Prescription medication · Nicotinic Receptor Partial Agonist
varenicline
Also sold as Chantix. Varenicline is used to help adults stop smoking.
Data updated 2026-05-15
- 5,766
- FDA reportsLightly reported
- 3
- InteractionsFew interactions
- 2
- Recall records
What the data shows
varenicline (Chantix) is a prescription Nicotinic Receptor Partial Agonist, reported less often than most tracked drugs (5,766 FDA reports), with 3 documented drug interactions.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
varenicline (Chantix) is a prescription Nicotinic Receptor Partial Agonist. Varenicline is used to help adults stop smoking.
Varenicline (Chantix) is a medicine that can help you stop smoking. It works on receptors in the brain to reduce cravings and withdrawal symptoms.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Generic Price
$0.67/unit
Generic Available
Yes (18 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
Varenicline is used to help adults stop smoking.
Common side effects
Feeling sick to your stomach, Strange or vivid dreams, Constipation
Key warnings
Varenicline can cause changes in your mood or behavior.
The sections below are summarized in plain English from varenicline's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Varenicline works by attaching to certain receptors in your brain. These receptors are called nicotinic receptors. By attaching to them, varenicline reduces cravings and withdrawal symptoms linked to nicotine addiction.
Side Effects (from patient reports)
Based on 5,766 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for varenicline, by number of reports
- Sneezing
Sneezing
732 reports
- Nausea
Nausea
558 reports
- Vomiting
Vomiting
381 reports
- Depression
Depression
349 reports
- Headache 289
Headache
289 reports
- Nasal Discomfort 260
Nasal Discomfort
260 reports
- Product Delivery Mechanism Issue 252
Product Delivery Mechanism Issue
252 reports
- Rhinorrhoea 226
Rhinorrhoea
226 reports
- Nightmare 212
Nightmare
212 reports
- Abnormal Dreams 210
Abnormal Dreams
210 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for varenicline each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where varenicline sits
varenicline has more FDA adverse-event reports than 27% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is varenicline; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 5,766 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2007–2025.
Total Reports
5,766
Reports Mentioning Death
65
1.1% of reports — not proof of cause
Hospitalization Reports
469
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | SNEEZING | 732 |
| 2 | NAUSEA | 558 |
| 4 | VOMITING | 381 |
| 5 | DEPRESSION | 349 |
| 6 | HEADACHE | 289 |
| 7 | NASAL DISCOMFORT | 260 |
| 8 | PRODUCT DELIVERY MECHANISM ISSUE | 252 |
| 9 | RHINORRHOEA | 226 |
| 10 | NIGHTMARE | 212 |
| 11 | ABNORMAL DREAMS | 210 |
| 12 | SUICIDAL IDEATION | 207 |
| 13 | COUGH | 196 |
| 14 | INSOMNIA | 188 |
| 15 | EYE PAIN | 181 |
| 16 | THROAT IRRITATION | 178 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Varenicline can cause changes in your mood or behavior. These can include depression, anxiety, aggression, and suicidal thoughts. If you have these symptoms, stop taking varenicline and call your doctor right away. Varenicline may also increase your risk of seizures, accidental injuries, heart problems, sleepwalking, and severe allergic reactions.
Known Drug Interactions
Bupropion Varenicline (1 mg twice daily) did not alter the steady-state pharmacokinetics of bupropion (150 mg twice daily) in 46 smokers. The safety of the combination of bupropion and varenicline has not been established.
Mechanism: These drugs do not change each other's levels in the body, but it is not yet known if taking them together is safe.
( 7.1 ) Effect of Smoking Cessation on Other Drugs: Pharmacokinetics or pharmacodynamics of certain drugs (e.g., theophylline, warfarin, insulin) may be altered, necessitating dose adjustment. 7.2 Effect of Smoking Cessation on Other Drugs Physiological changes resulting from smoking cessation, with or without treatment with varenicline, may alter the pharmacokinetics or pharmacodynamics of certain drugs (e.g., theophylline, warfarin, insulin) for which dosage adjustment may be necessary.
Mechanism: Quitting smoking causes changes in the body that can change how well this medicine works.
( 7.1 ) Effect of Smoking Cessation on Other Drugs: Pharmacokinetics or pharmacodynamics of certain drugs (e.g., theophylline, warfarin, insulin) may be altered, necessitating dose adjustment. 7.2 Effect of Smoking Cessation on Other Drugs Physiological changes resulting from smoking cessation, with or without treatment with varenicline, may alter the pharmacokinetics or pharmacodynamics of certain drugs (e.g., theophylline, warfarin, insulin) for which dosage adjustment may be necessary.
Mechanism: The physical changes that happen when you stop smoking can change how your body handles this medication.
This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.
Common Questions
How long do I need to take varenicline?
Can I use nicotine patches while taking varenicline?
What if I can't quit smoking suddenly?
What should I do if I feel depressed while taking varenicline?
Can I drink alcohol while taking varenicline?
What if I have kidney problems?
Can varenicline cause sleepwalking?
What are the signs of a serious allergic reaction?
What if I still feel the urge to smoke?
Is it okay to take other medications with varenicline?
What are the common side effects of varenicline?
Does varenicline interact with other medications?
What drug class is varenicline?
What pregnancy or breastfeeding source fields are listed for varenicline?
Has varenicline been recalled?
Active Recalls
Sub potent drug: during the 9-month stability test conducted, the assay value for the affected lot was below specification limit.
Dr. Reddy's Laboratories, Inc.
CGMP Deviations: Presence of the N-nitroso-varenicline impurity above FDA s acceptable interim acceptable intake limit
Pfizer Inc.
Related Medications in Nicotinic Receptor Partial Agonist
Other drugs grouped near varenicline - same-class peers and common alternatives.
acamprosate
Campral
Acamprosate is a medicine that can help you stay away from alcohol if you are alcohol-dependent and have already stopped drinking.
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alprazolam
Xanax
Alprazolam (Xanax) is a medication that can help you with anxiety and panic disorders.
Compare with varenicline →
amitriptyline
Elavil
Amitriptyline is a medicine used to treat depression.
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amphetamine/dextroamphetamine
Adderall, Adderall XR
Adderall XR is a stimulant medicine.
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aripiprazole
Abilify
Aripiprazole (Abilify) is a medicine used to treat certain mental disorders and mood problems.
Compare with varenicline →
Compare beyond drug class
Nationwide peers by FAERS volume & death-report share
Two PlainMeds-derived comparison paths for varenicline: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.
Similar FAERS report volume
Nearest drugs by total FAERS reports. This record: 5,766.
Similar death-report share
Nearest drugs by FAERS death-report share. This record: 1.13%.
Medication Guides
Understanding Drug Interactions
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Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
FDA bioequivalence and label-record context for narrow therapeutic index medicines
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
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What the FDA Data Shows for varenicline
The FDA label for varenicline (sold under brand names such as Chantix) classifies it as a prescription-only medication in the Nicotinic Receptor Partial Agonist class. Varenicline is used to help adults stop smoking. Official labeling lists 5 commonly reported side effects, including Feeling sick to your stomach, Strange or vivid dreams, Constipation.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 5,766 voluntary reports. The database also lists 3 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated minor severity. NADAC pricing from CMS shows a generic unit cost of $0.67.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 2 recall records on file), and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.
Last updated: May 8, 2025
PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages