CHANTIX� (varenicline) is a prescription medicine to help adults 18 and over stop smoking. You may benefit from quit-smoking support programs and/or counseling during your quit attempt. It's possible that you might slip up and smoke while taking CHANTIX. If you do, you can stay on CHANTIX and keep trying to quit.
Some patients have reported changes in behavior, agitation, depressed mood, suicidal thoughts or actions when attempting to quit smoking while taking CHANTIX or after stopping CHANTIX. If either you, your family, or caregiver notice agitation, depressed mood, or changes in behavior that are not typical for you, or if you develop suicidal thoughts or actions, stop taking CHANTIX and call your doctor right away. Also tell your doctor about any history of depression or other mental health problems before taking CHANTIX, as these symptoms may worsen while taking CHANTIX.
The most common side effects include nausea (30%), sleep problems, constipation, gas, and/or vomiting. If you have side effects that bother you or don't go away, tell your doctor.
You may have trouble sleeping, vivid, unusual, or strange dreams while taking CHANTIX. You should use caution driving or operating machinery until you know how quitting smoking with CHANTIX may affect you.
CHANTIX should not be taken with other quit-smoking products. You may need a lower dose of CHANTIX if you have kidney problems or get dialysis.
Before starting CHANTIX, tell your doctor if you are pregnant, plan to become pregnant, or if you take insulin, asthma medicines, or blood thinners. Medicines like these may work differently when you quit smoking.
DESCRIPTION
CHANTIX� tablets contain the active ingredient, varenicline (as the tartrate salt), which is a
partial agonist selective for alpha4beta2 nicotinic acetylcholine receptor subtypes.
Varenicline, as the tartrate salt, is a powder which is a white to off-white to slightly yellow solid
with the following chemical name: 7,8,9,10-tetrahydro-6,10-methano-6H-pyrazino[2,3-
h][3]benzazepine, (2R,3R)-2,3-dihydroxybutanedioate (1:1). It is highly soluble in water.
Varenicline tartrate has a molecular weight of 361.35 Daltons, and a molecular formula of
C13H13N3 � C4H6O6. The chemical structure is:
CHANTIX is supplied for oral administration in two strengths: a 0.5 mg capsular biconvex,
white to off-white, film-coated tablet debossed with "Pfizer" on one side and "CHX 0.5" on the
other side and a 1 mg capsular biconvex, light blue film-coated tablet debossed with "Pfizer" on
one side and "CHX 1.0" on the other side.
Each 0.5 mg CHANTIX tablet contains 0.85 mg of
varenicline tartrate equivalent to 0.5 mg of varenicline free base; each 1mg CHANTIX tablet
contains 1.71 mg of varenicline tartrate equivalent to 1 mg of varenicline free base. The
following inactive ingredients are included in the tablets: microcrystalline cellulose, anhydrous
dibasic calcium phosphate, croscarmellose sodium, colloidal silicon dioxide, magnesium
stearate, Opadry� White (for 0.5 mg), Opadry� Blue (for 1 mg), and Opadry� Clear.
CLINICAL PHARMACOLOGY
Mechanism Of Action
Varenicline binds with high affinity and selectivity at alpha4beta2 neuronal nicotinic acetylcholine
receptors. The efficacy of CHANTIX in smoking cessation is believed to be the result of
varenicline�s activity at a sub-type of the nicotinic receptor where its binding produces agonist
activity, while simultaneously preventing nicotine binding to alpha4beta2 receptors.
Electrophysiology studies in vitro and neurochemical studies in vivo have shown that varenicline
binds to alpha4beta2 neuronal nicotinic acetylcholine receptors and stimulates receptor-mediated
activity, but at a significantly lower level than nicotine. Varenicline blocks the ability of nicotine
to activate alpha4beta2 receptors and thus to stimulate the central nervous mesolimbic dopamine system,
believed to be the neuronal mechanism underlying reinforcement and reward experienced upon
smoking. Varenicline is highly selective and binds more potently to alpha4beta2 receptors than to other
common nicotinic receptors (>500-fold �3�4, >3500-fold �7, >20,000-fold �1���), or to nonnicotinic
receptors and transporters (>2000-fold). Varenicline also binds with moderate affinity
(Ki = 350 nM) to the 5-HT3 receptor.
Pharmacokinetics
Absorption/Distribution
Maximum plasma concentrations of varenicline occur typically within 3-4 hours after oral
administration. Following administration of multiple oral doses of varenicline, steady-state
conditions were reached within 4 days. Over the recommended dosing range, varenicline exhibits
linear pharmacokinetics after single or repeated doses. In a mass balance study, absorption of
varenicline was virtually complete after oral administration and systemic availability was high.
Oral bioavailability of varenicline is unaffected by food or time-of-day dosing. Plasma protein
binding of varenicline is low (<=20%) and independent of both age and renal function.
Metabolism/Elimination
The elimination half-life of varenicline is approximately 24 hours. Varenicline undergoes
minimal metabolism with 92% excreted unchanged in the urine. Renal elimination of varenicline
is primarily through glomerular filtration along with active tubular secretion possibly via the
organic cation transporter, OCT2.
Pharmacokinetics In Special Patient Populations
There are no clinically meaningful differences in varenicline pharmacokinetics due to age, race,
gender, smoking status, or use of concomitant medications, as demonstrated in specific
pharmacokinetic studies and in population pharmacokinetic analyses.
Renal impairment
Varenicline pharmacokinetics were unchanged in subjects with mild renal impairment (estimated
creatinine clearance >50 mL/min and <80 mL/min). In patients with moderate renal impairment
(estimated creatinine clearance >30 mL/min and <50 mL/min), varenicline exposure increased
1.5-fold compared with subjects with normal renal function (estimated creatinine clearance >80
mL/min). In subjects with severe renal impairment (estimated creatinine clearance <30 mL/min),
varenicline exposure was increased 2.1-fold. In subjects with end-stage-renal disease (ESRD)
undergoing a three hour session of hemodialysis for three days a week, varenicline exposure was
increased 2.7-fold following 0.5 mg once daily administration for 12 days. The plasma Cmax and
AUC of varenicline noted in this setting were similar to healthy subjects receiving about 1 mg
twice daily. Caution is warranted with the use of CHANTIX in subjects with renal impairment
(See DOSAGE AND ADMINISTRATION). Additionally, in subjects with ESRD, varenicline
was efficiently removed by hemodialysis (See OVERDOSAGE).
Geriatric
A combined single and multiple-dose pharmacokinetic study demonstrated that the
pharmacokinetics of 1 mg varenicline given QD or BID to 16 healthy elderly male and female
smokers (aged 65-75 yrs) for 7 consecutive days was similar to that of younger subjects.
Pediatric
Because the safety and effectiveness of CHANTIX in pediatric patients have not been
established, CHANTIX is not recommended for use in patients under 18 years of age.
When 22 pediatric patients aged 12 to 17 years (inclusive) received a single 0.5 mg and 1 mgdose
of varenicline, the pharmacokinetics of varenicline was approximately dose proportional
between the 0.5 mg and 1 mg doses. Systemic exposure, as assessed by AUC(0-?), and renal
clearance of varenicline were comparable to those of an adult population.
Hepatic impairment
Due to the absence of significant hepatic metabolism, varenicline pharmacokinetics should be
unaffected in patients with hepatic insufficiency.
Drug-Drug Interactions
Drug interaction studies were performed with varenicline and digoxin, warfarin, transdermal
nicotine, bupropion, cimetidine and metformin. No clinically meaningful pharmacokinetic drugdrug
interactions have been identified.
In vitro studies demonstrated that varenicline does not inhibit the following cytochrome P450
enzymes (IC50 >6400 ng/mL): 1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, and 3A4/5. Also, in
human hepatocytes in vitro, varenicline does not induce the cytochrome P450 enzymes 1A2 and
3A4.
In vitro studies demonstrated that varenicline does not inhibit human renal transport proteins at
therapeutic concentrations. Therefore, drugs that are cleared by renal secretion (e.g. metformin -
see below) are unlikely to be affected by varenicline.
In vitro studies demonstrated the active renal secretion of varenicline is mediated by the human
organic cation transporter, OCT2. Co-administration with inhibitors of OCT2 may not require a
dose adjustment of CHANTIX as the increase in systemic exposure to CHANTIX is not
expected to be clinically meaningful (see Cimetidine interaction below). Furthermore, since
metabolism of varenicline represents less than 10% of its clearance, drugs known to affect the
cytochrome P450 system are unlikely to alter the pharmacokinetics of CHANTIX (see
Pharmacokinetics) and therefore a dose adjustment of CHANTIX would not be required.
Metformin: When co-administered to 30 smokers varenicline (1 mg BID) did not alter the
steady-state pharmacokinetics of metformin (500 mg BID), which is a substrate of OCT2.
Metformin had no effect on varenicline steady-state pharmacokinetics.
Cimetidine: Co-administration of an OCT2 inhibitor, cimetidine (300 mg QID), with varenicline
(2 mg single dose) to 12 smokers increased the systemic exposure of varenicline by 29% (90%
CI: 21.5%, 36.9%) due to a reduction in varenicline renal clearance.
Digoxin: Varenicline (1 mg BID) did not alter the steady-state pharmacokinetics of digoxin
administered as a 0.25 mg daily dose in 18 smokers.
Warfarin: Varenicline (1 mg BID) did not alter the pharmacokinetics of a single 25 mg dose of
(R, S)-warfarin in 24 smokers. Prothrombin time (INR) was not affected by varenicline.
Smoking cessation itself may result in changes to warfarin pharmacokinetics (see
PRECAUTIONS).
Use with other therapies for smoking cessation:
Bupropion: Varenicline (1 mg BID) did not alter the steady-state pharmacokinetics of bupropion
(150 mg BID) in 46 smokers. The safety of the combination of bupropion and varenicline has not
been established.
Nicotine replacement therapy (NRT): Although co-administration of varenicline (1 mg BID)
and transdermal nicotine (21 mg/day) for up to 12 days did not affect nicotine pharmacokinetics,
the incidence of nausea, headache, vomiting, dizziness, dyspepsia and fatigue was greater for the
combination than for NRT alone. In this study, eight of twenty-two (36%) subjects treated with
the combination of varenicline and NRT prematurely discontinued treatment due to adverse
events, compared to 1 of 17 (6%) of subjects treated with NRT and placebo.
Safety and efficacy of CHANTIX in combination with other smoking cessation therapies have
not been studied.
CLINICAL STUDIES
The efficacy of CHANTIX in smoking cessation was demonstrated in six clinical trials in which
a total of 3659 chronic cigarette smokers (>=10 cigarettes per day) were treated with CHANTIX.
In all clinical studies, abstinence from smoking was determined by patient self-report and
verified by measurement of exhaled carbon monoxide (CO?10 ppm) at weekly visits. Among the
CHANTIX treated patients enrolled in these studies, the completion rate was 65%. Except for the
initial Phase 2 study (Study 1) and the maintenance of abstinence study (Study 6), patients were
treated for 12 weeks and then were followed for 40 weeks post-treatment. Most subjects enrolled
in these trials were white (79% - 96%). All studies enrolled almost equal numbers of men and
women. The average age of subjects in these studies was 43 years. Subjects on average had
smoked about 21 cigarettes per day for an average of approximately 25 years.
In all studies, patients were provided with an educational booklet on smoking cessation and
received up to 10 minutes of smoking cessation counseling at each weekly treatment visit
according to Agency for Healthcare Research and Quality guidelines. Patients set a date to stop
smoking (target quit date, TQD) with dosing starting 1 week before this date.
Initiation of Abstinence
Study 1: This was a six-week dose-ranging study comparing CHANTIX to placebo. This study
provided initial evidence that CHANTIX at a total dose of 1 mg per day or 2 mg per day was
effective as an aid to smoking cessation.
Study 2: This study of 627 subjects compared CHANTIX 1 mg per day and 2 mg per day with
placebo. Patients were treated for 12 weeks (including one week titration) and then were
followed for 40 weeks post-treatment. CHANTIX was given in two divided doses. Each dose of
CHANTIX was given in two different regimens, with and without initial dose titration, to
explore the effect of different dosing regimens on tolerability. For the titrated groups, dosage was
titrated up over the course of one week, with full dosage achieved starting with the second week
of dosing. The titrated and nontitrated groups were pooled for efficacy analysis.
Forty five percent of subjects receiving CHANTIX 1 mg per day (0.5 mg BID) and 51% of
subjects receiving 2 mg per day (1 mg BID) had CO-confirmed continuous abstinence during
weeks 9 through 12 compared to 12% of subjects in the placebo group (Figure 1). In addition,
31% of the 1 mg per day group and 31% of the 2 mg per day group were continuously abstinent
from one week after TQD through the end of treatment as compared to 8% of the placebo group.
Study 3: This flexible-dosing study of 312 subjects examined the effect of a patient-directed
dosing strategy of CHANTIX or placebo. After an initial one-week titration to a dose of 0.5 mg
BID, subjects could adjust their dosage as often as they wished between 0.5 mg QD to 1 mg BID
per day. Sixty nine percent of patients titrated to the maximum allowable dose at any time during
the study. For 44% of patients, the modal dose selected was 1 mg BID; for slightly over half of
the study participants, the modal dose selected was 1 mg/day or less.
Of the subjects treated with CHANTIX, 40% had CO-confirmed continuous abstinence during
weeks 9 through 12 compared to 12% in the placebo group. In addition, 29% of the CHANTIX
group were continuously abstinent from one week after TQD through the end of treatment as
compared to 9% of the placebo group.
Study 4 and Study 5: These identical double-blind studies compared CHANTIX 2 mg per day,
bupropion sustained release (SR) 150 mg BID, and placebo. Patients were treated for 12 weeks
and then were followed for 40 weeks post-treatment. The CHANTIX dosage of 1 mg BID was
achieved using a titration of 0.5 mg QD for the initial 3 days followed by 0.5 mg BID for the
next 4 days. The bupropion SR dosage of 150 mg BID was achieved using a 3-day titration of
150 mg QD. Study 4 enrolled 1022 subjects and Study 5 enrolled 1023 subjects. Patients
inappropriate for bupropion treatment or patients who had previously used bupropion were
excluded.
In Study 4, subjects treated with CHANTIX had a superior rate of CO-confirmed abstinence
during weeks 9 through 12 (44%) compared to patients treated with bupropion SR (30%) or
placebo (17%). The bupropion SR quit rate was also superior to placebo. In addition, 29% of the
CHANTIX group were continuously abstinent from one week after TQD through the end of
treatment as compared to 12% of the placebo group and 23% of the bupropion SR group.
Similarly in Study 5, subjects treated with CHANTIX had a superior rate of CO-confirmed
abstinence during weeks 9 through 12 (44%) compared to patients treated with bupropion SR
(30%) or placebo (18%). The bupropion SR quit rate was also superior to placebo. In addition,
29% of the CHANTIX group were continuously abstinent from one week after TQD through the
end of treatment as compared to 11% of the placebo group and 21% of the bupropion SR group.
Figure 1: Continuous Abstinence, Weeks 9 through 12
Table 1: Continuous Abstinence, Weeks 9 through 12 (95% confidence interval) across different studies
Urge To Smoke
Based on responses to the Brief Questionnaire of Smoking Urges and the Minnesota Nicotine
Withdrawal scale �Urge to Smoke� item, CHANTIX reduced urge to smoke compared to
placebo in all studies.
Long-Term Abstinence
Studies 1 through 5 included 40 weeks of post-treatment follow-up. In each study, CHANTIX
treated patients were more likely to maintain abstinence throughout the follow-up period than
were patients treated with placebo (Figure 2, Table 2).
Figure 2: Continuous Abstinence, Weeks 9 through 52
Table 2: Continuous Abstinence, Weeks 9 through 52 (95% confidence interval) across different
studies
Study 6: This study assessed the effect of an additional 12 weeks of CHANTIX therapy on the
likelihood of long-term abstinence. Patients in this study (n=1927) were treated with open-label
CHANTIX 1 mg BID for 12 weeks. Patients who had stopped smoking by Week 12 were then
randomized to double-blind treatment with CHANTIX (1 mg BID) or placebo for an additional
12 weeks and then followed for 28 weeks post-treatment.
The continuous abstinence rate from Week 13 through Week 24 was higher for subjects
continuing treatment with CHANTIX (70%) than for subjects switching to placebo (50%).
Superiority to placebo was also maintained during 28 weeks post-treatment follow-up
(CHANTIX 54% versus placebo 39%).
In Figure 3 below, the x-axis represents the study week for each observation allowing a
comparison of groups at similar times after discontinuation of CHANTIX. Post-CHANTIX
follow-up begins at Week 13 for the placebo group and Week 25 for the CHANTIX group. The
y-axis represents the percent of subjects who had been abstinent for the last week of CHANTIX
treatment and remained abstinent at the given timepoint.
Figure 3: Continuous Abstinence Rate during nontreatment follow-up
INDICATIONS AND USAGE
CHANTIX is indicated as an aid to smoking cessation treatment.
WARNINGS
Neuropsychiatric Symptoms
Serious neuropsychiatric symptoms have occurred in patients being treated with CHANTIX.
Some cases may have been complicated by the symptoms of nicotine withdrawal in patients who
stopped smoking; however, some of these symptoms have occurred in patients who continued to
smoke. All patients being treated with CHANTIX should be observed for neuropsychiatric
symptoms including changes in behavior, agitation, depressed mood, suicidal ideation and
suicidal behavior. These symptoms, as well as worsening of pre-existing psychiatric illness,
have been reported in some patients attempting to quit smoking while taking CHANTIX in the
post-marketing experience. Patients with serious psychiatric illness such as schizophrenia,
bipolar disorder, and major depressive disorder did not participate in the pre-marketing studies of
CHANTIX and the safety and efficacy of CHANTIX in such patients has not been established.
Advise patients and caregivers that the patient should stop taking CHANTIX and contact a
health care provider immediately if agitation, depressed mood, or changes in behavior that
are not typical for the patient are observed, or if the patient develops suicidal ideation or
suicidal behavior
PRECAUTIONS
General:
Nausea was the most common adverse event associated with CHANTIX treatment. Nausea was
generally described as mild or moderate and often transient; however, for some subjects, it was
persistent over several months. The incidence of nausea was dose-dependent. Initial dosetitration
was beneficial in reducing the occurrence of nausea. Nausea was reported by
approximately 30% of patients treated with CHANTIX 1 mg BID after an initial week of dose
titration. In patients taking CHANTIX 0.5 mg BID, the incidence of nausea was 16% following
initial titration. Approximately 3% of subjects treated with CHANTIX 1 mg BID in studies
involving 12 weeks of treatment discontinued treatment prematurely because of nausea. For
patients with intolerable nausea, dose reduction should be considered.
Effect of smoking cessation: Physiological changes resulting from smoking cessation, with or
without treatment with CHANTIX, may alter the pharmacokinetics or pharmacodynamics of
some drugs, for which dosage adjustment may be necessary (examples include theophylline,
warfarin and insulin).
Drug Interactions
Based on varenicline characteristics and clinical experience to date, CHANTIX has no clinically
meaningful pharmacokinetic drug interactions (See CLINICAL PHARMACOLOGY, Drug-
Drug Interactions).
Carcinogenesis. Lifetime carcinogenicity studies were performed in CD-1 mice and Sprague-
Dawley rats. There was no evidence of a carcinogenic effect in mice administered varenicline by
oral gavage for 2 years at doses up to 20 mg/kg/day (47 times the maximum recommended
human daily exposure based on AUC). Rats were administered varenicline (1, 5, and 15
mg/kg/day) by oral gavage for 2 years. In male rats (n = 65 per sex per dose group), incidences
of hibernoma (tumor of the brown fat) were increased at the mid dose (1 tumor, 5 mg/kg/day, 23
times the maximum recommended human daily exposure based on AUC) and maximum dose (2
tumors, 15 mg/kg/day, 67 times the maximum recommended human daily exposure based on
AUC). The clinical relevance of this finding to humans has not been established. There was no
evidence of carcinogenicity in female rats.
Mutagenesis. Varenicline was not genotoxic, with or without metabolic activation, in the
following assays: Ames bacterial mutation assay; mammalian CHO/HGPRT assay; and tests for
cytogenetic aberrations in vivo in rat bone marrow and in vitro in human lymphocytes.
Impairment of fertility. There was no evidence of impairment of fertility in either male or female
Sprague-Dawley rats administered varenicline succinate up to 15 mg/kg/day (67 and 36 times,
respectively, the maximum recommended human daily exposure based on AUC at 1 mg BID).
However, a decrease in fertility was noted in the offspring of pregnant rats who were
administered varenicline succinate at an oral dose of 15 mg/kg/day (36 times the maximum
recommended human daily exposure based on AUC at 1 mg BID). This decrease in fertility in
the offspring of treated female rats was not evident at an oral dose of 3 mg/kg/day (9 times the
maximum recommended human daily exposure based on AUC at 1 mg BID).
Pregnancy
Pregnancy Category C.
Varenicline succinate was not teratogenic in rats and rabbits at oral doses up to 15 and 30
mg/kg/day, respectively (36 and 50-times the maximum recommended human daily exposure
based on AUC at 1 mg BID, respectively).
Nonteratogenic effects
Varenicline succinate has been shown to have an adverse effect on the fetus in animal
reproduction studies. Administration of varenicline succinate to pregnant rabbits resulted in
reduced fetal weights at an oral dose of 30 mg/kg/day (50 times the human AUC at 1 mg BID);
this reduction was not evident following treatment with 10 mg/kg/day (23 times the maximum
recommended daily human exposure based on AUC). In addition, in the offspring of pregnant
rats treated with varenicline succinate there were decreases in fertility and increases in auditory
startle response at an oral dose of 15 mg/kg/day (36 times the maximum recommended human
daily exposure based on AUC at 1 mg BID).
There are no adequate and well-controlled studies in pregnant women. CHANTIX should be
used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Nursing mothers
Although it is not known whether this drug is excreted in human milk, animal studies have
demonstrated that varenicline can be transferred to nursing pups. Because many drugs are
excreted in human milk and because of the potential for serious adverse reactions in nursing
infants from CHANTIX, 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.
Labor and delivery
The potential effects of CHANTIX on labor and delivery are not known.
Pediatric Use
Safety and effectiveness of CHANTIX in pediatric patients have not been established; therefore,
CHANTIX is not recommended for use in patients under 18 years of age.
Geriatric Use
A combined single and multiple-dose pharmacokinetic study demonstrated that the
pharmacokinetics of 1 mg varenicline given QD or BID to 16 healthy elderly male and female
smokers (aged 65-75 yrs) for 7 consecutive days was similar to that of younger subjects. 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.
Varenicline is known to be substantially excreted by the kidney, and the risk of toxic reactions 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 DOSAGE AND ADMINISTRATION, Special
Populations, Patients with impaired renal function).
No dosage adjustment is recommended for elderly patients (see DOSAGE AND
ADMINISTRATION, Special Populations).
Patients should be informed that quitting smoking, with or without CHANTIX, may be
associated with nicotine withdrawal symptoms (depression, agitation) or exacerbation of
pre-existing psychiatric illness. Some patients have experienced depressed mood,
agitation, changes in behavior, suicidal ideation and suicide when attempting to quit
smoking while taking CHANTIX. If patients develop agitation, depressed mood, or
changes in behavior that are not typical for them, or if patients develop suicidal ideation
or suicidal behavior, they should be urged to discontinue CHANTIX and report
symptoms to their health care providers.
Patients should be encouraged to reveal any history of psychiatric illness prior to
initiating treatment.
Patients should be informed that some medications may require dose adjustment after
quitting smoking.
Patients intending to become pregnant or planning to breast-feed an infant should be
advised of the risks of smoking and risks and benefits of smoking cessation with
CHANTIX.
Patients should be advised to use caution driving or operating machinery until they know
how quitting smoking with varenicline may affect them.
ADVERSE REACTIONS
During the premarketing development of CHANTIX, over 4500 individuals were exposed to
CHANTIX, with over 450 treated for at least 24 weeks and approximately 100 for a year. Most
study participants were treated for 12 weeks or less.
In Phase 2 and 3 placebo-controlled studies, the treatment discontinuation rate due to adverse
events in patients dosed with 1 mg BID was 12% for CHANTIX compared to 10% for placebo in
studies of three months� treatment. In this group, the discontinuation rates for the most common
adverse events in CHANTIX treated patients were as follows: nausea (3% vs. 0.5% for placebo),
headache (0.6% vs. 0.9% for placebo), insomnia (1.2% vs. 1.1% for placebo), and abnormal
dreams (0.3% vs. 0.2% for placebo).
Adverse Events were categorized using the Medical Dictionary for Regulatory Activities
(MedDRA, Version 7.1).
The most common adverse events associated with CHANTIX (>5% and twice the rate seen in
placebo-treated patients) were nausea, sleep disturbance, constipation, flatulence, and vomiting.
Smoking cessation, with or without treatment, is associated with nicotine withdrawal symptoms.
The most common adverse event associated with CHANTIX treatment is nausea. For patients
treated to the maximum recommended dose of 1 mg BID following initial dosage titration, the
incidence of nausea was 30% compared with 10% in patients taking a comparable placebo
regimen. In patients taking CHANTIX 0.5 mg BID following initial titration, the incidence was
16% compared with 11% for placebo. Nausea was generally described as mild or moderate and
often transient; however, for some subjects, it was persistent throughout the treatment period.
Table 3 shows the adverse events for CHANTIX and placebo in the 12 week fixed dose studies
with titration in the first week (Studies 2 (titrated arm only), 4, and 5). MedDRA High Level
Group Terms (HLGT) reported in < 5% of patients in the CHANTIX 1 mg BID dose group, and
more commonly than in the placebo group, are listed, along with subordinate Preferred Terms
(PT) reported in < 1% of CHANTIX patients (and at least 0.5% more frequent than placebo).
Closely related Preferred Terms such as �Insomnia�, �Initial insomnia�, �Middle insomnia�,
�Early morning awakening� were grouped, but individual patients reporting two or more grouped
events are only counted once.
Table 3: Common Treatment Emergent AEs (%) in the Fixed-Dose, Placebo-Controlled Studies (< 1%
in the 1 mg BID CHANTIX Group, and 1 mg BID CHANTIX at least 0.5% more than Placebo)
* Includes PTs Abdominal (pain, pain upper, pain lower, discomfort, tenderness, distension) and Stomach
discomfort
** Includes PTs Insomnia/Initial insomnia/Middle insomnia/Early morning awakening
The overall pattern, and the frequency of adverse events during the longer-term trials was very
similar to that described in Table 3, though several of the most common events were reported by
a greater proportion of patients. Nausea, for instance, was reported in 40% of patients treated
with CHANTIX 1 mg BID in a one-year study, compared to 8% of placebo-treated patients.
Following is a list of treatment-emergent adverse events reported by patients treated with
CHANTIX during all clinical trials. The listing does not include those events already listed in the
previous tables or elsewhere in labeling, those events for which a drug cause was remote, those
events which were so general as to be uninformative, and those events reported only once which
did not have a substantial probability of being acutely life-threatening.
BLOOD AND LYMPHATIC SYSTEM DISORDERS. Infrequent: Anemia,
Lymphadenopathy. Rare: Leukocytosis, Thrombocytopenia, Splenomegaly.
GENERAL DISORDERS AND ADMINISTRATION SITE CONDITIONS. Frequent:
Chest pain, Influenza like illness, Edema, Thirst. Infrequent: Chest discomfort, Chills, Pyrexia.
HEPATOBILIARY DISORDERS. Infrequent: Gall bladder disorder.
IMMUNE SYSTEM DISORDERS. Infrequent: Hypersensitivity. Rare: Drug
hypersensitivity.
INVESTIGATIONS. Frequent: Liver function test abnormal, Weight increased. Infrequent:
Electrocardiogram abnormal, Muscle enzyme increased, Urine analysis abnormal.
The following adverse events have been reported during post-approval use of Chantix. Because
these events are reported voluntarily from a population of uncertain size, it is not always possible
to reliably estimate their frequency or establish a causal relationship to drug exposure.
There have been reports of depressed mood, agitation, changes in behavior, suicidal ideation and
suicide in patients attempting to quit smoking while taking Chantix. Smoking cessation with or
without treatment is associated with nicotine withdrawal symptoms and the exacerbation of
underlying psychiatric illness. Not all patients had known pre-existing psychiatric illness and not
all had discontinued smoking. The role of Chantix in these reports is not known (see
WARNINGS).
DRUG ABUSE AND DEPENDENCE
Controlled Substance Class
Varenicline is not a controlled substance.
Humans: Fewer than 1 out of 1000 patients reported euphoria in clinical trials with CHANTIX.
At higher doses (greater than 2 mg), CHANTIX produced more frequent reports of
gastrointestinal disturbances such as nausea and vomiting. There is no evidence of doseescalation
to maintain therapeutic effects in clinical studies, which suggests that tolerance does
not develop. Abrupt discontinuation of CHANTIX was associated with an increase in irritability
and sleep disturbances in up to 3% of patients. This suggests that, in some patients, varenicline
may produce mild physical dependence which is not associated with addiction.
In a human laboratory abuse liability study, a single oral dose of 1 mg varenicline did not
produce any significant positive or negative subjective responses in smokers. In non-smokers, 1
mg varenicline produced an increase in some positive subjective effects, but this was
accompanied by an increase in negative adverse effects, especially nausea. A single oral dose of
3 mg varenicline uniformly produced unpleasant subjective responses in both smokers and nonsmokers.
Animals: Studies in rodents have shown that varenicline produces behavioral responses similar
to those produced by nicotine. In rats trained to discriminate nicotine from saline, varenicline
produced full generalization to the nicotine cue. In self-administration studies, the degree to
which varenicline substitutes for nicotine is dependent upon the requirement of the task. Rats
trained to self-administer nicotine under easy conditions continued to self-administer varenicline
to a degree comparable to that of nicotine, however in a more demanding task, rats selfadministered
varenicline to a lesser extent than nicotine. Varenicline pretreatment also reduced
nicotine self-administration.
OVERDOSAGE
Overdosage of cephalosporins can cause cerebral irritation leading to convulsions. Serum levels of cefuroxime can be reduced by hemodialysis and peritoneal dialysis.
In case of overdose, standard supportive measures should be instituted as required.
Varenicline has been shown to be dialyzed in patients with end stage renal disease (see
CLINICAL PHARMACOLOGY, Pharmacokinetics, Pharmacokinetics in Special Patient
Populations), however, there is no experience in dialysis following overdose.
DOSAGE AND ADMINISTRATION
Usual Dosage for Adults
Smoking cessation therapies are more likely to succeed for patients who are motivated to stop
smoking and who are provided additional advice and support. Patients should be provided with
appropriate educational materials and counseling to support the quit attempt.
The patient should set a date to stop smoking. CHANTIX dosing should start one week before
this date.
CHANTIX should be taken after eating and with a full glass of water.
The recommended dose of CHANTIX is 1 mg twice daily following a 1-week titration as
follows:
Days 1 � 3: ..... 0.5 mg once daily
Days 4 � 7: ..... 0.5 mg twice daily
Day 8 � End of treatment: ..... 1 mg twice daily
Patients who cannot tolerate adverse effects of CHANTIX may have the dose lowered
temporarily or permanently.
Patients should be treated with CHANTIX for 12 weeks. For patients who have successfully
stopped smoking at the end of 12 weeks, an additional course of 12 weeks treatment with
CHANTIX is recommended to further increase the likelihood of long-term abstinence.
Patients who do not succeed in stopping smoking during 12 weeks of initial therapy, or who
relapse after treatment, should be encouraged to make another attempt once factors contributing
to the failed attempt have been identified and addressed.
Special Populations
Patients with impaired renal function
No dosage adjustment is necessary for patients with mild to moderate renal impairment.
For patients with severe renal impairment, the recommended starting dose of CHANTIX is 0.5
mg once daily. Patients may then titrate as needed to a maximum dose of 0.5 mg twice a day. For
patients with end-stage renal disease undergoing hemodialysis, a maximum dose of 0.5 mg once
daily may be administered if tolerated well (See CLINICAL PHARMACOLOGY,
Pharmacokinetics, Pharmacokinetics in Special Populations, Renal impairment).
Dosing in elderly patients and patients with impaired hepatic function
No dosage adjustment is necessary for patients with hepatic impairment. 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, Geriatric Use).
Use in children
Safety and effectiveness of CHANTIX in pediatric patients have not been established; therefore,
CHANTIX is not recommended for use in patients under 18 years of age.
HOW SUPPLIED
CHANTIX is supplied for oral administration in two strengths: a 0.5 mg capsular biconvex,
white to off-white, film-coated tablet debossed with "Pfizer" on one side and "CHX 0.5" on the
other side and a 1 mg capsular biconvex, light blue film-coated tablet debossed with "Pfizer" on
one side and "CHX 1.0" on the other side. CHANTIX is supplied in the following package
configurations:
STORAGE AND HANDLING
Store at 25oC (77oF); excursions permitted to 15�30oC (59�86oF) (see USP Controlled Room
Temperature).
- To bookmark this page (add it to your favorites), please click the image to the left.
- If you wish to link to this page, you can do so by referring to the URL address below this line.
https://theodora.com/drugs/chantix_varenicline_tablets_pfizer.html