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Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Brand Name
Varenicline
Generic Name
Varenicline
Active Ingredient
VareniclineCategory
Other
Salt Form
Tartrate
Variants
28
Different strengths and dosage forms
| Strength | Form | Route | NDC |
|---|---|---|---|
| .5 mg/1 | TABLET, FILM COATED | ORAL | 0378-5089 |
| .5 mg/1 | TABLET, FILM COATED | ORAL | 70748-127 |
| .5 mg/1 | TABLET, FILM COATED | ORAL | 70710-1613 |
References used for this content
This page is for informational purposes only and does not replace medical advice. Before using any prescription or over-the-counter medication for Varenicline, you must consult a qualified healthcare professional.
| .5 mg/1 | TABLET, FILM COATED | ORAL | 70771-1773 |
| 1 mg/1 | TABLET, FILM COATED | ORAL | 33342-490 |
| .5 mg/1 | TABLET, FILM COATED | ORAL | 33342-489 |
| .5 mg/1 | TABLET, FILM COATED | ORAL | 50090-6447 |
| KIT | ORAL | 60505-3615 |
| KIT | — | 0378-5091 |
| 1 mg/1 | TABLET, FILM COATED | ORAL | 72162-2219 |
| .5 mg/1 | TABLET | ORAL | 60290-077 |
| 1 mg/1 | TABLET, FILM COATED | ORAL | 60505-4795 |
+ 16 more variants
Detailed information about Varenicline
Varenicline is a prescription partial nicotinic agonist used as a highly effective aid for smoking cessation. It works by reducing nicotine cravings and decreasing the pleasurable effects of tobacco products.
The standard dosing regimen for varenicline follows a specific upward titration (gradual increase) to allow the body to adjust to the medication and minimize side effects, particularly nausea.
Patients should typically start taking varenicline one week before their 'Quit Date' (the day they plan to stop smoking entirely). This allows the drug to reach steady-state levels in the brain. The standard duration of treatment is 12 weeks. If a patient successfully quits by the end of 12 weeks, a healthcare provider may recommend an additional 12 weeks of treatment (totaling 24 weeks) to further increase the chances of long-term abstinence and prevent relapse.
Varenicline is not approved for use in pediatric patients (children and adolescents under the age of 18). Clinical trials involving adolescents (ages 12 to 17) failed to demonstrate a significant benefit over placebo for smoking cessation, and the safety profile in this age group has not been fully established for long-term use.
Because varenicline is primarily eliminated by the kidneys, dosage adjustments are necessary for patients with significant kidney dysfunction.
Since varenicline undergoes minimal hepatic metabolism, no dosage adjustment is necessary for patients with liver disease (hepatic impairment).
No specific dose adjustments are required for elderly patients solely based on age. However, because older adults are more likely to have decreased renal function, healthcare providers should assess kidney health before determining the appropriate dose.
If you miss a dose of varenicline, take it as soon as you remember. However, if it is almost time for your next scheduled dose, skip the missed dose and return to your regular schedule. Do not take two doses at once to make up for a missed one, as this increases the risk of side effects.
Symptoms of a varenicline overdose may include severe nausea, vomiting, dizziness, or intensified side effects. In the event of a suspected overdose, contact your local poison control center or seek emergency medical attention immediately. Treatment is generally supportive, as varenicline can be removed by hemodialysis in severe cases, but there is no specific antidote.
> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose or stop the medication prematurely without medical guidance, as this may increase your risk of returning to smoking.
The most frequently reported side effect of varenicline is nausea, affecting approximately 30% of patients. This is usually mild to moderate and often diminishes over time. Other common side effects include:
Varenicline is a potent medication that requires careful medical supervision. It is essential to understand that while varenicline is highly effective for smoking cessation, it can affect the central nervous system and cardiovascular health. Patients should be screened for a history of psychiatric illness and kidney disease before starting the drug.
As of 2026, there are no FDA black box warnings for Varenicline. The previous black box warning regarding neuropsychiatric events was removed by the FDA in 2016 after large-scale clinical data (the EAGLES study) showed the risk was comparable to other cessation methods and the benefits of quitting smoking outweighed the risks. However, serious warnings remain in the standard precautions section.
There are no absolute 'contraindicated' drug-drug combinations listed by the FDA where the interaction is guaranteed to be fatal; however, the use of Nicotine Replacement Therapy (NRT) alongside varenicline is generally discouraged unless under strict medical supervision.
There is one primary absolute contraindication for varenicline:
These are conditions where the medication may be used, but only after a careful risk-benefit analysis by a healthcare provider:
Varenicline was previously classified under FDA Pregnancy Category C. There are no adequate and well-controlled studies of varenicline in pregnant women. Animal studies have shown some evidence of reduced fetal weight at high doses. However, smoking during pregnancy is a major risk factor for low birth weight, premature birth, and placental abruption. Healthcare providers must weigh the risks of the medication against the known, severe risks of continued tobacco use. If a woman becomes pregnant while taking varenicline, she should notify her doctor immediately to discuss whether to continue or switch to behavioral therapy.
It is not known whether varenicline is excreted in human breast milk, although animal studies suggest that it is. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants, 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.
As noted previously, varenicline is not recommended for patients under 18 years of age. In clinical trials of adolescents, the drug did not show superior efficacy to placebo and the safety profile was not sufficiently established for this population. Smoking cessation in minors is typically managed with behavioral interventions and, occasionally, NRT under specialist guidance.
Varenicline is a small molecule that acts as a partial agonist at the α4β2 neuronal nicotinic acetylcholine receptors. It binds with high affinity and selectivity to these receptors. As a partial agonist, it stimulates the receptor to a level that is approximately 30-60% of the maximum response produced by nicotine. This moderate stimulation results in a sustained release of mesolimbic dopamine, which alleviates the symptoms of nicotine withdrawal. Simultaneously, because varenicline occupies the receptor site with higher affinity than nicotine, it prevents nicotine from binding, thereby acting as a competitive antagonist. This blocks the 'reward' pathway that would otherwise be triggered by smoking a cigarette.
The pharmacodynamic effect of varenicline is characterized by its ability to reduce the 'urge to smoke' and the 'satisfaction from smoking.' The dose-response relationship is well-established, with 1 mg twice daily providing the optimal balance of efficacy and tolerability. Tolerance to the drug's therapeutic effects does not typically develop over the 12-to-24-week treatment period.
Common questions about Varenicline
Varenicline is a prescription medication used to help adults quit smoking cigarettes. It works by targeting the nicotinic receptors in the brain to reduce the physical cravings for nicotine and ease the symptoms of withdrawal. Additionally, it blocks the pleasurable sensations that people usually feel when they smoke, making it less satisfying if a person slips up. It is most effective when used as part of a structured program that includes counseling and support. It is not intended for use in children or for non-smokers.
The most common side effect reported by patients is nausea, which affects about 30% of users and is often managed by taking the pill with food and water. Many people also experience vivid, unusual, or strange dreams and difficulty sleeping (insomnia). Other frequent side effects include headaches, constipation, and gas. Most of these symptoms are mild to moderate and tend to decrease as the body adjusts to the medication over the first few weeks. If side effects become severe, you should contact your healthcare provider to discuss a dose adjustment.
You should be very cautious with alcohol while taking Varenicline, as the medication can change how your body reacts to it. Some patients have reported becoming intoxicated much faster than usual or experiencing unusual aggression and memory 'blackouts' after drinking. The FDA recommends that patients decrease the amount of alcohol they drink until they know how the medication affects them. If you experience any strange behavior or a significant change in your alcohol tolerance, stop drinking and consult your doctor. For many, it is safest to avoid alcohol entirely during the quit attempt.
The safety of Varenicline during pregnancy has not been fully established, as there are no comprehensive studies in pregnant women. While animal studies showed some risks at very high doses, the primary concern is the known danger that smoking poses to a developing fetus. Because smoking causes low birth weight and other complications, a doctor must decide if the benefit of quitting with Varenicline outweighs the potential risks of the drug. Most guidelines suggest trying behavioral therapy or other methods first. Always inform your doctor immediately if you are pregnant or planning to become pregnant.
Varenicline begins to work within the first few days of treatment as it starts to bind to the nicotinic receptors in your brain. However, it takes about four to seven days of consistent dosing to reach a steady level in your bloodstream. This is why patients are instructed to start the medication at least one week before their planned 'Quit Date.' Most people notice a gradual decrease in the urge to smoke during that first week. The full therapeutic effect in helping you stay quit is usually evaluated over the full 12-week course of treatment.
While Varenicline is not considered an addictive medication, stopping it suddenly can sometimes lead to a temporary increase in irritability or a return of the urge to smoke. About 3% of patients in clinical trials reported these symptoms after finishing their course. For most people, stopping after 12 or 24 weeks is straightforward and does not require a tapering schedule. However, if you are concerned about relapse or withdrawal symptoms, your doctor can provide a plan to slowly decrease the dose. It is important to complete the full course prescribed to ensure the best chance of staying smoke-free.
If you miss a dose of Varenicline, you should take it as soon as you remember, provided it is not very close to the time for your next dose. If your next scheduled dose is only a few hours away, it is better to skip the missed dose entirely and continue with your regular schedule. Never take two tablets at the same time to make up for a missed one, as this significantly increases the risk of experiencing nausea or other side effects. Consistency is key to the medication's success, so try to take it at the same time every day.
Varenicline itself does not typically cause weight gain as a direct side effect of the drug's chemistry. However, many people who quit smoking experience weight gain regardless of the method they use, because nicotine suppresses appetite and increases metabolism. Quitting smoking can also lead to 'oral fixation' where a person eats more to replace the habit of smoking. Some studies suggest that Varenicline may actually help limit the amount of weight gained during the initial quitting phase compared to quitting 'cold turkey.' Maintaining a healthy diet and exercise routine can help manage any weight changes.
Varenicline has very few direct drug-drug interactions because it is not processed by the liver's primary enzyme systems. However, it should not be used with Nicotine Replacement Therapy (like patches or gum) without a doctor's supervision, as this can cause severe nausea. Also, because quitting smoking changes your body's metabolism, the doses of other drugs you take—like insulin, warfarin, or theophylline—may need to be adjusted by your doctor. Always provide your healthcare provider with a complete list of all medications and supplements you are currently taking.
Yes, Varenicline is available as a generic medication in many countries, including the United States. Generic versions contain the same active ingredient and meet the same FDA standards for safety and effectiveness as the original brand-name drug (Chantix). The availability of a generic has made the treatment significantly more affordable for many patients. Your pharmacist can help determine if a generic version is available under your specific insurance plan. Regardless of whether you take the brand or the generic, the dosing instructions and safety precautions remain exactly the same.
Other drugs with the same active ingredient (Varenicline)
> Warning: Stop taking Varenicline and call your doctor immediately if you experience any of these serious symptoms:
Varenicline is generally not intended for long-term use beyond 24 weeks. There is little evidence of long-term organ toxicity; however, the primary concern with prolonged use is the potential for persistent sleep disturbances or the masking of underlying psychiatric conditions. Most side effects resolve within days to weeks after discontinuing the medication.
Historically, varenicline carried a Boxed Warning regarding serious neuropsychiatric events. However, following the results of the EAGLES trial (a massive study of over 8,000 smokers), the FDA removed the Boxed Warning in December 2016. The trial demonstrated that while these side effects can occur, the risk is lower than previously feared and must be weighed against the significant health benefits of quitting smoking. Current labeling still contains a 'Warnings and Precautions' section for neuropsychiatric events, but it is no longer a Black Box warning.
Report any unusual symptoms to your healthcare provider. Monitoring your mood and behavior is a critical part of the treatment process.
Varenicline may cause dizziness, somnolence (sleepiness), or sudden loss of consciousness. Do not drive, operate heavy machinery, or engage in potentially dangerous activities until you know how varenicline affects you. Several accidents have been attributed to the sedative effects of the drug.
Varenicline may change the way your body reacts to alcohol. Some patients have reported increased intoxication, unusual aggressive behavior, or 'blackouts' (memory loss) while drinking alcohol during varenicline treatment. It is strongly advised to significantly reduce or eliminate alcohol consumption until you understand your tolerance while on this medication.
Abruptly stopping varenicline does not typically cause a 'withdrawal syndrome' like benzodiazepines or opioids. However, some patients (about 3%) report increased irritability or a return of smoking urges if the drug is stopped suddenly. In some cases, a doctor may suggest a brief taper, though the standard 12-week course is usually sufficient for most to stop without a taper.
> Important: Discuss all your medical conditions, especially kidney disease and mental health history, with your healthcare provider before starting Varenicline.
There are no known interactions between varenicline and specific foods. Unlike some medications, it does not interact with grapefruit juice or dairy products. Taking varenicline with a large meal is actually recommended to improve tolerability and reduce gastrointestinal distress.
Varenicline is not known to interfere with common laboratory tests (such as basic metabolic panels or complete blood counts). It does not cause false positives on standard urine drug screens for substances of abuse.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking, especially those for asthma, diabetes, or blood thinning.
There is no known cross-sensitivity between varenicline and other smoking cessation aids like bupropion or nicotine replacement products. However, patients who have experienced severe skin reactions to other medications should be monitored closely when starting any new drug therapy.
> Important: Your healthcare provider will evaluate your complete medical history, including your kidney function and mental health status, before prescribing Varenicline.
Clinical studies of varenicline did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. However, varenicline is known to be substantially excreted by the kidney. Since 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. The risk of dizziness and falls should also be considered in the elderly population.
For patients with severe renal impairment (estimated creatinine clearance < 30 mL/min), the recommended starting dose is 0.5 mg once daily. The dose may then be increased to a maximum of 0.5 mg twice daily. For patients with end-stage renal disease undergoing hemodialysis, a maximum dose of 0.5 mg once daily may be administered if it is well tolerated.
Because varenicline is not significantly metabolized by the liver, its pharmacokinetics are not affected by liver disease. No dosage adjustments are necessary for patients with any degree of hepatic impairment.
> Important: Special populations require individualized medical assessment. Always inform your doctor if you are pregnant, planning to become pregnant, or have any history of kidney disease.
| Parameter | Value |
|---|---|
| Bioavailability | ~90% |
| Protein Binding | < 20% |
| Half-life | ~24 hours |
| Tmax | 3 to 4 hours |
| Metabolism | Minimal (<10%) |
| Excretion | Renal (92% unchanged) |
Varenicline is the first member of the 'benzazepine' class used specifically for nicotinic receptor modulation in smoking cessation. It is distinct from the 'antidepressant' class (which includes bupropion) and the 'nicotine replacement' class. Its unique pharmacology makes it a first-line therapy in many global clinical guidelines for tobacco use disorder.