Chantix (varenicline)

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Brand Name

Chantix {Pfizer}

Generic Name

varenicline, pronounced ver EN e kleen

Also Known As



What is Chantix?

Chantix is a medication that is used to help people quit smoking. This medication does not contain nicotine, however, it binds to the nicotine receptors in your brain. Chantix works in your brain to block the pleasurable effects of smoking, and also helps to decrease your desire to keep smoking. Chantix may also be used for purposes not described in this medication guide.


Key Facts About Chantix

Any medications that you currently take may need to be adjusted once you quit smoking and start taking Chantix. Be sure to tell your doctor about all of the medications you use, especially insulin, blood thinners, or asthma medications.

Stop using Chantix and call your doctor at once if you have any mood or behavior changes, confusion, anxiety, panic attacks, hallucinations, extreme fear, or if you feel impulsive, agitated, aggressive, restless, hostile, depressed, hyperactive (mentally or physically), or have thoughts about suicide or hurting yourself

Be aware that Chantix may impair your reactions or thinking. You should be careful when driving or doing anything which requires you to be alert, especially when you first start Chantix.

Chantix is in FDA pregnancy category C. It is not known whether Chantix will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while taking Chantix. You should not breast-feed while taking Chantix, as it is known if Chantix can pass into breast milk and may harm a nursing baby.

Chantix should not be given to anyone under the age of 18.


Before You Take Chantix

If you are allergic to varenicline you should not take Chantix.

Let your doctor know if you have or ever have had a mental illness or depression before you start taking Chantix.

If you have heart disease, circulation problems, kidney disease or are on dialysis you should tell your doctor before starting treatment with Chantix.

You should not take other smoking cessation aids or medications while taking Chantix.


Chantix Drug Interactions

You should inform your doctor if you are taking any of the following:

  • asthma medications like theophylline (Respbid, Theobid, Theoclear, Theo-Dur, Uniphyl)
  • insulin
  • warfarin (Coumadin)

Other drugs you take that are not listed may interact with Chantix. You should tell your doctor about all of the medications you use. This includes prescription drugs, vitamins, supplements and herbal products, and over the counter medications. You should not begin taking a new medication without telling your doctor first.


Directions for Taking Chantix

You should take Chantix exactly as prescribed by your doctor. Do not take Chantix in larger or smaller amounts, or for shorter or longer than recommended. Follow the directions on your prescription label. By taking Chantix regularly you increase the chances of this medication’s success.

There are 2 ways that you can begin your treatment with Chantix. Your doctor can help you decide which method is best for you. The first way is to set a date to quit smoking and begin taking Chantix one week before that date. This allows Chantix to build up in your body. The second option is to start taking Chantix before you set a planned quit date. Once you begin taking the Chantix you can choose a quitting date that is between 8 and 35 days after you start treatment.

Be sure to follow through and quit smoking on your planned quit date.

Chantix should be taken after eating and with a full glass of water.

Your dose of Chantix will start out low and gradually increase over the first several days of treatment. You should follow your doctor’s dosing instructions very carefully.

The typical treatment with Chantix is 12 weeks. Your doctor may recommend that you use a second 12-week course to improve the chance that you will quit smoking long-term.

Chantix needs to be stored at room temperature, and away from light, moisture and heat.

If you miss a dose of Chantix you should attempt to take the missed dose as soon as you remember. However, if it is almost time for your next scheduled dose do not take the missed dose in addition to your regular dose.


Chantix Side Effects

If you experience any of the following adverse effects you should stop taking Chantix and seek emergency medical help immediately:

  • allergic reaction such as breathing difficulties, hives, swelling of your face, lips, throat or tongue
  • aggressive, agitated or hostile behavior
  • anxiety or panic attacks
  • bleeding or bruising easily or more often, blood in your urine or stools, and coughing up blood or vomit that looks like coffee grounds
  • blistering skin rash, even if mild
  • chest pain or pressure with a tight feeling in your neck or jaw, pain that spreads to your arm or shoulder, vomiting, sweating, and a general ill feeling
  • depression
  • light headed and short of breath
  • restlessness or hyperactivity
  • sore throat, headache and fever with a skin reaction that is severe with blistering and peeling
  • sudden numbness or weakness, particularly on one side of your body
  • suicidal thoughts or thought about hurting yourself
  • unusual thoughts or behavior

Less serious side effects of Chantix may include:

  • constipation
  • dry mouth or unpleasant taste in your mouth
  • gas
  • headache
  • indigestion
  • nausea (may be for several months)
  • sleep problems or unusual dreams
  • stomach pain
  • tired feeling
  • weakness

It should be noted that this is not a complete list of possible side effects of Chantix. You should contact your physician for a complete list and medical advice regarding these effects.


Chantix Description and Dosing

Chantix is available in capsular, biconvex tablets. The 0.5 mg tablet is white to off-white, and is debossed with “Pfizer” on one side and “CHX 0.5” on the other side.)

The 1 mg tablet is light blue, and is debossed with “Pfizer” on one side and “CHX 1.0” on the other side.

Your doctor will tell you what dose of Chantix is right for you. You should follow your doctor’s instructions exactly. Do not alter or change your dosage of Chantix without talking to your doctor first.

If you suspect that you have overdosed with Chantix you should seek emergency help immediately.


Ingredients in Chantix

The primary active ingredient in Chantix is varenicline. Inactive ingredients in Chantix include microcrystalline cellulose, anhydrous dibasic calcium phosphate, croscarmellose sodium, colloidal silicon dioxide, magnesium stearate, Opadry® White (for 0.5 mg), Opadry® Blue (for 1 mg), and Opadry® Clear.

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The information contained in this drug guide is intended as an educational resource only. This guide is not exhaustive and does not contain all available information about this drug.This guide is not intended as medical advice for individual conditions or treatment.

The information provided in this guide does not replace the need for the advice and services of medical professionals or the need for medical examination. Always talk to your physician or pharmacist before taking any prescription medication or over the counter drugs (including any supplements) or before making any changes to your treatment. Only your doctor, nurse or pharmacist can provide you with safe and effective advice regarding your drug treatment.

The use of the information in this guide is at your sole risk. This information is provided "AS IS" with no warranties to accuracy or timeliness.

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