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 dose-titration 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.
Accidental Injury
There have been post-marketing reports of traffic accidents, near-miss incidents in traffic,
or other accidental injuries in patients taking CHANTIX. In some cases, the patients reported
somnolence, dizziness, loss of consciousness or difficulty concentrating that resulted in
impairment, or concern about potential impairment, in driving or operating machinery.
Patients should be advised to use caution driving or operating machinery or engaging in
other potentially hazardous activities until they know how CHANTIX may affect them.
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, Mutagenesis, Impairment of Fertility
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 ).
Information for Patients:
Patients should be instructed to set a date to quit smoking and
to initiate CHANTIX treatment one week before the quit date.
Patients should be advised that CHANTIX should be taken after eating,
and with a full glass of water.
Patients should be instructed how to titrate CHANTIX, beginning
at a dose of 0.5 mg/day. Prescribers should explain that one 0.5 mg
tablet should be taken daily for the first three days, and that for
the next four days, one 0.5 mg tablet should be taken in the morning
and one 0.5 mg tablet should be taken in the evening.
Patients should be advised that, after the first seven days, the
dose should be increased to one 1 mg tablet in the morning and one 1
mg tablet in the evening.
Patients should be encouraged to continue to attempt to quit if
they have early lapses after quit day.
Patients should also be provided with educational materials and
necessary counseling to support an attempt at quitting smoking.
Patients should be informed that nausea and insomnia are side effects
of CHANTIX and are usually transient; however, patients should be advised
that if they are persistently troubled by these symptoms, they should
notify the prescribing physician so that a dose reduction can be considered.
Patients should be informed that they may experience vivid, unusual
or strange dreams during treatment with CHANTIX.
Patients should be informed that quitting smoking, with or without CHANTIX,
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 and suicide when attempting to quit smoking while taking CHANTIX.
If patients develop agitation, hostility, depressed mood, or changes in behavior or
thinking that are not typical for them, or if patients develop suicidal ideation or
behavior, they should be urged to discontinue CHANTIX and report these symptoms to
their healthcare provider immediately.
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.
Patients should be informed that there have been reports of angioedema, with swelling
of the face, mouth (lip, gum, tongue) and neck (larynx and pharynx) that can lead
to life-threatening respiratory compromise. Patients should be instructed to discontinue
CHANTIX and immediately seek medical care if they experience these symptoms.
Patients should be informed that serious skin reactions, such as Stevens Johnson Syndrome
and Erythema Multiforme, were reported by some patients taking CHANTIX. They should be
advised to stop taking CHANTIX at the first sign of rash with mucosal lesions or skin
reaction and contact a health care provider immediately.