GeneralDiscontinuation of Treatment with Celexa
During marketing of Celexa 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 Celexa. 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 (see DOSAGE AND ADMINISTRATION).
Abnormal Bleeding
SSRIs and SNRIs, including Lexapro, may increase the risk of
bleeding events. Concomitant use of aspirin, nonsteroidal anti-inflammatory
drugs, warfarin, and other anticoagulants may add to the 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 events related to SSRIs and
SNRIs 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 Lexapro and NSAIDs, aspirin, or other drugs that affect
coagulation.
Hyponatremia
Hyponatremia may occur as a result of treatment with SSRIs and
SNRIs, including Celexa. In many cases, this hyponatremia appears to be the
result of the syndrome of inappropriate antidiureic hormone secretion (SIADH),
and was reversible when Celexa was discontinued. Cases with serum sodium lower
than 110 mmol/L have been reported. Elderly patients may be at greater risk of
developing hyponatremia with SSRIs and SNRIs. Also, patients taking diuretics or
who are otherwise volume depleted may be at greater risk (see Geriatric Use). Discontinuation of Celexa 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. signs and symptoms associated with more severe and/or acute
cases have included hallucination, syncompe, seizure, coma, respiratory arrest,
and death.
Activation of Mania/Hypomania
In placebo-controlled trials of Celexa, some of which included
patients with bipolar disorder, activation of mania/hypomania was reported in
0.2% of 1063 patients treated with Celexa and in none of the 446 patients
treated with placebo. Activation of mania/hypomania has also been reported in a
small proportion of patients with major affective disorders treated with other
marketed antidepressants. As with all antidepressants, Celexa should be used
cautiously in patients with a history of mania.
Seizures
Although anticonvulsant effects of citalopram have been observed
in animal studies, Celexa has not been systematically evaluated in patients with
a seizure disorder. These patients were excluded from clinical studies during
the product's premarketing testing. In clinical trials of Celexa, seizures
occurred in 0.3% of patients treated with Celexa (a rate of one patient per 98
years of exposure) and 0.5% of patients treated with placebo (a rate of one
patient per 50 years of exposure). Like other antidepressants, Celexa should be
introduced with care in patients with a history of seizure disorder.
Interference with Cognitive and Motor
Performance
In studies in normal volunteers, Celexa in doses of 40 mg/day did
not produce impairment of intellectual function or psychomotor performance.
Because any psychoactive drug may impair judgment, thinking, or motor skills,
however, patients should be cautioned about operating hazardous machinery,
including automobiles, until they are reasonably certain that Celexa therapy
does not affect their ability to engage in such activities.
Use in Patients with Concomitant Illness
Clinical experience with Celexa in patients with certain
concomitant systemic illnesses is limited. Caution is advisable in using Celexa
in patients with diseases or conditions that produce altered metabolism or
hemodynamic responses.
Celexa has not been systematically evaluated in patients with a recent
history of myocardial infarction or unstable heart disease. Patients with these
diagnoses were generally excluded from clinical studies during the product's
premarketing testing. However, the electrocardiograms of 1116 patients who
received Celexa in clinical trials were evaluated and the data indicate that
Celexa is not associated with the development of clinically significant ECG
abnormalities.
In subjects with hepatic impairment, citalopram clearance was decreased and
plasma concentrations were increased. The use of Celexa in hepatically impaired
patients should be approached with caution and a lower maximum dosage is
recommended (see DOSAGE AND
ADMINISTRATION).
Because citalopram is extensively metabolized, excretion of unchanged drug in
urine is a minor route of elimination. Until adequate numbers of patients with
severe renal impairment have been evaluated during chronic treatment with
Celexa, however, it should be used with caution in such patients (see DOSAGE AND ADMINISTRATION).
Information for Patients
Physicians are advised to discuss the following issues with
patients for whom they prescribe Celexa.
Patients should be cautioned about the risk of serotonin syndrome with the
concomitant use of Celexa and triptans, tramadol or
other serotonergic agents.
Although in controlled studies Celexa has not been shown to impair
psychomotor performance, any psychoactive drug may impair judgment, thinking, or
motor skills, so patients should be cautioned about operating hazardous
machinery, including automobiles, until they are reasonably certain that Celexa
therapy does not affect their ability to engage in such activities.
Patients should be told that, although Celexa has not been shown in
experiments with normal subjects to increase the mental and motor skill
impairments caused by alcohol, the concomitant use of Celexa and alcohol in
depressed patients is not advised.
Patients should be advised to inform their physician if they are taking, or
plan to take, any prescription or over-the-counter drugs, as there is a
potential for interactions.
Patients should be cautioned about the concomitant use of Celexa and NSAIDs,
aspirin, warfarin, or other drugs that affect coagulation since combined use of
psychotropic drugs that interfere with serotonin reuptake and these agents has
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
breastfeeding an infant.
While patients may notice improvement with Celexa therapy in 1 to 4 weeks,
they should be advised to continue therapy as directed.
Prescribers or other health professionals should inform patients, their
families, and their caregivers about the benefits and risks associated with
treatment with Celexa 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 Celexa. 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 Celexa.
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.
Laboratory Tests
There are no specific laboratory tests recommended.
Drug Interactions
Serotonergic Drugs: Based on the
mechanism of action of SNRIs and SSRIs including Celexa, and the potential for
serotonin syndrome, caution is advised when Celexa is coadministered with other
drugs that may affect the serotonergic neurotransmitter systems, such as
triptans, linezolid (an antibiotic which is a reversible non-selective MAOI),
lithium, tramadol, or St. John's Wort (see WARNINGS-Serotonin Syndrome). The concomitant use of
Celexa with other SSRIs, SNRIs or tryptophan is not
recommended (see PRECAUTIONS - Drug
Interactions).
Triptans: There have been rare
postmarketing reports of serotonin syndrome with use of an SSRI and a triptan.
If concomitant treatment of Celexa with a triptan is clinically warranted,
careful observation of the patient is advised, particularly during treatment
initiation and dose increases (see WARNINGS -
Serotonin Syndrome ).
CNS Drugs - Given the primary CNS effects of citalopram, caution
should be used when it is taken in combination with other centrally acting
drugs.
Alcohol - Although citalopram did not potentiate the cognitive
and motor effects of alcohol in a clinical trial, as with other psychotropic
medications, the use of alcohol by depressed patients taking Celexa is not
recommended.
Monoamine Oxidase Inhibitors (MAOIs) - See CONTRAINDICATIONS and WARNINGS.
Drugs That Interfere With Hemostasis (NSAIDs, Aspirin, Warfarin,
etc.)- Serotonin release by platelets plays an important role in hemostasis.
Epidemiological studies of the case-control and cohort design that have
demonstrated an association between use of psychotropic drugs that interfere
with serotonin reuptake and the occurrence of upper gastrointestinal bleeding.
These studies have also shown that concurrent use of an NSAID or aspirin may
potentiate the risk of bleeding.
Altered anticoagulant effects, including increased bleeding, have been
reported when SSRIs and SNRIs are coadministered with warfarin. Patients
receiving warfarin therapy should be carefully monitored when Lexapro is
initiated or discontinued.
Cimetidine - In subjects who had received 21 days of 40 mg/day
Celexa, combined administration of 400 mg/day cimetidine for 8 days resulted in
an increase in citalopram AUC and Cmax of 43% and 39%,
respectively. The clinical significance of these findings is unknown.
Digoxin - In subjects who had received 21 days of 40 mg/day
Celexa, combined administration of Celexa and digoxin (single dose of 1 mg) did
not significantly affect the pharmacokinetics of either citalopram or
digoxin.
Lithium - Coadministration of Celexa (40 mg/day for 10 days) and
lithium (30 mmol/day for 5 days) had no significant effect on the
pharmacokinetics of citalopram or lithium. Nevertheless, plasma lithium levels
should be monitored with appropriate adjustment to the lithium dose in
accordance with standard clinical practice. Because lithium may enhance the
serotonergic effects of citalopram, caution should be exercised when Celexa and
lithium are coadministered.
Pimozide - In a controlled study, a single dose of pimozide 2 mg
co-administered with citalopram 40 mg given once daily for 11 days was
associated with a mean increase in QTc values of approximately 10 msec compared
to pimozide given alone. Citalopram did not alter the mean AUC or Cmax of pimozide. The mechanism of this pharmacodynamic
interaction is not known.
Theophylline - Combined administration of Celexa (40 mg/day for
21 days) and the CYP1A2 substrate theophylline (single dose of 300 mg) did not
affect the pharmacokinetics of theophylline. The effect of theophylline on the
pharmacokinetics of citalopram was not evaluated.
Sumatriptan - There have been rare postmarketing reports
describing patients with weakness, hyperreflexia, and incoordination following
the use of a SSRI and sumatriptan. If concomitant treatment with sumatriptan and
an SSRI (e.g., fluoxetine, fluvoxamine, paroxetine, sertraline, citalopram) is
clinically warranted, appropriate observation of the patient is advised.
Warfarin - Administration of 40 mg/day Celexa for 21 days did not
affect the pharmacokinetics of warfarin, a CYP3A4 substrate. Prothrombin time
was increased by 5%, the clinical significance of which is unknown.
Carbamazepine - Combined administration of Celexa (40 mg/day for
14 days) and carbamazepine (titrated to 400 mg/day for 35 days) did not
significantly affect the pharmacokinetics of carbamazepine, a CYP3A4 substrate.
Although trough citalopram plasma levels were unaffected, given the
enzyme-inducing properties of carbamazepine, the possibility that carbamazepine
might increase the clearance of citalopram should be considered if the two drugs
are coadministered.
Triazolam - Combined administration of Celexa (titrated to 40
mg/day for 28 days) and the CYP3A4 substrate triazolam (single dose of 0.25 mg)
did not significantly affect the pharmacokinetics of either citalopram or
triazolam.
Ketoconazole - Combined administration of Celexa (40 mg) and
ketoconazole (200 mg) decreased the Cmax and AUC of
ketoconazole by 21% and 10%, respectively, and did not significantly affect the
pharmacokinetics of citalopram.
CYP3A4 and 2C19 Inhibitors - In vitro
studies indicated that CYP3A4 and 2C19 are the primary enzymes involved in the
metabolism of citalopram. However, coadministration of citalopram (40 mg) and
ketoconazole (200 mg), a potent inhibitor of CYP3A4, did not significantly
affect the pharmacokinetics of citalopram. Because citalopram is metabolized by
multiple enzyme systems, inhibition of a single enzyme may not appreciably
decrease citalopram clearance.
Metoprolol - Administration of 40 mg/day Celexa for 22 days resulted in a
two-fold increase in the plasma levels of the beta-adrenergic blocker
metoprolol. Increased metoprolol plasma levels have been associated with
decreased cardioselectivity. Coadministration of Celexa and metoprolol had no
clinically significant effects on blood pressure or heart rate.
Imipramine and Other Tricyclic Antidepressants (TCAs) - In vitro studies suggest that citalopram is a relatively
weak inhibitor of CYP2D6. Coadministration of Celexa (40 mg/day for 10 days)
with the TCA imipramine (single dose of 100 mg), a substrate for CYP2D6, did not
significantly affect the plasma concentrations of imipramine or citalopram.
However, the concentration of the imipramine metabolite desipramine was
increased by approximately 50%. The clinical significance of the desipramine
change is unknown. Nevertheless, caution is indicated in the coadministration of
TCAs with Celexa.
Electroconvulsive Therapy (ECT) - There are no clinical studies
of the combined use of electroconvulsive therapy (ECT) and Celexa.
Carcinogenesis, Mutagenesis, Impairment of
FertilityCarcinogenesis
Citalopram was administered in the diet to NMRI/BOM strain mice
and COBS WI strain rats for 18 and 24 months, respectively. There was no
evidence for carcinogenicity of citalopram in mice receiving up to 240
mg/kg/day, which is equivalent to 20 times the maximum recommended human daily
dose (MRHD) of 60 mg on a surface area (mg/m2) basis.
There was an increased incidence of small intestine carcinoma in rats receiving
8 or 24 mg/kg/day, doses which are approximately 1.3 and 4 times the MRHD,
respectively, on a mg/m2 basis. A no-effect dose for this
finding was not established. The relevance of these findings to humans is
unknown.
Mutagenesis
Citalopram was mutagenic in the in
vitro bacterial reverse mutation assay (Ames test) in 2 of 5 bacterial
strains (Salmonella TA98 and TA1537) in the absence of metabolic activation. It
was clastogenic in the in vitro Chinese hamster lung
cell assay for chromosomal aberrations in the presence and absence of metabolic
activation. Citalopram was not mutagenic in the in
vitro mammalian forward gene mutation assay (HPRT) in mouse lymphoma
cells or in a coupled in vitro/in vivo unscheduled
DNA synthesis (UDS) assay in rat liver. It was not clastogenic in the in vitro chromosomal aberration assay in human lymphocytes
or in two in vivo mouse micronucleus assays.
Impairment of Fertility
When citalopram was administered orally to 16 male and 24 female
rats prior to and throughout mating and gestation at doses of 32, 48, and 72
mg/kg/day, mating was decreased at all doses, and fertility was decreased at
doses ≥ 32 mg/kg/day, approximately 5 times the MRHD of 60 mg/day on a body
surface area (mg/m2) basis. Gestation duration was
increased at 48 mg/kg/day, approximately 8 times the MRHD.
PregnancyPregnancy Category C
In animal reproduction studies, citalopram has been shown to have
adverse effects on embryo/fetal and postnatal development, including teratogenic
effects, when administered at doses greater than human therapeutic doses.
In two rat embryo/fetal development studies, oral administration of
citalopram (32, 56, or 112 mg/kg/day) to pregnant animals during the period of
organogenesis resulted in decreased embryo/fetal growth and survival and an
increased incidence of fetal abnormalities (including cardiovascular and
skeletal defects) at the high dose, which is approximately 18 times the MRHD of
60 mg/day on a body surface area (mg/m2) basis. This dose
was also associated with maternal toxicity (clinical signs, decreased body
weight gain). The developmental, no-effect dose of 56 mg/kg/day is approximately
9 times the MRHD on a mg/m2 basis. In a rabbit study, no
adverse effects on embryo/fetal development were observed at doses of up to 16
mg/kg/day, or approximately 5 times the MRHD on a mg/m2
basis. Thus, teratogenic effects were observed at a maternally toxic dose in the
rat and were not observed in the rabbit.
When female rats were treated with citalopram (4.8, 12.8, or 32 mg/kg/day)
from late gestation through weaning, increased offspring mortality during the
first 4 days after birth and persistent offspring growth retardation were
observed at the highest dose, which is approximately 5 times the MRHD on a
mg/m2 basis. The no-effect dose of 12.8 mg/kg/day is
approximately 2 times the MRHD on a mg/m2 basis. Similar
effects on offspring mortality and growth were seen when dams were treated
throughout gestation and early lactation at doses ≥ 24 mg/kg/day, approximately
4 times the MRHD on a mg/m2 basis. A no-effect dose was
not determined in that study.
There are no adequate and well-controlled studies in pregnant women;
therefore, citalopram should be used during pregnancy only if the potential
benefit justifies the potential risk to the fetus.
Pregnancy-Nonteratogenic Effects
Neonates exposed to Celexa and other SSRIs or SNRIs, late in the
third trimester, have developed complications requiring prolonged
hospitalization, respiratory support, and tube feeding. Such complications can
arise immediately upon delivery. Reported clinical findings have included
respiratory distress, cyanosis, apnea, seizures, temperature instability,
feeding difficulty, vomiting, hypoglycemia, hypotonia, hypertonia,
hyperreflexia, tremor, jitteriness, irritability, and constant crying. These
features are consistent with either a direct toxic effect of SSRIs and SNRIs or,
possibly, a drug discontinuation syndrome. It should be noted that, in some
cases, the clinical picture is consistent with serotonin syndrome (see WARNINGS).
Infants exposed to SSRIs in late pregnancy may have an increased risk for
persistent pulmonary hypertension of the newborn (PPHN). PPHN occurs in 1—2 per
1000 live births in the general population and is associated with substantial
neonatal morbidity and mortality. In a retrospective, case-control study of 377
women whose infants were born with PPHN and 836 women whose infants were born
healthy, the risk for developing PPHN was approximately six-fold higher for
infants exposed to SSRIs after the 20th week of gestation compared to infants
who had not been exposed to antidepressants during pregnancy. There is currently
no corroborative evidence regarding the risk for PPHN following exposure to
SSRIs in pregnancy; this is the first study that has investigated the potential
risk. The study did not include enough cases with exposure to individual SSRIs
to determine if all SSRIs posed similar levels of PPHN risk.
When treating a pregnant woman with Celexa during the third trimester, the
physician should carefully consider both the potential risks and benefits of
treatment (see DOSAGE AND
ADMINISTRATION). Physicians should note that in a prospective
longitudinal study of 201 women with a history of major depression who were
euthymic at the beginning of pregnancy, women who discontinued antidepressant
medication during pregnancy were more likely to experience a relapse of major
depression than women who continued antidepressant medication.
Labor and Delivery
The effect of Celexa on labor and delivery in humans is
unknown.
Nursing Mothers
As has been found to occur with many other drugs, citalopram is
excreted in human breast milk. There have been two reports of infants
experiencing excessive somnolence, decreased feeding, and weight loss in
association with breastfeeding from a citalopram-treated mother; in one case,
the infant was reported to recover completely upon discontinuation of citalopram
by its mother and in the second case, no follow-up information was available.
The decision whether to continue or discontinue either nursing or Celexa therapy
should take into account the risks of citalopram exposure for the infant and the
benefits of Celexa treatment for the mother.
Pediatric Use
Safety and effectiveness in the pediatric population have not
been established (see BOX WARNING and WARNINGS—Clinical Worsening and Suicide Risk). Two
placebo-controlled trials in 407 pediatric patients with MDD have been conducted
with Celexa, and the data were not sufficient to support a claim for use in
pediatric patients. Anyone considering the use of Celexa in a child or
adolescent must balance the potential risks with the clinical need.
Geriatric Use
Of 4422 patients in clinical studies of Celexa, 1357 were 60 and
over, 1034 were 65 and over, and 457 were 75 and over. No overall differences in
safety or effectiveness were observed between these subjects and younger
subjects, and other reported clinical experience has not identified differences
in responses between the elderly and younger patients, but greater sensitivity
of some older individuals cannot be ruled out. Most elderly patients treated
with Celexa in clinical trials received daily doses between 20 and 40 mg (see
DOSAGE AND ADMINISTRATION).
SSRIs and SNRIs, including Celexa, have been associated with cases of
clinically significant hyponatremia in elderly patients, who may be at greater
risk for this adverse event (see PRECAUTIONS,
Hyponatremia).
In two pharmacokinetic studies, citalopram AUC was increased by 23% and 30%,
respectively, in elderly subjects as compared to younger subjects, and its
half-life was increased by 30% and 50%, respectively (see CLINICAL PHARMACOLOGY).
20 mg/day is the recommended dose for most elderly patients (see DOSAGE AND ADMINISTRATION).