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Prozac Capsules Dosage

Generic name: Fluoxetine hydrochloride 10mg
Dosage form: capsule
Drug class: Selective serotonin reuptake inhibitors

Medically reviewed by Drugs.com. Last updated on Aug 18, 2023.

Major Depressive Disorder

Initial Treatment

Adult — Initiate PROZAC 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 PROZAC 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)].

Obsessive Compulsive Disorder

Initial Treatment

Adult — Initiate PROZAC 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.

Bulimia Nervosa

Initial Treatment — Administer PROZAC 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.

Panic Disorder

Initial Treatment — Initiate treatment with PROZAC 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.

PROZAC and Olanzapine in Combination: Depressive Episodes Associated with Bipolar I Disorder

When using PROZAC 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 PROZAC and olanzapine versus Symbyax. Adjust dosage, if indicated, with the individual components according to efficacy and tolerability.

Table 1: Approximate Dose Correspondence Between Symbyax1 and the Combination of PROZAC and Olanzapine

1 Symbyax (olanzapine/fluoxetine HCL) is a fixed-dose combination of PROZAC and olanzapine.

For
Symbyax
(mg/day)
Use in Combination
Olanzapine
(mg/day)
PROZAC
(mg/day)
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

PROZAC monotherapy is not indicated for the treatment of depressive episodes associated with Bipolar I Disorder.

PROZAC and Olanzapine in Combination: Treatment Resistant Depression

When using PROZAC and olanzapine in combination, also refer to the Clinical Studies section of the package insert for Symbyax.

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. Adjust dosage, if indicated, according to efficacy and tolerability within dose ranges of fluoxetine 20 to 50 mg and oral olanzapine 5 to 20 mg. Antidepressant efficacy was demonstrated with olanzapine and fluoxetine in combination with a dose range of olanzapine 6 to 18 mg and fluoxetine 25 to 50 mg.

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. Table 1 demonstrates the appropriate individual component doses of PROZAC and olanzapine versus Symbyax. Adjust dosage, if indicated, with the individual components according to efficacy and tolerability.

Periodically re-examine the need for continued pharmacotherapy.

Safety of coadministration of doses above 18 mg olanzapine with 75 mg fluoxetine has not been evaluated in clinical studies.

PROZAC monotherapy is not indicated for the treatment of treatment resistant depression (Major Depressive Disorder in patients who do not respond to 2 antidepressants of adequate dose and duration in the current episode).

Dosing in Specific Populations

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)].

PROZAC 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. PROZAC 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)].

Discontinuation of Treatment

Symptoms associated with discontinuation of fluoxetine, SNRIs, and SSRIs, have been reported [see Warnings and Precautions (5.15)].

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 PROZAC. Conversely, at least 5 weeks should be allowed after stopping PROZAC before starting an MAOI intended to treat psychiatric disorders [see Contraindications (4.1)].

Use of PROZAC with Other MAOIs such as Linezolid or Methylene Blue

Do not start PROZAC 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 PROZAC 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 treatment are judged to outweigh the risks of serotonin syndrome in a particular patient, PROZAC should be stopped promptly, and linezolid or intravenous methylene blue can be administered. The patient should be monitored for symptoms of serotonin syndrome for five weeks or until 24 hours after the last dose of linezolid or intravenous methylene blue, whichever comes first. Therapy with PROZAC may be resumed 24 hours after the last dose of linezolid or intravenous methylene blue [see Warnings and Precautions (5.2)].

The risk of administering methylene blue by non-intravenous routes (such as oral tablets or by local injection) or in intravenous doses much lower than 1 mg/kg with PROZAC is unclear. The healthcare provider should, nevertheless, be aware of the possibility of emergent symptoms of serotonin syndrome with such use [see Warnings and Precautions (5.2)].

Frequently asked questions

Further information

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