Fluoxetine capsules
Dosage Form: Capsules
Revised MAY 2007
11001014
Rx only
(Three Medication Guides Attached)
Warning
Suicidality and Antidepressant Drugs
Antidepressants increased the risk compared to placebo of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults in short-term studies of major depressive disorder (MDD) and other psychiatric disorders. Anyone considering the use of Fluoxetine capsules or any other antidepressant in a child, adolescent, or young adult must balance this risk with the clinical need. Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24; there was a reduction in risk with antidepressants compared to placebo in adults aged 65 and older. Depression and certain other psychiatric disorders are themselves associated with increases in the risk of suicide. Patients of all ages who are started on antidepressant therapy should be monitored appropriately and observed closely for clinical worsening, suicidality, or unusual changes in behavior. Families and caregivers should be advised of the need for close observation and communication with the prescriber. Fluoxetine is approved for use in pediatric patients with MDD and obsessive compulsive disorder (OCD). (See WARNINGS: Clinical Worsening and Suicide Risk, PRECAUTIONS: Information for Patients, and PRECAUTIONS: Pediatric Use)
DESCRIPTION:
Fluoxetine Hydrochloride is a psychotropic drug for oral administration. It is also marketed for the treatment of premenstrual dysphoric disorder (Sarafem®, Fluoxetine hydrochloride). It is designated (±)-N-methyl-3-phenyl-3-[(α,α,α-trifluoro-p-tolyl)oxy]propylamine hydrochloride. Fluoxetine Hydrochloride has the following structural formula:
 C17H18F3NO•HCl Molecular Weight: 345.79
Fluoxetine hydrochloride is a white to off-white crystalline solid with a solubility of 14 mg/mL in water.
Each capsule, for oral administration, contains Fluoxetine hydrochloride equivalent to 10 mg (32.3 µmol) or 20 mg (64.7 µmol) of Fluoxetine. In addition, each capsule contains the following inactive ingredients: butylparaben, corn starch, D&C yellow no. 10 aluminum lake, D&C red no. 28, edetate calcium disodium, FD&C blue no. 1, FD&C blue no. 1 aluminum lake, FD&C blue no. 2 aluminum lake, FD&C red no. 40 aluminum lake, gelatin, lactose monohydrate, methylparaben, microcrystalline cellulose, pharmaceutical glaze, propylene glycol, propylparaben, sodium lauryl sulfate, sodium propionate, stearic acid, synthetic black iron oxide, and titanium dioxide. In addition, the 10 mg contains D&C yellow no. 10 and the 20 mg contains carboxymethyl cellulose sodium.
CLINICAL PHARMACOLOGY:
Pharmacodynamics:
The antidepressant, antiobsessive-compulsive, and antibulimic actions of Fluoxetine are presumed to be linked to its inhibition of CNS neuronal uptake of serotonin. 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 α1-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.
Absorption, Distribution, Metabolism, and Excretion:
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.
The capsule, tablet, and oral solution dosage forms of Fluoxetine are bioequivalent. 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 1,000 ng/mL, approximately 94.5% of Fluoxetine is bound in vitro to human serum proteins, including albumin and α1-glycoprotein. The interaction between Fluoxetine and other highly protein-bound drugs has not been fully evaluated, but may be important (see PRECAUTIONS).
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.
Clinical Issues Related to Metabolism/Elimination:
The complexity of the metabolism of Fluoxetine has several consequences that may potentially affect Fluoxetine’s clinical use.
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 four 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, 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 under PRECAUTIONS).
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. 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.
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 to 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 to 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 PRECAUTIONS and DOSAGE AND ADMINISTRATION).
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 to 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 (see Use in Patients with Concomitant Illness under PRECAUTIONS and DOSAGE AND ADMINISTRATION).
Age:
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 events 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.
CLINICAL TRIALS:
Major Depressive Disorder: Daily Dosing:
Adult:
The efficacy of Fluoxetine for the treatment of patients with major depressive disorder (≥ 18 years of age) has been studied in 5- and 6-week placebo-controlled trials. Fluoxetine was shown to be significantly more effective than placebo as measured by the Hamilton Depression Rating Scale (HAM-D). Fluoxetine was also significantly more effective than placebo on the HAM-D subscores for depressed mood, sleep disturbance, and the anxiety subfactor.
Two 6-week controlled studies (N=671, randomized) comparing Fluoxetine 20 mg, and placebo have shown Fluoxetine 20 mg daily, to be effective in the treatment of elderly patients (≥ 60 years of age) with major depressive disorder. In these studies, Fluoxetine produced a significantly higher rate of response and remission as defined, respectively, by a 50% decrease in the HAM-D score and a total endpoint HAM-D score of ≤ 8. Fluoxetine was well tolerated and the rate of treatment discontinuations due to adverse events did not differ between Fluoxetine (12%) and placebo (9%).
A study was conducted involving depressed outpatients who had responded (modified HAMD-17 score of ≤ 7 during each of the last 3 weeks of open-label treatment and absence of major depressive disorder by DSM-III-R criteria) by the end of an initial 12-week open treatment phase on Fluoxetine 20 mg/day. These patients (N=298) were randomized to continuation on double-blind Fluoxetine 20 mg/day or placebo. At 38 weeks (50 weeks total), a statistically significantly lower relapse rate (defined as symptoms sufficient to meet a diagnosis of major depressive disorder for 2 weeks or a modified HAMD-17 score of ≥ 14 for 3 weeks) was observed for patients taking Fluoxetine compared to those on placebo.
Pediatric (children and adolescents):
The efficacy of Fluoxetine 20 mg/day for the treatment of major depressive disorder in pediatric outpatients (N=315 randomized; 170 children ages 8 to <13, 145 adolescents ages 13 to ≤18) has been studied in two 8- to 9-week placebo-controlled clinical trials.
In both studies independently, Fluoxetine produced a statistically significantly greater mean change on the Childhood Depression Rating Scale-Revised (CDRS-R) total score from baseline to endpoint than did placebo.
Subgroup analyses on the CDRS-R total score did not suggest any differential responsiveness on the basis of age or gender.
Obsessive Compulsive Disorder:
Adult:
The effectiveness of Fluoxetine for the treatment for obsessive compulsive disorder (OCD) was demonstrated in two 13-week, multicenter, parallel group studies (Studies 1 and 2) of adult outpatients who received fixed Fluoxetine doses of 20, 40, or 60 mg/day (on a once a day schedule, in the morning) or placebo. Patients in both studies had moderate to severe OCD (DSM-III-R), with mean baseline ratings on the Yale-Brown Obsessive Compulsive Scale (YBOCS, total score) ranging from 22 to 26. In Study 1, patients receiving Fluoxetine experienced mean reductions of approximately 4 to 6 units on the YBOCS total score, compared to a 1-unit reduction for placebo patients. In Study 2, patients receiving Fluoxetine experienced mean reductions of approximately 4 to 9 units on the YBOCS total score, compared to a 1-unit reduction for placebo patients. While there was no indication of a dose response relationship for effectiveness in Study 1, a dose response relationship was observed in Study 2, with numerically better responses in the two higher dose groups. The following table provides the outcome classification by treatment group on the Clinical Global Impression (CGI) improvement scale for Studies 1 and 2 combined:
Outcome Classification (%) on CGI Improvement Scale for Completers in Pool of Two OCD Studies
| Fluoxetine |
| Outcome Classification |
Placebo |
20 mg |
40 mg |
60 mg |
| Worse |
8% |
0% |
0% |
0% |
| No Change |
64% |
41% |
33% |
29% |
| Minimally Improved |
17% |
23% |
28% |
24% |
| Much Improved |
8% |
28% |
27% |
28% |
| Very Much Improved |
3% |
8% |
12% |
19% |
Exploratory analyses for age and gender effects on outcome did not suggest any differential responsiveness on the basis of age or sex.
Pediatric (children and adolescents):
In one 13-week clinical trial in pediatric patients (N=103 randomized; 75 children ages 7 to <13, 28 adolescents ages 13 to <18) with OCD, patients received Fluoxetine 10 mg/day for 2 weeks, followed by 20 mg/day for 2 weeks. The dose was then adjusted in the range of 20 to 60 mg/day on the basis of clinical response and tolerability. Fluoxetine produced a statistically significantly greater mean change from baseline to endpoint than did placebo as measured by the Children’s Yale-Brown Obsessive Compulsive Scale (CY-BOCS).
Subgroup analyses on outcome did not suggest any differential responsiveness on the basis of age or gender.
Bulimia Nervosa:
The effectiveness of Fluoxetine for the treatment of bulimia was demonstrated in two 8-week and one 16-week, multicenter, parallel group studies of adult outpatients meeting DSM-III-R criteria for bulimia. Patients in the 8-week studies received either 20 or 60 mg/day of Fluoxetine or placebo in the morning. Patients in the 16-week study received a fixed Fluoxetine dose of 60 mg/day (once a day) or placebo. Patients in these three studies had moderate to severe bulimia with median binge-eating and vomiting frequencies ranging from 7 to 10 per week and 5 to 9 per week, respectively. In these three studies, Fluoxetine 60 mg, but not 20 mg, was statistically significantly superior to placebo in reducing the number of binge-eating and vomiting episodes per week. The statistically significantly superior effect of 60 mg vs placebo was present as early as Week 1 and persisted throughout each study. The Fluoxetine related reduction in bulimic episodes appeared to be independent of baseline depression as assessed by the Hamilton Depression Rating Scale. In each of these 3 studies, the treatment effect, as measured by differences between Fluoxetine 60 mg, and placebo on median reduction from baseline in frequency of bulimic behaviors at endpoint, ranged from 1 to 2 episodes per week for binge-eating and 2 to 4 episodes per week for vomiting. The size of the effect was related to baseline frequency, with greater reductions seen in patients with higher baseline frequencies. Although some patients achieved freedom from binge-eating and purging as a result of treatment, for the majority, the benefit was a partial reduction in the frequency of binge-eating and purging.
In a longer-term trial, 150 patients meeting DSM-IV criteria for bulimia nervosa, purging subtype, who had responded during a single-blind, 8-week acute treatment phase with Fluoxetine 60 mg/day, were randomized to continuation of Fluoxetine 60 mg/day or placebo, for up to 52 weeks of observation for relapse. Response during the single-blind phase was defined by having achieved at least a 50% decrease in vomiting frequency compared with baseline. Relapse during the double-blind phase was defined as a persistent return to baseline vomiting frequency or physician judgement that the patient had relapsed. Patients receiving continued Fluoxetine 60 mg/day experienced a significantly longer time to relapse over the subsequent 52 weeks compared with those receiving placebo.
Panic Disorder:
The effectiveness of Fluoxetine in the treatment of panic disorder was demonstrated in 2 double-blind, randomized, placebo-controlled, multi-center studies of adult outpatients who had a primary diagnosis of panic disorder (DSM-IV), with or without agoraphobia.
Study 1 (N=180 randomized) was a 12-week flexible-dose study. Fluoxetine was initiated at 10 mg/day for the first week, after which patients were dosed in the range of 20 to 60 mg/day on
the basis of clinical response and tolerability. A statistically significantly greater percentage of
Fluoxetine-treated patients were free from panic attacks at endpoint than placebo-treated patients,
42% versus 28%, respectively.
Study 2 (N=214 randomized) was a 12-week flexible-dose study. Fluoxetine was initiated at
10 mg/day for the first week, after which patients were dosed in a range of 20 to 60 mg/day on
the basis of clinical response and tolerability. A statistically significantly greater percentage of
Fluoxetine-treated patients were free from panic attacks at endpoint than placebo-treated patients,
62% versus 44%, respectively.
INDICATIONS AND USAGE:
Major Depressive Disorder:
Fluoxetine is indicated for the treatment of major depressive disorder.
Adult:
The efficacy of Fluoxetine was established in 5- and 6-week trials with depressed adult and geriatric outpatients (≥ 18 years of age) whose diagnoses corresponded most closely to the DSM-III (currently DSM-IV) category of major depressive disorder (see CLINICAL TRIALS).
A major depressive episode (DSM-IV) implies a prominent and relatively persistent (nearly every day for at least 2 weeks) depressed or dysphoric mood that usually interferes with daily functioning, and includes at least five of the following nine symptoms: depressed mood; loss of interest in usual activities; significant change in weight and/or appetite; insomnia or hypersomnia; psychomotor agitation or retardation; increased fatigue; feelings of guilt or worthlessness; slowed thinking or impaired concentration; a suicide attempt or suicidal ideation.
The effects of Fluoxetine in hospitalized depressed patients have not been adequately studied.
The efficacy of Fluoxetine 20 mg once-daily in maintaining a response in major depressive disorder for up to 38 weeks following 12 weeks of open-label acute treatment (50 weeks total) was demonstrated in a placebo-controlled trial.
Pediatric (children and adolescents):
The efficacy of Fluoxetine in children and adolescents was established in two 8- to 9-week placebo-controlled clinical trials in depressed outpatients whose diagnoses corresponded most closely to the DSM-III-R or DSM-IV category of major depressive
disorder (see CLINICAL TRIALS).
The usefulness of the drug in adult and pediatric patients receiving Fluoxetine for extended periods should be reevaluated periodically.
Obsessive-Compulsive Disorder:
Adult:
Fluoxetine is indicated for the treatment of obsessions and compulsions in patients with obsessive-compulsive disorder (OCD), as defined in the DSM-III-R; i.e., the obsessions or compulsions cause marked distress, are time-consuming, or significantly interfere with social or occupational functioning.
The efficacy of Fluoxetine was established in 13-week trials with obsessive-compulsive outpatients whose diagnoses corresponded most closely to the DSM-III-R category of obsessive-compulsive disorder (see CLINICAL TRIALS).
OCD is characterized by recurrent and persistent ideas, thoughts, impulses, or images (obsessions) that are ego-dystonic and/or repetitive, purposeful, and intentional behaviors (compulsions) that are recognized by the person as excessive or unreasonable.
The effectiveness of Fluoxetine in long-term use, i.e., for more than 13 weeks, has not been systematically evaluated in placebo-controlled trials. Therefore, the physician who elects to use Fluoxetine for extended periods should periodically reevaluate the long-term usefulness of the drug for the individual patient (see DOSAGE AND ADMINISTRATION).
Pediatric (children and adolescents):
The efficacy of Fluoxetine in children and adolescents was
established in a 13-week, dose titration, clinical trial in patients with OCD, as defined in
DSM-IV (see CLINICAL TRIALS).
Bulimia Nervosa:
Fluoxetine is indicated for the treatment of binge-eating and vomiting behaviors in patients with moderate to severe bulimia nervosa.
The efficacy of Fluoxetine was established in 8 to 16 week trials for adult outpatients with moderate to severe bulimia nervosa, i.e., at least three bulimic episodes per week for 6 months (see CLINICAL TRIALS).
The efficacy of Fluoxetine 60 mg/day in maintaining a response, in patients with bulimia who responded during an 8-week acute treatment phase while taking Fluoxetine 60 mg/day and were then observed for relapse during a period of up to 52 weeks, was demonstrated in a placebo-controlled trial (see CLINICAL TRIALS). Nevertheless, the physician who elects to use Fluoxetine for extended periods should periodically reevaluate the long-term usefulness of the drug for the individual patient (see DOSAGE AND ADMINISTRATION).
Panic Disorder:
Fluoxetine is indicated for the treatment of panic disorder, with or without agoraphobia, as defined in DSM-IV. Panic disorder is characterized by the occurrence of unexpected panic attacks, and associated concern about having additional attacks, worry about the implications or consequences of the attacks, and/or a significant change in behavior related to the attacks.
The efficacy of Fluoxetine was established in two 12-week clinical trials in patients whose diagnoses corresponded to the DSM-IV category of panic disorder (see CLINICAL TRIALS).
Panic disorder (DSM-IV) is characterized by recurrent, unexpected panic attacks, i.e., a discrete period of intense fear or discomfort in which 4 or more of the following symptoms develop abruptly and reach a peak within 10 minutes: 1) palpitations, pounding heart, or accelerated heart rate; 2) sweating; 3) trembling or shaking; 4) sensations of shortness of breath or smothering; 5) feeling of choking; 6) chest pain or discomfort; 7) nausea or abdominal distress; 8) feeling dizzy, unsteady, lightheaded, or faint; 9) fear of losing control; 10) fear of dying; 11) paresthesias (numbness or tingling sensations); 12) chills or hot flashes.
The effectiveness of Fluoxetine in long-term use, i.e., for more than 12 weeks, has not been established in placebo-controlled trials. Therefore, the physician who elects to use Fluoxetine for extended periods should periodically reevaluate the long-term usefulness of the drug for the individual patient (see DOSAGE AND ADMINISTRATION).
CONTRAINDICATIONS:
Fluoxetine hydrochloride is contraindicated in patients known to be hypersensitive to it.
Monoamine Oxidase Inhibitors:
There have been reports of serious, sometimes fatal, reactions (including hyperthermia, rigidity, myoclonus, autonomic instability with possible rapid fluctuations of vital signs, and mental status changes that include extreme agitation progressing to delirium and coma) in patients receiving Fluoxetine in combination with a monoamine oxidase inhibitor (MAOI), and in patients who have recently discontinued Fluoxetine and are then started on an MAOI. Some cases presented with features resembling neuroleptic malignant syndrome. Therefore, Fluoxetine should not be used in combination with an MAOI, or within a minimum of 14 days of discontinuing therapy with an MAOI. Since Fluoxetine and its major metabolite have very long elimination half-lives, at least 5 weeks (perhaps longer, especially if Fluoxetine has been prescribed chronically and/or at higher doses [see Accumulation and Slow Elimination under CLINICAL PHARMACOLOGY]) should be allowed after stopping Fluoxetine before starting an MAOI.
Pimozide:
Concomitant use in patients taking pimozide is contraindicated (see PRECAUTIONS).
Thioridazine:
Thioridazine should not be administered with Fluoxetine or within a minimum of 5 weeks after Fluoxetine has been discontinued (see WARNINGS).
WARNINGS:
Clinical Worsening and Suicide Risk:
Patients with major depressive disorder (MDD), both adult and pediatric, may experience worsening of their depression and/or the emergence of suicidal ideation and behavior (suicidality) or unusual changes in behavior, whether or not they are taking antidepressant medications, and this risk may persist until significant remission occurs. Suicide is a known risk of depression and certain other psychiatric disorders, and these disorders themselves are the strongest predictors of suicide. There has been a long-standing concern, however, that antidepressants may have a role in inducing worsening of depression and the emergence of suicidality in certain patients during the early phases of treatment. Pooled analyses of short-term placebo-controlled trials of antidepressant drugs (SSRIs and others) showed that these drugs increase the risk of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults (ages 18-24) with major depressive disorder (MDD) and other psychiatric disorders. Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24; there was a reduction with antidepressants compared to placebo in adults aged 65 and older.
The pooled analyses of placebo-controlled trials in children and adolescents with MDD, obsessive compulsive disorder (OCD), or other psychiatric disorders included a total of 24 short-term trials of 9 antidepressant drugs in over 4400 patients. The pooled analyses of placebo-controlled trials in adults with MDD or other psychiatric disorders included a total of 295 short-term trials (median duration of 2 months) of 11 antidepressant drugs in over 77,000 patients. There was considerable variation in risk of suicidality among drugs, but a tendency toward an increase in the younger patients for almost all drugs studied. There were differences in absolute risk of suicidality across the different indications, with the highest incidence in MDD. The risk differences (drug vs placebo), however, were relatively stable within age strata and across indications. These risk differences (drug-placebo difference in the number of cases of suicidality per 1000 patients treated) are provided in Table 1.
| Table 1 |
| Age Range |
Drug-Placebo Difference in
Number of Cases of Suicidality per 1000 Patients Treated |
| Drug-Related Increases |
| <18 |
14 additional cases |
| 18-24 |
5 additional cases |
| Drug-Related Decreases |
| 25-64 |
1 fewer case |
|
>65 |
6 fewer cases |
No suicides occurred in any of the pediatric trials. There were suicides in the adult trials, but the number was not sufficient to reach any conclusion about drug effect on suicide.
It is unknown whether the suicidality risk extends to longer-term use, i.e., beyond several months. However, there is substantial evidence from placebo-controlled maintenance trials in adults with depression that the use of antidepressants can delay the recurrence of depression.
All patients being treated with antidepressants for any indication should be monitored appropriately and observed closely for clinical worsening, suicidality, and unusual changes in behavior, especially during the initial few months of a course of drug therapy, or at times of dose changes, either increases or decreases.
The following symptoms, anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania, and mania, have been reported in adult and pediatric patients being treated with antidepressants for major depressive disorder as well as for other indications, both psychiatric and nonpsychiatric. Although a causal link between the emergence of such symptoms and either the worsening of depression and/or the emergence of suicidal impulses has not been established, there is concern that such symptoms may represent precursors to emerging suicidality.
Consideration should be given to changing the therapeutic regimen, including possibly discontinuing the medication, in patients whose depression is persistently worse, or who are experiencing emergent suicidality or symptoms that might be precursors to worsening depression or suicidality, especially if these symptoms are severe, abrupt in onset, or were not part of the patient's presenting symptoms.
If the decision has been made to discontinue treatment, medication should be tapered, as rapidly as is feasible, but with recognition that abrupt discontinuation can be associated with certain symptoms (see PRECAUTIONS and DOSAGE AND ADMINISTRATION-Discontinuation of Treatment with Fluoxetine Capsules, for a description of the risks of discontinuation of Fluoxetine capsules).
Families and caregivers of patients being treated with antidepressants for major depressive disorder or other indications, both psychiatric and nonpsychiatric, should be alerted about the need to monitor patients for the emergence of agitation, irritability, unusual changes in behavior, and the other symptoms described above, as well as the emergence of suicidality, and to report such symptoms immediately to healthcare providers. Such monitoring should include daily observation by families and caregivers. Prescriptions for Fluoxetine should be written for the smallest quantity of capsules consistent with good patient management, in order to reduce the risk of overdose.
Screening Patients for Bipolar Disorder:
A major depressive episode may be the initial presentation of bipolar disorder. It is generally believed (though not established in controlled trials) that treating such an episode with an antidepressant alone may increase the likelihood of precipitation of a mixed/manic episode in patients at risk for bipolar disorder. Whether any of the symptoms described above represent such a conversion is unknown. However, prior to initiating treatment with an antidepressant, patients with depressive symptoms should be adequately screened to determine if they are at risk for bipolar disorder; such screening should include a detailed psychiatric history, including a family history of suicide, bipolar disorder, and depression. It should be noted that Fluoxetine is not approved for use in treating bipolar depression.
Rash and Possibly Allergic Events:
In U.S. Fluoxetine clinical trials as of May 8, 1995, 7% of 10,782 patients developed various types of rashes and/or urticaria. Among the cases of rash and/or urticaria reported in premarketing clinical trials, almost a third were withdrawn from treatment because of the rash and/or systemic signs or symptoms associated with the rash. Clinical findings reported in association with rash include fever, leukocytosis, arthralgias, edema, carpal tunnel syndrome, respiratory distress, lymphadenopathy, proteinuria, and mild transaminase elevation. Most patients improved promptly with discontinuation of Fluoxetine and/or adjunctive treatment with antihistamines or steroids, and all patients experiencing these events were reported to recover completely.
In premarketing clinical trials, 2 patients are known to have developed a serious cutaneous systemic illness. In neither patient was there an unequivocal diagnosis, but one was considered to have a leukocytoclastic vasculitis, and the other, a severe desquamating syndrome that was considered variously to be a vasculitis or erythema multiforme. Other patients have had systemic syndromes suggestive of serum sickness.
Since the introduction of Fluoxetine, systemic events, possibly related to vasculitis and including lupus-like syndrome, have developed in patients with rash. Although these events are rare, they may be serious, involving the lung, kidney, or liver. Death has been reported to occur in association with these systemic events.
Anaphylactoid events, including bronchospasm, angioedema, laryngospasm, and urticaria alone and in combination, have been reported.
Pulmonary events, including inflammatory processes of varying histopathology and/or fibrosis, have been reported rarely. These events have occurred with dyspnea as the only preceding symptom.
Whether these systemic events and rash have a common underlying cause or are due to different etiologies or pathogenic processes is not known. Furthermore, a specific underlying immunologic basis for these events has not been identified. Upon the appearance of rash or of other possibly allergic phenomena for which an alternative etiology cannot be identified, Fluoxetine should be discontinued.
Serotonin Syndrome:
The development of a potentially life-threatening serotonin syndrome may occur with Fluoxetine treatment, particularly with concomitant use of serotonergic drugs (including triptans) and with drugs which impair metabolism of serotonin (including MAOIs). Serotonin syndrome symptoms may include mental status changes (e.g., agitation, hallucinations, coma), autonomic instability (e.g., tachycardia, labile blood pressure, hyperthermia), neuromuscular aberrations (e.g., hyperreflexia, incoordination) and/or gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea).
The concomitant use of Fluoxetine with MAOIs intended to treat depression is contraindicated
(see CONTRAINDICATIONS and Drug Interactions under PRECAUTIONS).
If concomitant treatment of Fluoxetine with a 5-hydroxytryptamine receptor agonist (triptan) is
clinically warranted, careful observation of the patient is advised, particularly during treatment
initiation and dose increases (see Drug Interactions under PRECAUTIONS).
The concomitant use of Fluoxetine with serotonin precursors (such as tryptophan) is not recommended (see Drug Interactions under PRECAUTIONS).
Potential Interaction with Thioridazine:
In a study of 19 healthy male subjects, which included 6 slow and 13 rapid hydroxylators of debrisoquin, a single 25-mg oral dose of thioridazine produced a 2.4-fold higher Cmax and a 4.5-fold higher AUC for thioridazine in the slow hydroxylators compared to the rapid hydroxylators. The rate of debrisoquin hydroxylation is felt to depend on the level of cytochrome CYP2D6 isozyme activity. Thus, this study suggests that drugs which inhibit CYP2D6, such as certain SSRIs, including Fluoxetine, will produce elevated plasma levels of thioridazine (see PRECAUTIONS).
Thioridazine administration produces a dose-related prolongation of the QTc interval, which is associated with serious ventricular arrhythmias, such as torsades de pointes-type arrhythmias, and sudden death. This risk is expected to increase with Fluoxetine-induced inhibition of thioridazine metabolism (see CONTRAINDICATIONS).
PRECAUTIONS:
General:
Abnormal Bleeding:
Published case reports have documented the occurrence of bleeding episodes in patients treated with psychotropic drugs that interfere with serotonin reuptake. Subsequent epidemiological studies, both of the case control and cohort design, have demonstrated an association between use of psychotropic drugs that interfere with serotonin reuptake and the occurrence of upper gastrointestinal bleeding. In two studies, concurrent use of a nonsteroidal anti-inflammatory drug (NSAID) or aspirin potentiated the risk of bleeding (see Drug Interactions). Although these studies focused on upper gastrointestinal bleeding, there is reason to believe that bleeding at other sites may be similarly potentiated. Patients should be cautioned regarding the risk of bleeding associated with the concomitant use of Fluoxetine with NSAIDs, aspirin, or other drugs that affect coagulation.
Anxiety and Insomnia:
In U.S. placebo-controlled clinical trials for major depressive disorder, 12% to 16% of patients treated with Fluoxetine and 7% to 9% of patients treated with placebo reported anxiety, nervousness, or insomnia.
In U.S. placebo-controlled clinical trials for OCD, insomnia was reported in 28% of patients treated with Fluoxetine and in 22% of patients treated with placebo. Anxiety was reported in 14% of patients treated with Fluoxetine and in 7% of patients treated with placebo.
In U.S. placebo-controlled clinical trials for bulimia nervosa, insomnia was reported in 33% of patients treated with Fluoxetine 60 mg, and 13% of patients treated with placebo. Anxiety and nervousness were reported respectively in 15% and 11% of patients treated with Fluoxetine 60 mg, and in 9% and 5% of patients treated with placebo.
Among the most common adverse events associated with discontinuation (incidence at least twice that for placebo and at least 1% for Fluoxetine in clinical trials collecting only a primary event associated with discontinuation) in U.S. placebo-controlled Fluoxetine clinical trials were anxiety (2% in OCD), insomnia (15 in combined indications and 2% in bulimia), and nervousness (1% in major depressive disorder) (see Table3).
Altered Appetite and Weight:
Significant weight loss, especially in underweight depressed or bulimic patients may be an undesirable result of treatment with Fluoxetine.
In U.S. placebo-controlled clinical trials for major depressive disorder, 11% of patients treated with Fluoxetine and 2% of patients treated with placebo reported anorexia (decreased appetite). Weight loss was reported in 1.4% of patients treated with Fluoxetine and in 0.5% of patients treated with placebo. However, only rarely have patients discontinued treatment with Fluoxetine because of anorexia or weight loss (see also Pediatric Use under PRECAUTIONS).
In U.S. placebo-controlled clinical trials for OCD, 17% of patients treated with Fluoxetine and 10% of patients treated with placebo reported anorexia (decreased appetite). One patient discontinued treatment with Fluoxetine because of anorexia (see also Pediatric Use under PRECAUTIONS).
In U.S. placebo-controlled clinical trials for bulimia nervosa, 8% of patients treated with Fluoxetine, 60 mg, and 4% of patients treated with placebo reported anorexia (decreased appetite). Patients treated with Fluoxetine, 60 mg, on average lost 0.45 kg compared with a gain of 0.16 kg by patients treated with placebo in the 16-week double-blind trial. Weight change should be monitored during therapy.
Activation of Mania/Hypomania:
In U.S. placebo-controlled clinical trials for major depressive disorder, mania/hypomania was reported in 0.1% of patients treated with Fluoxetine and 0.1% of patients treated with placebo. Activation of mania/hypomania has also been reported in a small proportion of patients with Major Affective Disorder treated with other marketed drugs effective in the treatment of major depressive disorder (see also Pediatric Use under PRECAUTIONS).
In U.S. placebo-controlled clinical trials for OCD, mania/hypomania was reported in 0.8% of patients treated with Fluoxetine and no patients treated with placebo. No patients reported mania/hypomania in U.S. placebo-controlled clinical trials for bulimia. In all U.S. Fluoxetine clinical trials as of May 8, 1995, 0.7% of 10,782 patients reported mania/hypomania (see also Pediatric Use under PRECAUTIONS).
Hyponatremia:
Cases of hyponatremia (some with serum sodium lower than 110 mmol/L) have been reported. The hyponatremia appeared to be reversible when Fluoxetine was discontinued. Although these cases were complex with varying possible etiologies, some were possibly due to the syndrome of inappropriate antidiuretic hormone secretion (SIADH). The majority of these occurrences have been in older patients and in patients taking diuretics or who were otherwise volume depleted. In two 6-week controlled studies in patients ≥ 60 years of age, 10 of 323 Fluoxetine patients and 6 of 327 placebo recipients had a lowering of serum sodium below the reference range; this difference was not statistically significant. The lowest observed concentration was 129 mmol/L. The observed decreases were not clinically significant.
Seizures:
In U.S. placebo-controlled clinical trials for major depressive disorder, convulsions (or events described as possibly having been seizures) were reported in 0.1% of patients treated with Fluoxetine and 0.2% of patients treated with placebo. No patients reported convulsions in U.S. placebo-controlled clinical trials for either OCD or bulimia. In all U.S. Fluoxetine clinical trials as of May 8, 1995, 0.2% of 10,782 patients reported convulsions. The percentage appears to be similar to that associated with other marketed drugs effective in the treatment of major depressive disorder. Fluoxetine should be introduced with care in patients with a history of seizures.
The Long Elimination Half-Lives of Fluoxetine and Its Metabolites:
Because of the long elimination half-lives of the parent drug and its major active metabolite, changes in dose will not be fully reflected in plasma for several weeks, affecting both strategies for titration to final dose and withdrawal from treatment (see CLINICAL PHARMACOLOGY and DOSAGE AND ADMINISTRATION).
Use in Patients with Concomitant Illness:
Clinical experience with Fluoxetine in patients with concomitant systemic illness is limited. Caution is advisable in using Fluoxetine in patients with diseases or conditions that could affect metabolism or hemodynamic responses.
Fluoxetine has not been evaluated or used to any appreciable extent in patients with a recent history of myocardial infarction or unstable heart disease. Patients with these diagnoses were systematically excluded from clinical studies during the product’s premarket testing. However, the electrocardiograms of 312 patients who received Fluoxetine in double-blind trials were retrospectively evaluated; no conduction abnormalities that resulted in heart block were observed. The mean heart rate was reduced by approximately 3 beats/min.
In subjects with cirrhosis of the liver, the clearances of Fluoxetine and its active metabolite, norFluoxetine, were decreased, thus increasing the elimination half-lives of these substances. A lower or less frequent dose should be used in patients with cirrhosis.
Studies in depressed patients on dialysis did not reveal excessive accumulation of Fluoxetine or norFluoxetine in plasma (see Renal Disease under CLINICAL PHARMACOLOGY). Use of a lower or less frequent dose for renally impaired patients is not routinely necessary (see DOSAGE AND ADMINISTRATION).
In patients with diabetes, Fluoxetine may alter glycemic control. Hypoglycemia has occurred during therapy with Fluoxetine, and hyperglycemia has developed following discontinuation of the drug. As is true with many other types of medication when taken concurrently by patients with diabetes, insulin and/or oral hypoglycemic dosage may need to be adjusted when therapy with Fluoxetine is instituted or discontinued.
Interference with Cognitive and Motor Performance:
Any psychoactive drug may impair judgment, thinking, or motor skills, and patients should be cautioned about operating hazardous machinery, including automobiles, until they are reasonably certain that the drug treatment does not affect them adversely.
Discontinuation of Treatment with Fluoxetine:
During marketing of Fluoxetine and other SSRIs and SNRIs (serotonin and norepinephrine reuptake inhibitors), there have been spontaneous reports of adverse events occurring upon discontinuation of these drugs, particularly when abrupt, including the following: dysphoric mood, irritability, agitation, dizziness, sensory disturbances (e.g., paresthesias such as electric shock sensations), anxiety, confusion, headache, lethargy, emotional lability, insomnia, and hypomania. While these events are generally self-limiting, there have been reports of serious discontinuation symptoms. Patients should be monitored for these symptoms when discontinuing treatment with Fluoxetine. A gradual reduction in the dose rather than abrupt cessation is recommended whenever possible. If intolerable symptoms occur following a decrease in the dose or upon discontinuation of treatment, then resuming the previously prescribed dose may be considered. Subsequently, the physician may continue decreasing the dose but at a more gradual rate. Plasma Fluoxetine and norFluoxetine concentration decrease gradually at the conclusion of therapy, which may minimize the risk of discontinuation symptoms with this drug (see DOSAGE AND ADMINISTRATION).
Information for Patients:
Prescribers or other health professionals should inform patients, their families, and their caregivers about the benefits and risks associated with treatment with Fluoxetine and should counsel them in its appropriate use. A patient Medication Guide about “Antidepressant Medicines, Depression and other Serious Mental Illness, and Suicidal Thoughts or Actions” is available for Fluoxetine. The prescriber or health professional should instruct patients, their families, and their caregivers to read the Medication Guide and should assist them in understanding its contents. Patients should be given the opportunity to discuss the contents of the Medication Guide and to obtain answers to any questions they may have. The complete text of the Medication Guide is reprinted at the end of this document.
Patients should be advised of the following issues and asked to alert their prescriber if these occur while taking Fluoxetine.
Clinical Worsening and Suicide Risk:
Patients, their families, and their caregivers should be encouraged to be alert to the emergence of anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania, mania, other unusual changes in behavior, worsening of depression, and suicidal ideation, especially early during antidepressant treatment and when the dose is adjusted up or down. Families and caregivers of patients should be advised to look for the emergence of such symptoms on a day-to-day basis, since changes may be abrupt. Such symptoms should be reported to the patient's prescriber or health professional, especially if they are severe, abrupt in onset, or were not part of the patient's presenting symptoms. Symptoms such as these may be associated with an increased risk for suicidal thinking and behavior and indicate a need for very close monitoring and possibly changes in the medication.
Serotonin Syndrome:
Patients should be cautioned about the risk of serotonin syndrome with the concomitant use of Fluoxetine and triptans, tramadol or other serotonergic agents.
Because Fluoxetine may impair judgment, thinking, or motor skills, patients should be advised to avoid driving a car or operating hazardous machinery until they are reasonably certain that their performance is not affected.
Patients should be advised to inform their physician if they are taking or plan to take any prescription or over-the-counter drugs, or alcohol.
Patients should be cautioned about the concomitant use of Fluoxetine and NSAIDs, aspirin, or other drugs that affect coagulation since combined use of psychotropic drugs that interfere with serotonin reuptake and these agents have been associated with an increased risk of bleeding.
Patients should be advised to notify their physician if they become pregnant or intend to become pregnant during therapy.
Patients should be advised to notify their physician if they are breast-feeding an infant.
Patients should be advised to notify their physician if they develop a rash or hives.
Laboratory Tests:
There are no specific laboratory tests recommended.
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 (see Accumulation and Slow Elimination under CLINICAL PHARMACOLOGY).
Drugs Metabolized by CYP2D6:
Approximately 7% of the normal population has a genetic defect that leads to reduced levels of activity of the cytochrome P450 isoenzyme 2D6. Such individuals have been referred to as “poor metabolizers” of drugs such as debrisoquin, dextromethorphan, and TCAs. Many drugs, such as most drugs effective in the treatment of major depressive disorder, including Fluoxetine and other selective uptake inhibitors of serotonin, are metabolized by this isoenzyme; thus, both the pharmacokinetic properties and relative proportion of metabolites are altered in poor metabolizers. However, for Fluoxetine and its metabolite, the sum of the plasma concentrations of the 4 active enantiomers is comparable between poor and extensive metabolizers (see Variability in Metabolism under CLINICAL PHARMACOLOGY).
Fluoxetine, like other agents that are metabolized by CYP2D6, inhibits the activity of this isoenzyme, and thus may make normal metabolizers resemble poor metabolizers. Therapy with medications that are predominantly metabolized by the CYP2D6 system and that have a relatively narrow therapeutic index (see list below), should be initiated at the low end of the dose range if a patient is receiving Fluoxetine concurrently or has taken it in the previous 5 weeks. Thus, his/her dosing requirements resemble those of poor metabolizers. If Fluoxetine is added to the treatment regimen of a patient already receiving a drug metabolized by CYP2D6, the need for decreased dose of the original medication should be considered. Drugs with a narrow therapeutic index represent the greatest concern (e.g., flecainide, vinblastine, and TCAs). Due to the risk of serious
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