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Pronunciation |
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(floo
OKS e
teen) |

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U.S. Brand
Names |
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Prozac® |

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Generic
Available |
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No |

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Synonyms |
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Fluoxetine Hydrochloride |

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Pharmacological Index |
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Antidepressant, Selective Serotonin Reuptake Inhibitor |

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Use |
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Treatment of major depression; treatment of binge-eating and vomiting in
patients with moderate-to-severe bulimia nervosa; obsessive-compulsive disorder
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Pregnancy Risk
Factor |
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C |

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Contraindications |
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Hypersensitivity to this agent. Use of MAO inhibitors within prior 14 days; a
MAO inhibitor should not be initiated until 5 weeks after the discontinuation of
fluoxetine. |

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Warnings/Precautions |
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Potential for severe reaction when used with MAO inhibitors - serotonin
syndrome (hyperthermia, muscular rigidity, mental status changes/agitation,
autonomic instability) may occur. Fluoxetine use has been associated with
occurrences of significant rash and allergic events, including vasculitis,
anaphylactoid reactions, and pulmonary inflammatory disease. May precipitate a
shift to mania or hypomania in patients with bipolar disease. May cause
insomnia, anxiety, nervousness or anorexia. Use with caution in patients where
weight loss is undesirable. May impair cognitive or motor performance - caution
operating hazardous machinery or driving. Use caution in patients with
depression, particularly if suicidal risk may be present. Use caution in
patients with a previous seizure disorder or condition predisposing to seizures
such as brain damage, alcoholism, or concurrent therapy with other drugs which
lower the seizure threshold. Use with caution in patients with hepatic or renal
dysfunction and in elderly patients. May cause hyponatremia/SIADH. May increase
the risks associated with electroconvulsive treatment. Use with caution in
patients at risk of bleeding or receiving concurrent anticoagulant therapy - may
cause impairment in platelet function. May alter glycemic control in patients
with diabetes. Due to the long half-life of fluoxetine and its metabolites, the
effects and interactions noted may persist for prolonged periods following
discontinuation. May cause or exacerbate sexual
dysfunction. |

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Adverse
Reactions |
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Predominant adverse effects are CNS and GI
Central nervous system: Headache, nervousness, insomnia, anxiety, somnolence
Gastrointestinal: Nausea, diarrhea, xerostomia, anorexia
Neuromuscular & skeletal: Weakness
1% to 10%:
Cardiovascular: Vasodilation, palpitation, hypertension
Central nervous system: Amnesia, confusion, emotional lability, sleep
disorder, dizziness, agitation, yawning
Dermatologic: Rash, pruritus
Endocrine & metabolic: SIADH, hypoglycemia, hyponatremia (elderly or
volume-depleted patients)
Gastrointestinal: Dyspepsia, increased appetite, constipation, vomiting,
flatulence, weight loss, weight gain
Genitourinary: Sexual dysfunction, urinary frequency
Neuromuscular & skeletal: Tremor
Ocular: Abnormal vision
Respiratory: Pharyngitis
Miscellaneous: Diaphoresis, fever, flu syndrome
<1%: Extrapyramidal reactions (rare), euphoria, hallucinations, hostility,
dehydration, edema, gout, hypercholesteremia, hypokalemia, arthritis, bone pain,
bursitis, leg cramps, angina, CHF, arrhythmia, hypotension, myocardial
infarction, syncope, tachycardia, aphthous stomatitis, cholelithiasis, colitis,
dysphagia, gastritis, glossitis, hypothyroidism, asthma, epistaxis, hiccup,
hyperventilation, anemia, ecchymosis, albuminuria, amenorrhea, visual
disturbances, anaphylactoid reactions, allergies, suicidal ideation, erythema
nodosum |

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Overdosage/Toxicology |
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Symptoms of overdose include ataxia, sedation, and coma; respiratory
depression may occur, especially with coingestion of alcohol or other drugs;
seizures very rarely occur |

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Drug
Interactions |
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CYP2D6 enzyme substrate (minor), CYP3A3/4 enzyme substrate; CYP2C9 enzyme
inducer; CYP1A2, 2C19, 2D6, and 3A3/4 enzyme inhibitor
Fluoxetine inhibits the metabolism of tricyclic antidepressants
(amitriptyline, desipramine, imipramine, nortriptyline) resulting is elevated
serum levels; if combination is warranted, a low dose of TCA (10-25 mg/day)
should be utilized
Fluoxetine may cause hyponatremia; additive hyponatremic effects may be seen
with combined use of a loop diuretic (bumetanide, furosemide, torsemide);
monitor for hyponatremia
Fluoxetine inhibits the reuptake of serotonin; combined use with a serotonin
agonist (buspirone) may cause serotonin syndrome
Fluoxetine may inhibit the metabolism of carbamazepine resulting in increased
carbamazepine levels and toxicity; monitor for altered CBZ response
Cyproheptadine, a serotonin antagonist may inhibit the effects of serotonin
reuptake inhibitors (fluoxetine); monitor for altered antidepressant response
Fluoxetine inhibits the metabolism of dextromethorphan; visual hallucinations
occurred in a patient receiving this combination; monitor for serotonin syndrome
Fluoxetine may inhibit the metabolism of haloperidol and cause extrapyramidal
symptoms (EPS); monitor patients for EPS if combination is utilized
Fluoxetine should not be used with nonselective MAOIs (isocarboxazid,
phenelzine). Fatal reactions have been reported. Wait 5 weeks after stopping
fluoxetine before starting an MAOI and 2 weeks after stopping an MAOI before
starting fluoxetine.
Patients receiving fluoxetine and lithium have developed neurotoxicity. If
combination is used, monitor for neurotoxicity
Fluoxetine may inhibit the metabolism of metoprolol and propranolol resulting
in cardiac toxicity; monitor for bradycardia, hypotension, and heart failure if
combination is used
Fluoxetine inhibits the reuptake of serotonin; combined use with other drugs
which inhibit the reuptake (nefazodone, sibutramine) may cause serotonin
syndrome. Monitor patient for altered response with nefazodone; avoid
sibutramine combination.
Fluoxetine inhibits the metabolism of phenytoin and may result in phenytoin
toxicity; monitor for phenytoin toxicity (ataxia, confusion, dizziness,
nystagmus, involuntary muscle movement)
Fluoxetine has been reported to cause mania or hypertension when combined
with selegiline; this combination is best avoided
Fluoxetine may inhibit the metabolism of lovastatin and simvastatin resulting
in myositis and rhabdomyolysis; these combinations are best avoided
Fluoxetine combined with tramadol (serotonergic effects) may cause serotonin
syndrome; monitor
Fluoxetine may inhibit the metabolism of trazodone resulting in increased
toxicity; monitor
Fluoxetine inhibits the reuptake of serotonin; combination with tryptophan, a
serotonin precursor, may cause agitation and restlessness; this combination is
best avoided
Fluoxetine may alter the hypoprothombinemic response to warfarin; monitor
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Stability |
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All dosage forms should be stored at controlled room temperature
(15°C to 30°C or
50°F to 86°F); oral liquid should be
dispensed in a light-resistant container |

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Mechanism of
Action |
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Inhibits CNS neuron serotonin reuptake; minimal or no effect on reuptake of
norepinephrine or dopamine; does not significantly bind to alpha-adrenergic,
histamine or cholinergic receptors |

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Pharmacodynamics/Kinetics |
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Onset of effect: >2-4 weeks for therapeutic effects
Peak antidepressant effect: After >4 weeks
Absorption: Oral: Well absorbed
Metabolism: To norfluoxetine (active)
Half-life: Adults: 2-3 days; due to long half-life, resolution of adverse
reactions after discontinuation may be slow
Time to peak serum concentration: Within 4-8 hours
Elimination: In urine as fluoxetine (2.5% to 5%) and norfluoxetine (10%)
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Usual Dosage |
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Oral:
Adults: 20 mg/day in the morning; may increase after several weeks by 20
mg/day increments; maximum: 80 mg/day; doses >20 mg should be divided into
morning and noon doses
Usual dosage range:
20-40 mg/day for depression and 40-80 mg for OCD
20-60 mg/day for obesity
60-80 mg/day for bulimia nervosa
Note: Lower doses of 5 mg/day have been used for initial treatment
Elderly: Some patients may require an initial dose of 10 mg/day with dosage
increases of 10 and 20 mg every several weeks as tolerated; should not be taken
at night unless patient experiences sedation
Dosing adjustment in renal impairment:
Single dose studies: Pharmacokinetics of fluoxetine and norfluoxetine were
similar among subjects with all levels of impaired renal function, including
anephric patients on chronic hemodialysis
Chronic administration: Additional accumulation of fluoxetine or
norfluoxetine may occur in patients with severely impaired renal function
Hemodialysis: Not removed by hemodialysis
Dosing adjustment in hepatic impairment: Elimination half-life of
fluoxetine is prolonged in patients with hepatic impairment; a lower or less
frequent dose of fluoxetine should be used in these patients
Cirrhosis patients: Administer a lower dose or less frequent dosing interval
Compensated cirrhosis without ascites: Administer 50% of normal dose
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Dietary
Considerations |
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Alcohol: Avoid use |

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Reference Range |
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Therapeutic levels have not been well established
Toxic: Fluoxetine plus norfluoxetine: >2000 ng/mL |

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Test
Interactions |
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albumin in
urine
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Dental Health: Local
Anesthetic/Vasoconstrictor
Precautions |
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Although caution should be used in patients taking tricyclic antidepressants,
no interactions have been reported with vasoconstrictors and fluoxetine, a
nontricyclic antidepressant which acts to increase
serotonin |

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Dental Health:
Effects on Dental Treatment |
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>10% of patients experience dry mouth |

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Patient
Information |
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Take exactly as directed (do not increase dose or frequency); may take 2-3
weeks to achieve desired results; may cause physical and/or psychological
dependence. Take once-a-day dose in the morning to reduce incidence of insomnia.
Avoid excessive alcohol, caffeine, and other prescription or OTC medications not
approved by prescriber. Maintain adequate hydration (2-3 L/day of fluids unless
instructed to restrict fluid intake). You may experience drowsiness,
lightheadedness, impaired coordination, dizziness, or blurred vision (use
caution when driving or engaging in tasks requiring alertness until response to
drug is known); constipation (increased exercise, fluids, or dietary fruit and
fiber may help); anorexia (maintain regular dietary intake to avoid excessive
weight loss); or postural hypotension (use caution when climbing stairs or
changing position from lying or sitting to standing). If diabetic, monitor serum
glucose closely (may cause hypoglycemia). Report persistent CNS effects
(nervousness, restlessness, insomnia, anxiety, excitation, headache, sedation);
rash or skin irritation; muscle cramping, tremors, or change in gait;
respiratory depression or difficulty breathing; or worsening of condition.
Breast-feeding precautions: Breast-feeding is not
recommended. |

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Nursing
Implications |
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Offer patient sugarless hard candy for dry mouth |

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Dosage Forms |
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Capsule, as hydrochloride: 10 mg, 20 mg, 40 mg
Liquid, as hydrochloride (mint flavor): 20 mg/5 mL (120 mL)
Tablet, as hydrochloride: 10 mg, 20 mg |

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Extemporaneous
Preparations |
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A 20 mg capsule may be mixed with 4 oz of water, apple juice, or
Gatorade® to provide a solution that is stable for 14 days
under refrigeration |

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References |
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Amitai Y, Kennedy E, De Sandre P, et al,
"Red Cell and Plasma Concentrations of Fluoxetine and Norfluoxetine," Vet Hum
Toxicol, 1993, 35(2):134-6.
Beasley CM, Bosomworth JC, and Wernicke JF,
"Fluoxetine: Relationships Among Dose, Response, Adverse Events, and Plasma Concentrations in the Treatment of Depression,"
Psychopharmacol Bull, 1990, 26(1):18-24.
Black B and Uhde TW,
"Treatment of Elective Mutism With Fluoxetine: A Double Blind, Placebo-Controlled Study,"
J Am Acad Child Adolesc Psychiatry, 1994, 33(7):1000-6.
Borys DJ, Setzer SC, Ling LJ, et al,
"Acute Fluoxetine Overdose: A Report of 234 Cases," Am J Emerg Med, 1992,
10(2):115-20.
Borys DJ, Setzer SC, Ling LJ, et al,
"The Effects of Fluoxetine in the Overdose Patient," J Toxicol Clin
Toxicol, 1990, 28(3):331-40.
Braitberg G and Curry SC, "Seizure After Isolated Fluoxetine Overdose,"
Ann Emerg Med, 1995, 26(2):234-7.
Como PG and Kurlan R,
"An Open-Label Trial of Fluoxetine for Obsessive-Compulsive Disorder in Gilles de la Tourette's Syndrome,"
Neurology, 1991, 41(6):872-4.
Feighner JP and Cohn JB,
"Double-blind Comparative Trials of Fluoxetine and Doxepin in Geriatric Patients With Major Depressive Disorder,"
J Clin Psychiatry, 1985, 46(3 Pt 2):20-5.
Garcia-Monco JC, Padierna A, and Gomez Beldarrain M,
"Selegiline, Fluoxetine, and Depression in Parkinson's Disease," Mov
Disord, 1995, 10(3):352.
Gardner SF, Rutherford WF, Munger MA, et al,
"Drug-Induced Supraventricular Tachycardia: A Case Report of Fluoxetine," Ann
Emerg Med, 1991, 20(2):194-7.
Gonzalez-Rothi RJ, Zander DS, and Ros PR,
"Fluoxetine Hydrochloride (Prozac®)-Induced Pulmonary
Disease," Chest, 1995, 107(6):1763-5.
Grounds D, Stocky A, Evans P, et al, "Antidepressants and Side Effects,"
Aust N Z J Psychiatry, 1995, 29(1):156-7.
Horton RC and Bonser RS, "Interaction Between Cyclosporin and Fluoxetine,"
BMJ, 1995, 311(7002):422.
Jackson C, Carson W, Markowitz J, et al,
"SIADH Associated With Fluoxetine and Sertraline Therapy," Am J
Psychiatry, 1995, 152(5):809-10.
Jennison TA, Brown P, Crossett J, et al,
"A High-Performance Liquid Chromatographic Method for Quantitating Bupropion in Human Plasma or Serum,"
J Anal Toxicol, 1995, 19(2):69-72.
Kingsbury SJ and Puckett KM,
"Effects of Fluoxetine on Serum Clozapine Levels," Am J Psychiatry, 1995,
152(3):473-4.
Kurlan R, Como PG, Deeley C, et al,
"A Pilot Controlled Study of Fluoxetine for Obsessive-Compulsive Symptoms in Children With Tourette's Syndrome,"
Clin Neuropharmacol, 1993, 16(2):167-72.
Lemberger L, Bergstrom RF, Wolen RL, et al,
"Fluoxetine: Clinical Pharmacology and Physiologic Disposition," J Clin
Psychiatry, 1985, 46(3 Pt 2):14-9.
McKenzie LJ and Risch SC,
"Fibrocystic Breast Disease Following Treatment With Selective Serotonin Reuptake Inhibitors,"
Am J Psychiatry, 1995, 152(3):471.
Pollak PT, Sketris IS, MacKenzie SL, et al,
"Delirium Probably Induced by Clarithromycin in a Patient Receiving Fluoxetine,"
Ann Pharmacother, 1995, 29(5):486-8.
Riddle MA, Hardin MT, King R, et al,
"Fluoxetine Treatment of Children and Adolescents With Tourette's and Obsessive-Compulsive Disorders: Preliminary Clinical Experience,"
J Am Acad Child Adolesc Psychiatry, 1990, 29(1):45-8.
Riddle MA, Scahill L, King RA, et al,
"Double-Blind, Crossover Trial of Fluoxetine and Placebo in Children and Adolescents With Obsessive-Compulsive Disorder,"
J Am Acad Child Adolesc Psychiatry, 1992, 31(6):1062-9.
Roose SP, Glassman AH, Attia E, et al,
"Comparative Efficacy of Selective Serotonin Reuptake Inhibitors and Tricyclics in the Treatment of Melancholia,"
Am J Psychiatry, 1994, 151(12):1735-9.
Schone W and Ludwig M,
"A Double-Blind Study of Paroxetine Compared With Fluoxetine in Geriatric Patients With Major Depression,"
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"Fluoxetine Ingestion: A One Year Retrospective Study," Vet Hum Toxicol,
1990, 32(2):153-5.
Steiner M, Steinberg S, Stewart D, et al,
"Fluoxetine in the Treatment of Premenstrual Dysphoria. Canadian Fluoxetine/Premenstrual Dysphoria Collaborative Study Group,"
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Sternbach H, "Fluoxetine-Clomipramine Interaction," J Clin Psychiatry,
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