding — Over the concentration range from 200 to 1000 ng/mL, approximately 94.5% of fluoxetine is bound in vitro to human serum proteins, including albumin and α 1 -glycoprotein. The interaction between fluoxetine and other highly protein-bound drugs has not been fully evaluated, but may be important. Enantiomers — Fluoxetine is a racemic mixture (50/50) of R -fluoxetine and S -fluoxetine enantiomers. In animal models, both enantiomers are specific and potent serotonin uptake inhibitors with essentially equivalent pharmacologic activity. The S -fluoxetine enantiomer is eliminated more slowly and is the predominant enantiomer present in plasma at steady state. Metabolism — Fluoxetine is extensively metabolized in the liver to norfluoxetine and a number of other unidentified metabolites. The only identified active metabolite, norfluoxetine, is formed by demethylation of fluoxetine. In animal models, S -norfluoxetine is a potent and selective inhibitor of serotonin uptake and has activity essentially equivalent to R - or S -fluoxetine. R -norfluoxetine is significantly less potent than the parent drug in the inhibition of serotonin uptake. The primary route of elimination appears to be hepatic metabolism to inactive metabolites excreted by the kidney. Variability in Metabolism — A subset (about 7%) of the population has reduced activity of the drug metabolizing enzyme cytochrome P450 2D6 (CYP2D6). Such individuals are referred to as “poor metabolizers” of drugs such as debrisoquin, dextromethorphan, and the TCAs. In a study involving labeled and unlabeled enantiomers administered as a racemate, these individuals metabolized S -fluoxetine at a slower rate and thus achieved higher concentrations of S -fluoxetine. Consequently, concentrations of S -norfluoxetine at steady state were lower. The metabolism of R -fluoxetine in these poor metabolizers appears normal. When compared with normal metabolizers, the total sum at steady state of the plasma concentrations of the 4 active enantiomers was not significantly greater among poor metabolizers. Thus, the net pharmacodynamic activities were essentially the same. Alternative, nonsaturable pathways (non-2D6) also contribute to the metabolism of fluoxetine. This explains how fluoxetine achieves a steady-state concentration rather than increasing without limit. Because fluoxetine’s metabolism, like that of a number of other compounds including TCAs and other selective serotonin reuptake inhibitors (SSRIs), involves the CYP2D6 system, concomitant therapy with drugs also metabolized by this enzyme system (such as the TCAs) may lead to drug interactions [see Drug Interactions (7.7) ] . Accumulation and Slow Elimination — The relatively slow elimination of fluoxetine (elimination half-life of 1 to 3 days after acute administration and 4 to 6 days after chronic administration) and its active metabolite, norfluoxetine (elimination half-life of 4 to 16 days after acute and chronic administration), leads to significant accumulation of these active species in chronic use and delayed attainment of steady state, even when a fixed dose is used [see Warnings and Precautions (5.14) ] . After 30 days of dosing at 40 mg/day, plasma concentrations of fluoxetine in the range of 91 to 302 ng/mL and norfluoxetine in the range of 72 to 258 ng/mL have been observed. Plasma concentrations of fluoxetine were higher than those predicted by single-dose studies, because fluoxetine’s metabolism is not proportional to dose. Norfluoxetine, however, appears to have linear pharmacokinetics. Its mean terminal half-life after a single dose was 8.6 days and after multiple dosing was 9.3 days. Steady-state levels after prolonged dosing are similar to levels seen at 4 to 5 weeks. The long elimination half-lives of fluoxetine and norfluoxetine assure that, even when dosing is stopped, active drug substance will persist in the body for weeks (primarily depending on individual patient characteristics, previous dosing regimen, and length of previous therapy at discontinuation). This is of potential consequence when drug discontinuation is required or when drugs are prescribed that might interact with fluoxetine and norfluoxetine following the discontinuation of fluoxetine. 12.4 Specific Populations Liver Disease — As might be predicted from its primary site of metabolism, liver impairment can affect the elimination of fluoxetine. The elimination half-life of fluoxetine was prolonged in a study of cirrhotic patients, with a mean of 7.6 days compared with the range of 2 to 3 days seen in subjects without liver disease; norfluoxetine elimination was also delayed, with a mean duration of 12 days for cirrhotic patients compared with the range of 7 to 9 days in normal subjects. This suggests that the use of fluoxetine in patients with liver disease must be approached with caution. If fluoxetine is administered to patients with liver disease, a lower or less frequent dose should be used [see Dosage and Administration (2.7 ), Use in Specific Populations (8.6) ] . Renal Disease — In depressed patients on dialysis (N=12), fluoxetine administered as 20 mg once daily for 2 months produced steady-state fluoxetine and norfluoxetine plasma concentrations comparable with those seen in patients with normal renal function. While the possibility exists that renally excreted metabolites of fluoxetine may accumulate to higher levels in patients with severe renal dysfunction, use of a lower or less frequent dose is not routinely necessary in renally impaired patients. Geriatric Pharmacokinetics — The disposition of single doses of fluoxetine in healthy elderly subjects (>65 years of age) did not differ significantly from that in younger normal subjects. However, given the long half-life and nonlinear disposition of the drug, a single-dose study is not adequate to rule out the possibility of altered pharmacokinetics in the elderly, particularly if they have systemic illness or are receiving multiple drugs for concomitant diseases. The effects of age upon the metabolism of fluoxetine have been investigated in 260 elderly but otherwise healthy depressed patients (≥60 years of age) who received 20 mg fluoxetine for 6 weeks. Combined fluoxetine plus norfluoxetine plasma concentrations were 209.3 ± 85.7 ng/mL at the end of 6 weeks. No unusual age-associated pattern of adverse reactions was observed in those elderly patients. Pediatric Pharmacokinetics (children and adolescents) — Fluoxetine pharmacokinetics were evaluated in 21 pediatric patients (10 children ages 6 to <13, 11 adolescents ages 13 to <18) diagnosed with Major Depressive Disorder or Obsessive Compulsive Disorder (OCD). Fluoxetine 20 mg/day was administered for up to 62 days. The average steady-state concentrations of fluoxetine in these children were 2-fold higher than in adolescents (171 and 86 ng/mL, respectively). The average norfluoxetine steady-state concentrations in these children were 1.5-fold higher than in adolescents (195 and 113 ng/mL, respectively). These differences can be almost entirely explained by differences in weight. No gender-associated difference in fluoxetine pharmacokinetics was observed. Similar ranges of fluoxetine and norfluoxetine plasma concentrations were observed in another study in 94 pediatric patients (ages 8 to <18) diagnosed with Major Depressive Disorder. Higher average steady-state fluoxetine and norfluoxetine concentrations were observed in children relative to adults; however, these concentrations were within the range of concentrations observed in the adult population. As in adults, fluoxetine and norfluoxetine accumulated extensively following multiple oral dosing; steady-state concentrations were achieved within 3 to 4 weeks of daily dosing.
Kenya
Brands & prices
| Brand | Company | Pack | KES |
|---|---|---|---|
| DEPROZET | DAIMA BIASHARA / Wholesale Import | 20MG TABS 100*S -DDA | 1,182.50 |
| PRODEP | DAIMA BIASHARA / Wholesale Import | 20MG CAPS 60*S -DDA | 2,508.33 |
Special populations
Pregnancy & lactation
Pregnancy
8.1 Pregnancy Pregnancy Category C — Fluoxetine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. All pregnancies have a background risk of birth defects, loss, or other adverse outcome regardless of drug exposure. Treatment of Pregnant Women during the First Trimester — There are no adequate and well-controlled clinical studies on the use of fluoxetine in pregnant women. Results of a number of published epidemiological studies assessing the risk of fluoxetine exposure during the first trimester of pregnancy have demonstrated inconsistent results. More than 10 cohort studies and case-control studies failed to demonstrate an increased risk for congenital malformations overall. However, one prospective cohort study conducted by the European Network of Teratology Information Services reported an increased risk of cardiovascular malformations in infants born to women (N = 253) exposed to fluoxetine during the first trimester of pregnancy compared to infants of women (N = 1,359) who were not exposed to fluoxetine. There was no specific pattern of cardiovascular malformations. Overall, however, a causal relationship has not been established. Nonteratogenic Effects — Neonates exposed to fluoxetine and other SSRIs or serotonin and norepinephrine reuptake inhibitors (SNRIs), late in the third trimester have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding. Such complications can arise immediately upon delivery. Reported clinical findings have included respiratory distress, cyanosis, apnea, seizures, temperature instability, feeding difficulty, vomiting, hypoglycemia, hypotonia, hypertonia, hyperreflexia, tremor, jitteriness, irritability, and constant crying. These features are consistent with either a direct toxic effect of SSRIs and SNRIs or, possibly, a drug discontinuation syndrome. It should be noted that, in some cases, the clinical picture is consistent with serotonin syndrome [see Warnings and Precautions (5.2) ]. Infants exposed to SSRIs in pregnancy may have an increased risk for persistent pulmonary hypertension of the newborn (PPHN). PPHN occurs in 1 to 2 per 1,000 live births in the general population and is associated with substantial neonatal morbidity and mortality. Several recent epidemiological studies suggest a positive statistical association between SSRI use (including fluoxetine) in pregnancy and PPHN. Other studies do not show a significant statistical association. Physicians should also note the results of a prospective longitudinal study of 201 pregnant women with a history of major depression, who were either on antidepressants or had received antidepressants less than 12 weeks prior to their last menstrual period, and were in remission. Women who discontinued antidepressant medication during pregnancy showed a significant increase in relapse of their major depression compared to those women who remained on antidepressant medication throughout pregnancy. When treating a pregnant woman with fluoxetine, the physician should carefully consider both the potential risks of taking an SSRI, along with the established benefits of treating depression with an antidepressant. The decision can only be made on a case by case basis [see Dosage and Administration (2.7) ] . Animal Data — In embryo-fetal development studies in rats and rabbits, there was no evidence of teratogenicity following administration of fluoxetine at doses up to 12.5 and 15 mg/kg/day, respectively (1.5 and 3.6 times, respectively, the maximum recommended human dose (MRHD) of 80 mg on a mg/m 2 basis) throughout organogenesis. However, in rat reproduction studies, an increase in stillborn pups, a decrease in pup weight, and an increase in pup deaths during the first 7 days postpartum occurred following maternal exposure to 12 mg/kg/day (1.5 times the MRHD on a mg/m 2 basis) during gestation or 7.5 mg/kg/day (0.9 times the MRHD on a mg/m 2 basis) during gestation and lactation. There was no evidence of developmental neurotoxicity in the surviving offspring of rats treated with 12 mg/kg/day during gestation. The no-effect dose for rat pup mortality was 5 mg/kg/day (0.6 times the MRHD on a mg/m 2 basis).
Lactation
8.3 Nursing Mothers Because fluoxetine is excreted in human milk, nursing while on fluoxetine is not recommended. In one breast-milk sample, the concentration of fluoxetine plus norfluoxetine was 70.4 ng/mL. The concentration in the mother’s plasma was 295.0 ng/mL. No adverse effects on the infant were reported. In another case, an infant nursed by a mother on fluoxetine developed crying, sleep disturbance, vomiting, and watery stools. The infant’s plasma drug levels were 340 ng/mL of fluoxetine and 208 ng/mL of norfluoxetine on the second day of feeding.
Diet
Food & alcohol
- Drug & food interactions (label) 7 DRUG INTERACTIONS As with all drugs, the potential for interaction by a variety of mechanisms (e.g., pharmacodynamic, pharmacokinetic drug inhibition or enhancement, etc.) is a possibility. Monoamine Oxidase Inhibitors (MAOIs): ( 2.9 , 2.10 , 4.1 , 5.2 ) Drugs Metabolized by CYP2D6: Fluoxetine is a potent inhibitor of CYP2D6 enzyme pathway ( 7.7 ) Tricyclic Antidepressants (TCAs): Monitor TCA levels during coadministration with fluoxetine or when fluoxetine has been recently discontinued ( 5.2 , 7.7 ) CNS Acting Drugs: Caution should be used when taken in combination with other centrally acting drugs ( 7.2 ) Benzodiazepines: Diazepam – increased t½, alprazolam - further psychomotor performance decrement due to increased levels ( 7.7 ) Antipsychotics: Potential for elevation of haloperidol and clozapine levels ( 7.7 ) Anticonvulsants: Potential for elevated phenytoin and carbamazepine levels and clinical anticonvulsant toxicity ( 7.7 ) Serotonergic Drugs: ( 2.9 , 2.10 , 4.1 , 5.2 ) Drugs that Interfere with Hemostasis (e.g. NSAIDs, Aspirin, Warfarin): May potentiate the risk of bleeding ( 7.4 ) Drugs Tightly Bound to Plasma Proteins: May cause a shift in plasma concentrations ( 7.6 , 7.7 ) Olanzapine: When used in combination with fluoxetine, also refer to the Drug Interactions section of the package insert for Symbyax ( 7.7 ) Drugs that Prolong the QT Interval: Do not use fluoxetine with thioridazine or pimozide. Use with caution in combination with other drugs that prolong the QT interval ( 4.2 , 5.11 , 7.7 , 7.8 ) 7.1 Monoamine Oxidase Inhibitors (MAOI) [see Dosage and Administration (2.9, 2.10) , Contraindications (4.1) , and Warnings and Precautions (5.2) ]. 7.2 CNS Acting Drugs Caution is advised if the concomitant administration of fluoxetine and such drugs is required. In evaluating individual cases, consideration should be given to using lower initial doses of the concomitantly administered drugs, using conservative titration schedules, and monitoring of clinical status [see Clinical Pharmacology (12.3) ] . 7.3 Serotonergic Drugs [see Dosage and Administration (2.9, 2.10) , Contraindications (4.1) , and Warnings and Precautions (5.2) ]. 7.4 Drugs that Interfere with Hemostasis (e.g., NSAIDs, Aspirin, Warfarin) Serotonin release by platelets plays an important role in hemostasis. Epidemiological studies of the case-control and cohort design that have demonstrated an association between use of psychotropic drugs that interfere with serotonin reuptake and the occurrence of upper gastrointestinal bleeding have also shown that concurrent use of an NSAID or aspirin may potentiate this risk of bleeding. Altered anticoagulant effects, including increased bleeding, have been reported when SNRIs or SSRIs are coadministered with warfarin. Patients receiving warfarin therapy should be carefully monitored when fluoxetine is initiated or discontinued [see Warnings and Precautions (5.7) ] . 7.5 Electroconvulsive Therapy (ECT) There are no clinical stu
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Sources & disclaimer
Source: Local active-ingredient clinical extract; FDA drug label via OpenFDA/DailyMed; Professional class pharmacology (Therapeutic agent (verify pharmacological class))
Clinical review date not recorded.
Decision support only — not a substitute for clinical judgment, product SmPC, or Kenya STG/EML.