Dosing & Uses
Dosage Forms & Strengths
tablet
- 0.5mg
- 1mg
Smoking Cessation
Set a date to stop smoking and begin varenicline 1 week before this date
Alternatively, the patient can begin varenicline and then quit smoking between days 8 and 35 of treatment
Also see Administration
Quit smoking date regimen
- Initiate regimen 1 week before quit smoking date
- Days 1-3: 0.5 mg PO qDay
- Days 4-7: 0.5 mg PO BID
- Day 8 to end of treatment: 1 mg PO BID
- If quitting is successful after 12 weeks, continue another 12 weeks at 1 mg q12hr
Gradual approach to quitting
- For patients who are sure that they are not able or willing to quit abruptly, consider a gradual approach to quitting smoking with varenicline
- Begin dosing and reduce smoking by 50% from baseline within the first 4 weeks, by an additional 50% in the next 4 weeks, and continue reducing with the goal of reaching complete abstinence by 12 weeks
- Continue varenicline for an additional 12 weeks, for a total of 24 weeks of treatment
- Encourage patients to attempt quitting sooner if they feel ready
Dosage Modifications
Consider a temporary or permanent dose reduction in patients who cannot tolerate the adverse effects
Renal impairment
- Mild-to-moderate (CrCl ≥30 mL/min): No dosage adjustment required
- Severe (CrCl <30 mL/min): 0.5 mg PO qDay initially; may increase to 0.5 mg PO q12hr
- ESRD on hemodialysis: Not to exceed 0.5 mg PO qDay
<18 years: Safety and efficacy not established
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (0)
Serious - Use Alternative (2)
- tafenoquine
tafenoquine will increase the level or effect of varenicline by Other (see comment). Avoid or Use Alternate Drug. Tafenoquine inhibits organic cation transporter-2 (OCT2) and multidrug and toxin extrusion (MATE) transporters in vitro. Avoid coadministration with OCT2 or MATE substrates. If coadministration cannot be avoided, monitor for substrate-related toxicities and consider dosage reduction if needed based on product labeling of the coadministered drug.
- trilaciclib
trilaciclib will decrease the level or effect of varenicline by Other (see comment). Avoid or Use Alternate Drug. Avoid coadministration of trilaciclib (OCT2, MATE1, and MATE-2K inhibitor) with substrates where minimal increased concentration in kidney or blood may lead to serious or life-threatening toxicities.
Monitor Closely (10)
- dichlorphenamide
dichlorphenamide and varenicline both decrease serum potassium. Use Caution/Monitor.
- erdafitinib
erdafitinib increases levels of varenicline by increasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.
- ethanol
varenicline increases effects of ethanol by unspecified interaction mechanism. Modify Therapy/Monitor Closely. Coadministration have resulted in some patients experiencing increased intoxicating effects of alcohol, sometimes associated with aggressive behavior and/or amnesia. Advise patients to reduce the amount of alcohol they consume while taking varenicline until they know whether it affects their tolerance for alcohol.
- famotidine
famotidine will increase the level or effect of varenicline by decreasing renal clearance. Use Caution/Monitor.
- ibuprofen/famotidine
ibuprofen/famotidine will increase the level or effect of varenicline by decreasing renal clearance. Use Caution/Monitor.
- nicotine inhaled
varenicline increases toxicity of nicotine inhaled by Other (see comment). Use Caution/Monitor. Comment: Varenicline is a partial agonist at the nicotinic Ach receptor; concomitant use with nicotine replacement therapy may increase adverse effects.
- nicotine intranasal
varenicline increases toxicity of nicotine intranasal by Other (see comment). Use Caution/Monitor. Comment: Varenicline is a partial agonist at the nicotinic Ach receptor; concomitant use with nicotine replacement therapy may increase adverse effects.
- nizatidine
nizatidine will increase the level or effect of varenicline by decreasing renal clearance. Use Caution/Monitor.
- tobramycin inhaled
tobramycin inhaled and varenicline both increase nephrotoxicity and/or ototoxicity. Modify Therapy/Monitor Closely. Avoid concurrent or sequential use to decrease risk for ototoxicity
- vandetanib
vandetanib increases levels of varenicline by Other (see comment). Modify Therapy/Monitor Closely. Comment: Vandetanib inhibits the uptake of substrates of organic cation transporter type 2 (OCT2).
Minor (2)
- cimetidine
cimetidine increases levels of varenicline by decreasing renal clearance. Minor/Significance Unknown.
- isavuconazonium sulfate
isavuconazonium sulfate will increase the level or effect of varenicline by Other (see comment). Minor/Significance Unknown. Isavuconazonium sulfate, an OCT2 inhibitor, may increase the effects or levels of OCT2 substrates.
Adverse Effects
>10%
Nausea (15-40%; dose related)
Abnormal dreams
Headache
Insomnia
1-10%
Appetite changes
Chest pain
Constipation
Dry mouth
Dyspepsia
Dyspnea
Flatulence
Gastroesophageal reflux disease (GERD)
Fatigue or lethargy
Pruritus
Rash
Somnolence
Rhinorrhea
Vomiting
Upper respiratory tract disorder
Frequency Not Defined (selected)
Abnormal liver function tests
Anemia
Anxiety
Arrhythmia
Arthralgia
Depression
Diarrhea
Dizziness
Epistaxis
Hypertension
Myocardial infarction (MI)
Polyuria
Respiratory disorder
Postmarketing Reports
Depression, mania, psychosis, hallucinations, paranoia, delusions, homicidal ideation, aggression, hostility, anxiety, and panic, as well as suicidal ideation, suicide attempt, and completed suicide, somnambulism
Serious skin reactions, including Stevens-Johnson syndrome
Cerebrovascular accident
Seizures
MI
Cardiovascular: During nontreatment follow-up to 52 weeks, adjudicated events comparing patients with stable cardiovascular disease to premarket studies included need for coronary revascularization (2.0% vs 0.6%), hospitalization for angina pectoris (1.7% vs 1.1%), and new diagnosis of peripheral vascular disease (PVD) or admission for PVD procedure (1.4% vs 0.6%)
Irritability
Agitation
Somnambulism
Warnings
Contraindications
Documented hypersensitivity or skin reactions to drug or components of formulation
Nonsmokers
Cautions
May cause nausea; reduce dose if nausea occurs
Somnambulism reported, including cases describing harmful behavior to self, others, or property; instruct patients to discontinue varenicline and notify their healthcare professional
Seizures reported; some patients had no history of seizures, whereas others had a history of seizure disorder that was remote or well-controlled; in most cases, the seizure occurred within the first month of therapy; use with caution in patients with history of seizures or with other factors that might lower seizure threshold
May cause CNS depression; use caution when performing tasks requiring mental alertness, such as, operating heavy machinery or driving
Hypersensitivity reactions reported, including angioedema
Rare but serious skin reactions reported, including Stevens-Johnson Syndrome and erythema multiforme
Neuropsychiatric adverse effects
- Serious neuropsychiatric adverse events reported; these postmarketing reports include changes in mood (including depression and mania), psychosis, hallucinations, paranoia, delusions, homicidal ideation, aggression, hostility, agitation, anxiety, and panic, as well as suicidal ideation, suicide attempt, and completed suicide
- Some patients who stopped smoking may have been experiencing symptoms of nicotine withdrawal, including depressed mood
- Depression, rarely including suicidal ideation, has been reported in smokers undergoing a smoking cessation attempt without medication; however, some of these adverse events occurred in patients taking varenicline who continued to smoke
- Neuropsychiatric adverse events occurred in patients without and with pre-existing psychiatric disease; some patients experienced worsening of their psychiatric illnesses
- Some neuropsychiatric adverse events, including unusual and sometimes aggressive behavior directed to oneself or others, may have been worsened by concomitant use of alcohol
- Advise patients and caregivers that the patient should stop taking varenicline and contact a healthcare provider immediately if agitation, depressed mood, or changes in behavior or thinking that are not typical are observed, or if the patient develops suicidal ideation or suicidal behavior
Alcohol interaction
- Patients should reduce amount alcohol they consume when initiating therapy until they know whether it increases intoxicating effects
- Postmarketing reports of patients experiencing increased intoxicating effects of alcohol while taking varenicline; some cases described unusual and sometimes aggressive behavior, and were often accompanied by amnesia for the events
Cardiovascular risk
- May increase risk of cardiovascular events in patients with underlying cardiovascular disease; randomized, double-blind, placebo-controlled study of 700 patients treated with varenicline for smoking cessation found increases in risk of nonfatal MI, need for revascularization, angina pectoris, and peripheral vascular disease
- In FDA meta-analysis, varenicline (compared with placebo) showed nonsignificant increase in risk for major adverse cardiovascular events (ie, combined outcome of cardiovascular-related death, nonfatal heart attack, and nonfatal stroke); these events were uncommon in both groups
Pregnancy & Lactation
Pregnancy
Available data have not suggested increased risk for major birth defects following exposure to varenicline in pregnancy, compared with women who smoke; smoking during pregnancy causes increased risks of orofacial clefts, premature rupture of membranes, placenta previa, placental abruption, ectopic pregnancy, fetal growth restriction and low birth weight, stillbirth, preterm delivery and shortened gestation, neonatal death, sudden infant death syndrome and reduction of lung function in infants; it is not known whether quitting smoking with varenicline during pregnancy reduces these risks
Lactation
Because there are no data on presence of varenicline in human milk and effects on breastfed infant, breastfeeding women should monitor their infant for seizures and excessive vomiting, which are adverse reactions that have occurred in adults that may be clinically relevant in breastfeeding infants
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Agonist at nicotinic receptors; acts on mesolimbic dopamine system associated with nicotine addiction, where it prevents nicotine stimulation; stimulates nicotine activity but to lesser degree than nicotine does
Absorption
Completely absorbed
Bioavailability: High
Peak plasma time: 3-4 hr
Distribution
Protein bound: <20%
Metabolism
Minimally metabolized
Elimination
Excretion: Urine (92%)
Half-life: 24 hr
Excretion: Urine (92%)
Administration
Oral Administration
Take dose after eating with full glass of water
Set date to stop smoking, and start varenicline 1 week before that date; alternatively, the patient can begin varenicline dosing and then quit smoking between days 8 and 35 of treatment
Patients who are motivated to quit, and who did not succeed in stopping smoking during prior varenicline therapy for reasons other than intolerability due to adverse events or who relapsed after treatment, should be encouraged to make another attempt with varenicline once factors contributing to the failed attempt have been identified and addressed
Images
BRAND | FORM. | UNIT PRICE | PILL IMAGE |
---|---|---|---|
Chantix Starting Month Box oral - | 0.5 mg (11)- 1 mg (42) tablet | ![]() | |
Chantix Continuing Month Box oral - | 1 mg tablet | ![]() | |
Chantix oral - | 1 mg tablet | ![]() | |
Chantix oral - | 0.5 mg tablet | ![]() | |
varenicline oral - | 1 mg tablet | ![]() | |
varenicline oral - | 1 mg tablet | ![]() | |
varenicline oral - | 0.5 mg tablet | ![]() | |
varenicline oral - | 1 mg tablet | ![]() | |
varenicline oral - | 1 mg tablet | ![]() | |
varenicline oral - | 0.5 mg tablet | ![]() | |
varenicline oral - | 0.5 mg (11)- 1 mg (42) tablet | ![]() | |
varenicline oral - | 0.5 mg tablet | ![]() |
Copyright © 2010 First DataBank, Inc.
Patient Handout
varenicline oral
VARENICLINE - ORAL
(var-EN-i-kleen)
COMMON BRAND NAME(S): Chantix
USES: Varenicline is used by adults to help stop smoking. To increase your chance of success, use this medication with a stop-smoking program that includes education, support, and counseling. Quitting smoking lowers your risk of heart and lung disease, as well as cancer. Varenicline works by blocking nicotine's effects in the brain that make you want to smoke.Discuss the risks and benefits of this medication, as well as other ways to quit smoking (such as nicotine replacement treatment), with your doctor.
HOW TO USE: Read the Medication Guide provided by your pharmacist before you start taking varenicline and each time you get a refill. If you have any questions, ask your doctor or pharmacist.There are different ways to use varenicline. One way is to set a date to quit smoking before beginning treatment with this drug. Begin taking varenicline as directed by your doctor, 1 to 2 weeks before the quit date. Take one 0.5-milligram tablet once a day for 3 days, then increase to one 0.5-milligram tablet twice a day for 4 days. The dose is slowly increased to lessen the chance of side effects (such as nausea, unusual dreams). It is okay to smoke during this time. Stop smoking on the quit date. Take the dose prescribed by your doctor twice a day for the rest of the treatment period (usually 12 weeks).Another way to use varenicline is to start taking the drug before you choose a date to quit smoking. Start with the 0.5-milligram tablets and increase the dose as directed by your doctor. Pick a date to quit smoking that is between days 8 and 35 of treatment. Stop smoking on the date you have chosen. Take the dose prescribed by your doctor for the rest of the treatment period.If you are not able to pick a quit date, your doctor may direct you to start taking this medication and gradually reduce smoking with a goal to quit by the end of your treatment. Follow your doctor's directions carefully and reduce smoking as directed.If this medication comes in a dosing package, carefully follow the directions on the dosing package. There are two types of dosing packs: a starting pack and a continuing pack, each containing different strengths of this medication. If this medication comes in a bottle, carefully follow your doctor's directions on the prescription label. If you have any questions about how to take this medication, talk to your doctor or pharmacist.Take this medication by mouth after eating food and with a full glass of water.The dosage is based on your medical condition and response to treatment.Do not increase your dose or take this medication more often than prescribed. Your condition will not improve any faster, and your risk of side effects will increase. Do not take more than 1 milligram twice a day.Take this medication regularly to get the most benefit from it. To help you remember, take it at the same time(s) each day.Tell your doctor if you continue to smoke after a few weeks of treatment. If you are not able to quit smoking after 12 weeks of treatment, talk to your doctor.If you are successful and cigarette-free after 12 weeks of treatment, your doctor may recommend another 12 weeks of treatment with varenicline.
SIDE EFFECTS: See also Precautions section.Nausea, headache, vomiting, drowsiness, gas, constipation, trouble sleeping, unusual dreams, or changes in taste may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: burning feeling in feet/toes, unusual pain in the legs when walking.Stop taking varenicline and get medical help right away if you have any very serious side effects, including: seizure, symptoms of a heart attack (such as chest/jaw/left arm pain, shortness of breath, unusual sweating), signs of a stroke (such as weakness on one side of the body, trouble speaking, sudden vision changes, confusion), harmful behavior to self/others/property.Rarely, varenicline may cause serious mental/mood changes, even after stopping the medication. Drinking alcohol while taking this medication may increase the risk for mental/mood changes. Quitting smoking itself may also cause mental/mood changes. Stop taking varenicline and tell your doctor or pharmacist right away if you have symptoms such as depression/suicidal thoughts, agitation, aggression, or other unusual thoughts or behavior.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking varenicline, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney disease, mental/mood disorders (such as schizophrenia, bipolar disorder, depression), heart/blood vessel disease (such as coronary artery disease, peripheral vascular disease, stroke), seizure.This drug may make you dizzy, drowsy, lose consciousness, or make it difficult to concentrate. Alcohol or marijuana (cannabis) can worsen these effects. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Talk to your doctor if you are using marijuana (cannabis).This drug may also make you more sensitive to alcohol (including increased drunkenness, unusual behavior, and limited or no memory of things that happened). Limit alcoholic beverages. Be aware of how alcohol affects you while taking this medication.During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.It is unknown if this medication passes into breast milk. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Smoking can affect the way your body removes certain drugs such as insulin, theophylline, warfarin, among others. When you stop smoking, your doses of these drugs may need to be adjusted by your doctor. Tell all your doctors and pharmacists that you are quitting smoking and of all the products you take.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
NOTES: Do not share this medication with others.
MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised August 2021. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
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