5 WARNINGS AND PRECAUTIONS
5.1 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 to 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 versus 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 2.
Table 2: Suicidality per 1000 Patients TreatedAge Range
| Drug-Placebo Difference in Number of Cases of Suicidality per 1000 Patients Treated
|
| Increases Compared to Placebo
|
less than 18
| 14 additional cases
|
18 to 24
| 5 additional cases
|
| Decreases Compared to Placebo
|
25 to 64
| 1 fewer case
|
greater than or equal to 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 Warnings and Precautions (
5.13)].
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 health care providers. Such monitoring should include daily observation by families and
caregivers. Prescriptions for fluoxetine capsules should be written for
the smallest quantity of capsules consistent with good patient management, in order to reduce the risk of overdose.
It should be noted that fluoxetine is approved in the pediatric population only for Major Depressive Disorder and Obsessive Compulsive Disorder.
5.2 Serotonin Syndrome or Neuroleptic Malignant Syndrome (NMS)-Like Reactions
The development of a potentially life-threatening serotonin syndrome or neuroleptic malignant syndrome (NMS)-like reactions have been reported with SNRIs and SSRIs alone, including fluoxetine treatment, but particularly with concomitant use of serotonergic drugs (including triptans) with drugs which impair metabolism of serotonin (including MAOIs), or with antipsychotics or other dopamine antagonists. 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).
Serotonin syndrome, in its most severe form can resemble neuroleptic malignant syndrome, which includes hyperthermia, muscle rigidity, autonomic instability with possible rapid fluctuation
of vital signs, and mental status changes. Patients should be monitored
for the emergence of serotonin syndrome or NMSlike signs and symptoms.
The concomitant use of fluoxetine with MAOIs intended to treat depression is contraindicated [see Contraindications (
4) and Drug Interactions (
7.1)].
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 (
7.4)].
The concomitant use of
fluoxetine with serotonin precursors (such as tryptophan) is not
recommended [see Drug Interactions (
7.3)].
Treatment with fluoxetine and any concomitant serotonergic or antidopaminergic agents, including antipsychotics, should be discontinued immediately if the above reactions occur, and supportive symptomatic treatment should be initiated.
5.3 Allergic Reactions and Rash
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 reactions 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 reactions, possibly related to vasculitis and including lupus-like syndrome, have developed
in patients with rash. Although these reactions are rare, they may be
serious, involving the lung, kidney, or liver. Death has been reported to occur in association with these systemic reactions. page 7 of 27
Anaphylactoid reactions, including bronchospasm, angioedema, laryngospasm, and urticaria alone and in combination, have been reported.
Pulmonary
reactions, including inflammatory processes of varying histopathology and/or fibrosis, have been reported rarely. These reactions have occurred with dyspnea as the only preceding symptom.
Whether these systemic reactions 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 reactions 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.
5.4 Screening Patients for Bipolar Disorder and Monitoring for Mania/Hypomania
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 for clinical worsening and suicide risk 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 capsules are not indicated for use in treating bipolar depression.
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 Use in Specific Populations (
8.4)].
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 Use in Specific Populations (
8.4)].
5.5 Seizures
In
U.S. placebo-controlled clinical trials for Major Depressive Disorder, convulsions (or reactions 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.
5.6 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 Use in Specific Populations (
8.4)].
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 Use in Specific Populations (
8.4)].
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.
5.7 Abnormal Bleeding
SNRIs
and SSRIs, including fluoxetine, may increase the risk of bleeding reactions. Concomitant use of aspirin, nonsteroidal antiinflammatory drugs, warfarin, and other anti-coagulants may add to this risk. Case reports and epidemiological studies (case-control and
cohort design) have demonstrated an association between use of drugs
that interfere with serotonin reuptake and the occurrence of
gastrointestinal bleeding. Bleeding reactions related to SNRIs and SSRIs use have ranged from ecchymoses, hematomas, epistaxis, and
petechiae to life-threatening hemorrhages. Patients should be cautioned
about the risk of bleeding associated with the concomitant use of fluoxetine and NSAIDs, aspirin, warfarin, or other drugs that affect coagulation [see Drug Interactions (
7.6)].
5.8 Hyponatremia
Hyponatremia has been reported during treatment with SNRIs and SSRIs, including fluoxetine. In many cases, this hyponatremia appears to be the result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Cases with serum sodium lower than 110 mmol/L have been reported and appeared to be reversible when fluoxetine was discontinued. Elderly patients may be at greater risk of developing hyponatremia with SNRIs and SSRIs. Also, patients
taking diuretics or who are otherwise volume depleted may be at
greater risk [see Use in Specific Populations (
8.5)]. Discontinuation
of fluoxetine should be considered in patients with symptomatic hyponatremia and appropriate medical intervention should be instituted.
Signs and symptoms of hyponatremia include headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness, which may lead to falls. More severe and/or acute cases have been associated with hallucination, syncope, seizure, coma, respiratory arrest, and death.
5.9 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 reactions associated with discontinuation (incidence at least twice that for placebo and at least 1% for
fluoxetine in clinical trials collecting only a primary reaction
associated with discontinuation) in U.S. placebo-controlled fluoxetine clinical trials were anxiety (2% in OCD), insomnia (2% in bulimia), and nervousness (1% in Major Depressive Disorder) [
see Table 5:].
5.10 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.
Cardiovascular
— 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.
Glycemic
Control — 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.
5.11 Potential for Cognitive and Motor Impairment
As
with any CNS-active drug, fluoxetine has the potential to impair
judgment, thinking, or motor skills. Patients should be cautioned about
operating hazardous machinery, including automobiles, until they are
reasonably certain that the drug treatment does not affect them adversely.
5.12 Long Elimination Half-Life
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. 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 [see Clinical Pharmacology (
12.3)].
5.13 Discontinuation of Treatment
During marketing of fluoxetine, SNRIs, and SSRIs, there have been spontaneous reports of adverse reactions 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 reactions 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.