Varenicline | Side Effects, Dosage, Uses & More
Advertisement

Generic Name:

varenicline, Oral tablet

All Brands

  • Chantix
SECTION 1 of 5

Highlights for varenicline

Oral tablet
1

Varenicline is a short-term drug used to help you quit smoking.

2

This drug comes in the form of a tablet you take by mouth.

3

Varenicline is only available as the brand-name drug called Chantix. It isn’t available as a generic drug.

4

The more common side effects of this drug include nausea, vomiting, gas, constipation, and sleep problems (vivid, unusual, or strange dreams).

5

Varenicline may lead to serious mental health problems. These include depression or thoughts and behaviors of hurting yourself. You should stop taking this drug and call your doctor right away if you feel agitated, hostile, or depressed, or have any other unusual changes in your behavior.

IMPORTANT INFORMATION

FDA warning

This drug has a black box warning. This is the most serious warning from the Food and Drug Administration (FDA). A black box warning alerts doctors and patients about drug effects that may be dangerous.

Mental health problems warning. Varenicline may cause new or worse mental health problems. These include depression or thoughts and behaviors of hurting yourself. You and your doctor should watch for signs of mental health problems. These include feeling agitated, hostile, depressed, or any other unusual changes in your behavior. You should stop taking this drug and call your doctor right away if you or your caregiver notices these symptoms.

Nicotine withdrawal

Trying to quit smoking, with or without using this drug, may cause nicotine withdrawal. Symptoms include an urge to smoke, trouble sleeping, irritability, frustration, anger, anxiety, trouble concentrating, restlessness, slower heart rate, increased appetite, weight gain, or new or worsening mental health problems (such as depression).

Alcohol interaction

Varenicline can increase the effects of alcohol in your body. The use of drinks that contain alcohol may increase your risk of aggression while you’re taking this drug. If you drink alcohol, talk to your doctor. You should reduce your alcohol intake until you know how this drug affects your tolerance for alcohol.

Hypersensitivity (allergic) reactions

This drug may cause severe allergic reactions. Symptoms include swelling of your face, mouth, neck, arms, or legs. If you have these symptoms, stop taking this drug and seek medical help right away.

Drug features

Varenicline is a prescription drug. Varenicline is available as an oral tablet.

Varenicline is only available as a brand-name drug called Chantix. It isn’t available as a generic drug.

Why it's used

Varenicline is a short-term drug used to help you quit smoking.

How it works

Varenicline belongs to a class of drugs called nicotinic receptor partial agonists.

More Details

How it works

Varenicline belongs to a class of drugs called nicotinic receptor partial agonists. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions. 

Varenicline works by affecting the nicotine receptors in your brain. Smoking stimulates these nicotine receptors and creates a feeling of satisfaction. This drug prevents the stimulation of nicotine receptors. This lessens your cravings and reduces your desire to smoke.

Advertisement
SECTION 2 of 5

varenicline Side Effects

Oral tablet

More Common Side Effects

The more common side effects of varenicline can include:

  • nausea

  • vomiting

  • gas

  • constipation

  • sleep problems, such as vivid, unusual, or strange dreams

If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious Side Effects

Call your doctor right away if you have serious side effects. Call 9-1-1 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:

  • Mental health problems. Symptoms can include:

    • thoughts of hurting yourself or dying
    • attempts to hurt yourself
    • new or worse depression, anxiety, or panic attacks
    • feeling very agitated or restless
    • acting aggressive, angry, or violent
    • acting on dangerous impulses
    • mania (extreme increase in activity and talking)
    • abnormal thoughts or sensations
    • hallucinations (seeing or hearing things that aren’t there)
    • paranoia (feeling like people are against you)
    • confusion
    • other unusual changes in behavior or mood
  • Heart problems. Symptoms can include:

    • chest discomfort (uncomfortable pressure, squeezing, fullness, or pain) that lasts more than a few minutes or that goes away and comes back
    • pain or discomfort in one or both of your arms, back, neck, jaw, or stomach
    • shortness of breath, sweating, nausea, vomiting, or lightheadedness with chest discomfort
  • Allergic reactions. Symptoms can include:

    • trouble breathing
    • swelling of your face, mouth (tongue, lips, or gums), throat, neck, arms, or legs
  • Serious skin reactions. Symptoms can include:

    • skin rash
    • hives
    • swelling, redness, blistering, or peeling of your skin
    • painful sores in your mouth
  • Nicotine withdrawal. Trying to quit smoking, with or without using this drug, may cause nicotine withdrawal. Symptoms can include:

    • urge to smoke
    • depression
    • trouble sleeping
    • irritability
    • frustration
    • anger
    • anxiety
    • trouble concentrating
    • restlessness
    • slower heart rate
    • increased appetite
    • weight gain
    • worsening of mental health problems that you already have, such as depression
Pharmacist's Advice
Healthline Pharmacist Editorial Team

Varenicline may cause you to feel sleepy, dizzy, or have trouble concentrating. You shouldn’t drive, use machinery, or do other tasks that require alertness until you know how this drug affects you.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.
SECTION 3 of 5

varenicline May Interact with Other Medications

Oral tablet

Varenicline can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.

To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Alcohol interaction

Varenicline can increase the effects of alcohol in your body. The use of drinks that contain alcohol may also increase your risk of aggression while you’re taking this drug. If you drink alcohol, talk to your doctor. You should reduce your alcohol intake until you know how this drug affects your tolerance for alcohol.

Medications that might interact with this drug

Drugs that should not be used with varenicline
  • Bupropion. This drug is also used to help you quit smoking. It isn’t known if it’s safe to take varenicline and bupropion together.

Drugs that increase the risk of side effects

Taking varenicline with certain drugs may cause more side effects. These drugs include:

  • Nicotine replacement therapy, such as gum, inhalers, lozenges, nasal sprays, and skin patches. Taking these drugs together may cause nausea, vomiting, upset stomach, headache, dizziness, and tiredness.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.

People with mental health problems

Quitting smoking, with or without using this drug, can cause or worsen mental health problems. Varenicline can also cause or worsen mental health problems. Let your doctor know if you have a history of depression or other mental health problems before taking this drug.

People with seizures

This drug can cause or worsen seizures. Let your doctor know if you have a history of seizures.

People with heart problems

This drug can cause or worsen heart problems. Let your doctor know if you have any heart or blood vessel problems. Seek medical help right away if you have symptoms of a heart attack. These include chest discomfort, pain in your arm(s), back, neck, jaw, or stomach, or shortness of breath, sweating, nausea, vomiting, or lightheadedness with chest pain.

People with kidney problems or who are on dialysis

If you have severe kidney problems, you may not be able to clear this drug from your body well. This may increase the levels of varenicline in your body and cause more side effects. Your doctor may give you a lower dose of this drug.

Pregnant women

Varenicline is a category C pregnancy drug. That means two things:

  1. Research in animals has shown adverse effects to the fetus when the mother takes the drug.
  2. There haven’t been enough studies done in humans to be certain how the drug might affect the fetus. 

Talk to your doctor if you’re pregnant or planning to become pregnant. This drug should only be used if the potential benefit justifies the potential risk to the fetus.

Women who are breast-feeding

Varenicline may pass into breast milk and may cause side effects in a child who is breast-fed.

Talk to your doctor if you breast-feed your child. You may need to decide whether to stop breast-feeding or stop taking this medication.

For seniors

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects.

For children

This medication hasn’t been studied in children. It shouldn’t be used in people younger than 18 years.

Allergies

Varenicline can cause a severe allergic or skin reaction. Symptoms can include:

  • trouble breathing
  • swelling of your face, mouth (tongue, lips, or gums), throat, or neck
  • rash with peeling skin
  • blisters in your mouth 

If you have an allergic reaction, call your doctor or local poison control center right away. If your symptoms are severe, call 9-1-1 or go to the nearest emergency room.

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal (cause death).

SECTION 4 of 5

How to Take varenicline (Dosage)

Oral tablet

All possible dosages and drug forms may not be included here. Your dosage, drug form, and how often you take the drug will depend on:

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

What are you taking this medication for?

Smoking cessation

Brand: Chantix

Form: Oral tablet
Strengths: 0.5 mg, 1 mg
Adult dosage (ages 18–64 years)
  • There are 2 ways you can use varenicline. Talk to your doctor about which way is best for you.
    1. You should set a quit date to stop smoking. Start taking varenicline 7 days before your quit date.
    2. Or you can start taking varenicline and then quit smoking between days 8 and 35 of treatment with this drug.
    Starting this drug before your quit date gives it time to build up in your body. You can keep smoking during this time. Take it exactly as prescribed by your doctor.
  • Typical starting dose: Your doctor will slowly increase your dose over time.
    • Days 1–3: 0.5 mg taken once per day.
    • Days 4–7: 0.5 mg taken twice per day.
    • Day 8–end of treatment: 1 mg taken twice per day.
  • Length of treatment: Most people will take this drug for up to 12 weeks. If you’ve completely quit smoking by 12 weeks, your doctor may prescribe this drug for another 12 weeks to help you stay cigarette-free. If you haven’t fully quit smoking by the end of the first 12 weeks, your doctor may adjust your overall treatment to help make it easier for you to quit smoking
Child dosage (ages 0–17 years)

This medication hasn’t been studied in children. It shouldn’t be used in people younger than 18 years of age.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects. Your doctor will carefully choose the dose that’s right for you, especially if you have kidney problems.

Special considerations

Kidney disease: If you have severe kidney problems, the recommended starting dose is 0.5 mg taken once per day. The maximum dose is 0.5 mg taken twice per day. If you’re on dialysis, the maximum dose is 0.5 mg taken once per day.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always to speak with your doctor or pharmacist about dosages that are right for you.
Pharmacist's Advice
Healthline Pharmacist Editorial Team

Varenicline comes with serious risks if you don’t take it as prescribed.

If you stop taking the drug suddenly or don’t take it at all

You may have more trouble quitting smoking. If you don’t stop smoking, it could lead to serious health problems. These include heart or lung disease or certain types of cancers.

If you miss doses or don’t take the drug on schedule

Your medication may not work as well or may stop working completely. For this drug to work well, a certain amount needs to be in your body at all times. Most people need to take varenicline for a few weeks for it to work best.

If you take too much

You could have dangerous levels of the drug in your body. This could lead to more side effects. These include:

  • nausea
  • insomnia
  • headache
  • strange dreams

If you think you’ve taken too much of this drug, call your doctor or local poison control center. If your symptoms are severe, call 9-1-1 or go to the nearest emergency room right away.

What to do if you miss a dose

Take your dose as soon as you remember. If it’s almost time for your next dose, skip the missed dose. Take your next dose at your regular time. Never try to catch up by taking two doses at once. This could result in dangerous side effects.

How to tell if the drug is working

You shouldn’t have as strong of an urge to smoke. Eventually, you should be able to quit smoking.

Varenicline is used for short-term treatment.

Important considerations for taking varenicline
Take varenicline after eating Take varenicline after eating and with a full glass (8 ounces) of water
timing Take this drug at the time(s) recommended by your doctor
can cut or crush You can cut or crush the tablet
storage Store this drug carefully See Details
medication is refillable A prescription for this medication is refillable See Details
travel Travel See Details
Clinical monitoring Clinical monitoring See Details
not usually stocked Not every pharmacy stocks this drug. When filling your prescription, be sure to call ahead
prior authorization required Insurance See Details

Store this drug carefully

  • Store varenicline at room temperature. Keep it between 68°F and 77°F (20°C and 25°C).
  • Don’t store this medication in moist or damp areas, such as bathrooms.

A prescription for this medication is refillable

You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.

Travel

When traveling with your medication:

  • Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
  • Don’t worry about airport x-ray machines. They can’t hurt your medication.
  • You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled box with you.
  • Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.

Clinical monitoring

You and your doctor should monitor certain health issues. This can help make sure you stay safe while you take this drug. These issues include:

  • Kidney function. Your doctor may do blood tests to check how well your kidneys are working. If your kidneys aren’t working well, your doctor may lower your dose of this drug.
  • Mental health and behavioral problems. You and your doctor should watch for any unusual changes in your behavior and mood. This drug can cause new mental health and behavior problems. It can also make problems you already have worse.

Insurance

Many insurance companies require a prior authorization for this drug. This means your doctor will need to get approval from your insurance company before your insurance company will pay for the prescription.

Are there any alternatives?

There are other drugs available to treat your condition. Some may be better suited for you than others. Talk to your doctor about other drug options that may work for you.

What does the pill look like?

Showing - out of 8
SECTION 5 of 5

How Much Does varenicline Cost?

Oral tablet

We've partnered with GoodRx so you can compare prices, find discounts and save up to 80% on your next prescription. Check out the low coupon prices below — no insurance required.

Compare prices and save up to 80% on your next refill!

Lowest price for varenicline

Membership warehouse $300.88
Kroger Pharmacy $301.86
Target (CVS) $309.27
These prices represent the lowest priced national pharmacies for varenicline on GoodRx. They may be lower than your insurance.

Enter your zip code to find the best deal near you.

These prices represent the lowest priced national pharmacies for varenicline on GoodRx. They may be lower than your insurance.

Show Sources

Content developed in collaboration with University of Illinois-Chicago, Drug Information Group

Medically reviewed by Creighton University, Center for Drug Information and Evidence-Based Practice on November 6, 2015

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
Advertisement
Advertisement
Advertisement