General
Agitation and Insomnia
A substantial proportion of patients treated with WELLBUTRIN
experience some degree of increased restlessness, agitation, anxiety, and
insomnia, especially shortly after initiation of treatment. In clinical
studies, these symptoms were sometimes of sufficient magnitude to require
treatment with sedative/hypnotic drugs. In approximately 2% of patients,
symptoms were sufficiently severe to require discontinuation of treatment with
WELLBUTRIN.
Psychosis, Confusion, and Other Neuropsychiatric Phenomena
Depressed patients treated with WELLBUTRIN have been
reported to show a variety of neuropsychiatric signs and symptoms including
delusions, hallucinations, psychosis, concentration disturbance, paranoia, and
confusion. Because of the uncontrolled nature of many studies, it is impossible
to provide a precise estimate of the extent of risk imposed by treatment with
WELLBUTRIN. In several cases, neuropsychiatric phenomena abated upon dose
reduction and/or withdrawal of treatment.
Activation of Psychosis and/or Mania
Antidepressants can precipitate manic episodes in bipolar
disorder patients during the depressed phase of their illness and may activate
latent psychosis in other susceptible patients. WELLBUTRIN is expected to pose
similar risks.
Altered Appetite and Weight
A weight loss of greater than 5 lbs occurred in 28% of
patients receiving WELLBUTRIN. This incidence is approximately double that seen
in comparable patients treated with tricyclics or placebo. Furthermore, while
35% of patients receiving tricyclic antidepressants gained weight, only 9.4% of
patients treated with WELLBUTRIN did. Consequently, if weight loss is a major presenting
sign of a patient's depressive illness, the anorectic and/or weight reducing
potential of WELLBUTRIN should be considered.
Allergic Reactions
Anaphylactoid/anaphylactic reactions characterized by
symptoms such as pruritus, urticaria, angioedema, and dyspnea requiring medical
treatment have been reported in clinical trials with bupropion. In addition,
there have been rare spontaneous postmarketing reports of erythema multiforme,
Stevens-Johnson syndrome, and anaphylactic shock associated with bupropion. A
patient should stop taking WELLBUTRIN and consult a doctor if experiencing
allergic or anaphylactoid/anaphylactic reactions (e.g., skin rash, pruritus,
hives, chest pain, edema, and shortness of breath) during treatment.
Arthralgia, myalgia, and fever with rash and other symptoms
suggestive of delayed hypersensitivity have been reported in association with
bupropion. These symptoms may resemble serum sickness.
Cardiovascular Effects
In clinical practice, hypertension, in some cases severe,
requiring acute treatment, has been reported in patients receiving bupropion
alone and in combination with nicotine replacement therapy. These events have
been observed in both patients with and without evidence of preexisting
hypertension.
Data from a comparative study of the sustained-release
formulation of bupropion (ZYBAN® Sustained-Release Tablets), nicotine
transdermal system (NTS), the combination of sustained-release bupropion plus
NTS, and placebo as an aid to smoking cessation suggest a higher incidence of
treatment-emergent hypertension in patients treated with the combination of
sustained-release bupropion and NTS. In this study, 6.1% of patients treated
with the combination of sustained-release bupropion and NTS had
treatment-emergent hypertension compared to 2.5%, 1.6%, and 3.1% of patients
treated with sustained-release bupropion, NTS, and placebo, respectively. The
majority of these patients had evidence of preexisting hypertension. Three
patients (1.2%) treated with the combination of ZYBAN and NTS and 1 patient
(0.4%) treated with NTS had study medication discontinued due to hypertension
compared to none of the patients treated with ZYBAN or placebo. Monitoring of
blood pressure is recommended in patients who receive the combination of
bupropion and nicotine replacement.
There is no clinical experience establishing the safety of
WELLBUTRIN in patients with a recent history of myocardial infarction or
unstable heart disease. Therefore, care should be exercised if it is used in
these groups. Bupropion was well tolerated in depressed patients who had
previously developed orthostatic hypotension while receiving tricyclic
antidepressants and was also generally well tolerated in a group of 36
depressed inpatients with stable congestive heart failure (CHF). However,
bupropion was associated with a rise in supine blood pressure in the study of
patients with CHF, resulting in discontinuation of treatment in 2 patients for
exacerbation of baseline hypertension.
Hepatic Impairment
WELLBUTRIN should be used with extreme caution in patients
with severe hepatic cirrhosis. In these patients, a reduced dose and frequency
is required. WELLBUTRIN should be used with caution in patients with hepatic
impairment (including mild to-moderate hepatic cirrhosis) and a reduced
frequency and/or dose should be considered in patients with mild-to-moderate
hepatic cirrhosis.
All patients with hepatic impairment should be closely monitored for possible
adverse effects that could indicate high drug and metabolite levels (see CLINICAL
PHARMACOLOGY, WARNINGS, and DOSAGE AND ADMINISTRATION).
Renal Impairment
There is limited information on the pharmacokinetics of
bupropion in patients with renal impairment. An inter-study comparison between
normal subjects and patients with end-stage renal failure demonstrated that the
parent drug Cmax and AUC values were comparable in the 2 groups, whereas the
hydroxybupropion and threohydrobupropion metabolites had a 2.3- and 2.8-fold
increase, respectively, in AUC for patients with end-stage renal failure. A
second study, comparing normal subjects and patients with moderate-to-severe
renal impairment (GFR 30.9 ± 10.8 mL/min) showed that exposure to a single
150-mg dose of sustained-release bupropion was approximately 2-fold higher in
patients with impaired renal function while levels of the hydroxybupropion and
threo/erythrohydrobupropion (combined) metabolites were similar in the 2
groups. Bupropion is extensively metabolized in the liver to active
metabolites, which are further metabolized and subsequently excreted by the
kidneys. WELLBUTRIN should be used with caution in patients with renal
impairment and a reduced frequency and/or dose should be considered as
bupropion and the metabolites of bupropion may accumulate in such patients to a
greater extent than usual. The patient should be closely monitored for possible
adverse effects that could indicate high drug or metabolite levels.
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 WELLBUTRIN and should counsel them in its appropriate use. A patient Medication
Guide about “Antidepressant Medicines, Depression and Other Serious Mental
Illnesses, and Suicidal Thoughts or Actions,” “Quitting Smoking,
Quit-Smoking Medication, Changes in Thinking and Behavior, Depression, and Suicidal
Thoughts or Actions,” and What Other Important Information Should I Know
About WELLBUTRIN ?” is available for WELLBUTRIN. 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 WELLBUTRIN.
Clinical Worsening and Suicide Risk in Treating Psychiatric Disorders
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.
Neuropsychiatric Symptoms and Suicide Risk in Smoking Cessation Treatment
Although WELLBUTRIN is not indicated for smoking cessation
treatment, it contains the same active ingredient as ZYBAN which is approved
for this use. Patients should be informed that quitting smoking, with or
without ZYBAN, may be associated with nicotine withdrawal symptoms (including
depression or agitation), or exacerbation of pre-existing psychiatric illness.
Furthermore, some patients have experienced changes in mood (including
depression and mania), psychosis, hallucinations, paranoia, delusions,
homicidal ideation aggression, anxiety, and panic, as well as suicidal
ideation, suicide attempt, and completed suicide when attempting to quit
smoking while taking ZYBAN. If patients develop agitation, hostility, depressed
mood, or changes in thinking or behavior that are not typical for them, or if
patients develop suicidal ideation or behavior, they should be urged to report
these symptoms to their healthcare provider immediately.
Bupropion-Containing Products
Patients should be made aware that WELLBUTRIN contains the
same active ingredient found in ZYBAN, used as an aid to smoking cessation, and
that WELLBUTRIN should not be used in combination with ZYBAN or any other medications
that contain bupropion hydrochloride (such as WELLBUTRIN SR, the
sustained-release formulation and WELLBUTRIN XL, the extended-release
formulation).
Patients should be instructed to take WELLBUTRIN in equally
divided doses 3 or 4 times a day to minimize the risk of seizure.
Patients should be told that WELLBUTRIN should be
discontinued and not restarted if they experience a seizure while on treatment.
Patients should be told that any CNS-active drug like
WELLBUTRIN may impair their ability to perform tasks requiring judgment or
motor and cognitive skills. Consequently, until they are reasonably certain
that WELLBUTRIN does not adversely affect their performance, they should
refrain from driving an automobile or operating complex, hazardous machinery.
Patients should be told that the excessive use or abrupt
discontinuation of alcohol or sedatives (including benzodiazepines) may alter
the seizure threshold. Some patients have reported lower alcohol tolerance
during treatment with WELLBUTRIN. Patients should be advised that the
consumption of alcohol should be minimized or avoided.
Patients should be advised to inform their physicians if
they are taking or plan to take any prescription or over-the-counter drugs.
Concern is warranted because WELLBUTRIN and other drugs may affect each other's
metabolism.
Patients should be advised to notify their physicians if
they become pregnant or intend to become pregnant during therapy.
Laboratory Tests
There are no specific laboratory tests recommended.
Carcinogenesis, Mutagenesis, Impairment of Fertility
Lifetime carcinogenicity studies were performed in rats and
mice at doses up to 300 and 150 mg/kg/day, respectively. In the rat study there
was an increase in nodular proliferative lesions of the liver at doses of 100
to 300 mg/kg/day; lower doses were not tested. The question of whether or not
such lesions may be precursors of neoplasms of the liver is currently
unresolved. Similar liver lesions were not seen in the mouse study, and no
increase in malignant tumors of the liver and other organs was seen in either
study.
Bupropion produced a borderline positive response (2 to 3
times control mutation rate) in some strains in the Ames bacterial mutagenicity
test, and a high oral dose (300 mg/kg, but not 100 or 200 mg/kg) produced a low
incidence of chromosomal aberrations in rats. The relevance of these results in
estimating the risk of human exposure to therapeutic doses is unknown.
A fertility study was performed in rats; no evidence of
impairment of fertility was encountered at oral doses up to 300 mg/kg/day.
Pregnancy
Teratogenic Effects
Pregnancy Category C. In studies conducted in rats and rabbits,
bupropion was administered orally at doses up to 450 and 150 mg/kg/day, respectively
(approximately 11 and 7 times the MRHD, respectively, on a mg/m² basis),
during the period of organogenesis. No clear evidence of teratogenic activity
was found in either species; however, in rabbits, slightly increased incidences
of fetal malformations and skeletal variations were observed at the lowest dose
tested (25 mg/kg/day, approximately equal to the MRHD on a mg/m² basis)
and greater. Decreased fetal weights were seen at 50 mg/kg and greater.
When rats were administered bupropion at oral doses of up to
300 mg/kg/day (approximately 7 times the MRHD on a mg/m² basis) prior to mating
and throughout pregnancy and lactation, there were no apparent adverse effects
on offspring development.
One study has been conducted in pregnant women. This
retrospective, managed-care database study assessed the risk of congenital
malformations overall and cardiovascular malformations specifically, following
exposure to bupropion in the first trimester compared to the risk of these
malformations following exposure to other antidepressants in the first
trimester and bupropion outside of the first trimester. This study included
7,005 infants with antidepressant exposure during pregnancy, 1,213 of whom were
exposed to bupropion in the first trimester. The study showed no greater risk
for congenital malformations overall or cardiovascular malformations
specifically, following first trimester bupropion exposure compared to exposure
to all other antidepressants in the first trimester, or bupropion outside of
the first trimester. The results of this study have not been corroborated.
WELLBUTRIN should be used during pregnancy only if the potential benefit
justifies the potential risk to the fetus.
Labor and Delivery
The effect of WELLBUTRIN on labor and delivery in humans is
unknown.
Nursing Mothers
Like many other drugs, bupropion and its metabolites are
secreted in human milk. Because of the potential for serious adverse reactions
in nursing infants from WELLBUTRIN, a decision should be made whether to
discontinue nursing or to discontinue the drug, taking into account the
importance of the drug to 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 in Treating Psychiatric Disorders). Anyone considering
the use of WELLBUTRIN in a child or adolescent must balance the potential risks
with the clinical need.
Geriatric Use
Of the approximately 6,000 patients who participated in
clinical trials with bupropion sustained-release tablets (depression and
smoking cessation studies), 275 were 65 and over and 47 were 75 and over. In
addition, several hundred patients 65 and over participated in clinical trials
using the immediate-release formulation of bupropion (depression studies). 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.
A single-dose pharmacokinetic study demonstrated that the
disposition of bupropion and its metabolites in elderly subjects was similar to
that of younger subjects; however, another pharmacokinetic study, single and
multiple dose, has suggested that the elderly are at increased risk for
accumulation of bupropion and its metabolites (see CLINICAL PHARMACOLOGY).
Bupropion is extensively metabolized in the liver to active metabolites, which
are further metabolized and excreted by the kidneys. The risk of toxic reaction
to this drug may be greater in patients with impaired renal function. Because
elderly patients are more likely to have decreased renal function, care should
be taken in dose selection, and it may be useful to monitor renal function (see
PRECAUTIONS: Renal Impairment and DOSAGE AND ADMINISTRATION).
Last updated on RxList: 7/20/2009