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Generic name: varenicline [ver-EN-e-kleen]
Drug classes: cholinergic agonists, smoking cessation agents

What is Chantix?

Chantix is a medication to help you quit smoking.Chantix can be used in conjunction with counselling and behaviour modification to help you quit smoking.


You may experience nicotine withdrawal symptoms when you quit smoking. This can include feeling restless, depressed, or angry.If you are feeling depressed, agitated, hostile, or aggressive, or if your thoughts include suicide or harming yourself, stop taking Chantix immediately and contact your doctor.Avoid drinking large quantities of alcohol. Varenicline may increase the effects or alter the way that you react to alcohol.

Before you take this drug

If you have used Chantix in the past, and:

  • A serious allergic reaction: difficulty breathing, swelling of your face, neck, or tongue;
  • As with any medication, skin reactions could occur: blisters in your mouth and peeling skin rash.

Tell your doctor about any of the following to ensure that Chantix will be safe for you:

  • Mental illness or depression
  • A seizure;
  • Kidney disease (or dialysis if you have it);
  • Heart or blood vessel disorders;
  • If you are a heavy drinker of alcohol,

Inform your doctor if you are pregnant. Varenicline is not known to harm an unborn child if taken during pregnancy. Smoking while pregnant can cause birth defects or harm to the unborn child.Your baby may vomit or spit more than usual if you are breastfeeding while taking this medication. They may also have seizures.

Chantix cannot be used by anyone under the age of 18.

Similar/related drugs

Bupropion, varenicline, nicotine, zyban, nicotinerette, and Nicoderm CQ

How to take Chantix?

Follow all instructions listed on your prescription label, and read any medication guides or instruction sheets provided with the medication. Read all the instructions on the prescription label.You will start with a small dose of Chantix and gradually increase the dosage over the course of your first few days. To get the best results, take Chantix regularly.There are three ways you can use this medication. You can ask your doctor to tell you the best way for you.

  • Chantix should be taken one week prior to the date you have set for quitting smoking. Be sure to stop smoking by the date you have set. This medicine should be taken for 12 weeks.
  • Chantix should be taken before you decide on a date to quit smoking. The date you choose for quitting should fall between 8 and 35 calendar days after the start of treatment. This medicine should be taken for 12 weeks.
  • Chantix is a medication that helps you reduce your smoking over 12 weeks. Take another 12-week period for a grand total of 24.

Take the medicine after you have eaten. Take the medication with a glass of water.You may experience nicotine withdrawal symptoms when you stop smoking. This can happen with or without the use of varenicline. These symptoms include increased appetite, weight loss, difficulty sleeping, a slower heartbeat, anxiety or restlessness, and the urge to smoke.Quitting smoking can also worsen or cause mental health issues, like depression.If you are feeling depressed, agitated, hostile, or aggressive, or if thoughts of suicide or harming yourself or others have crossed your mind, stop taking the medicine and contact your doctor.Store away from heat and moisture at room temperature.

Details on dosage

Adult dose for smoking cessation:

Days 1 to 3: 0.5 mg once daily orally
Days 4–7: 0.5 mg twice daily.
From days 8 until the end of treatment, take 1 mg twice daily.
The patient should decide on a date by which they will stop smoking. The patient should begin the treatment 1 to 2 weeks prior to this date.
Smoking cessation treatments are more successful when patients are motivated to quit smoking and receive additional support and advice.
In smoking cessation treatment, the risk of relapse is higher in the immediate period following the end.
Quit smoking

What happens if I miss the dose?

If it is almost time for your next dose, skip any missed ones altogether and don't double up on any medication at once.Refill your prescription before you run out.

What happens if I overdose?

Reach out immediately if a poison situation develops by calling 1-800-222-1222 for poison assistance and seeking immediate medical care.

What should be avoided?

Avoid drinking large amounts of alcohol when taking Varenicline. It can alter the way that you react to alcohol. Chantix users may experience unusual behaviour, such as aggression or forgetfulness, when drinking alcohol.You should not take other medications to stop smoking unless you have been told to by your doctor. Chantix can have unpleasant side effects when used with a nicotine patch.Do not drive or participate in hazardous activities until you know how your medicine affects you. You may be unable to react properly.

Side effects of Chantix

If you experience any of the following symptoms: hives, difficulty breathing, swelling on your face or in your throat, or severe skin reactions (fever or sore throat with burning eyes or skin pains, or a red or purple rash that blisters and peels),

If you experience:

  • A seizure (convulsions);
  • Thoughts of suicide or harming yourself
  • Strange dreams, sleepwalking, trouble sleeping;
  • Mental health problems that are new or worsening—changes in mood or behaviour, depression, agitation, hostility, and aggression
  • Heart attack symptoms: chest pain, pressure, or pain that spreads to your shoulder or jaw; nausea; sweating.
  • Stroke symptoms: sudden numbness, weakness, or drooping on one side, or problems with balance or vision.

You or your family members should be aware of any changes in mood or behaviour.

Side effects of Chantix include:

  • Nausea (may persist for several months), vomiting;
  • Constipation, gas;
  • Sleep problems (insomnia);
  • Unusual dreams

There may be other side effects. Call your physician if experiencing side effects; alternatively, reach out to the FDA at 1-800-FDA-1088 in order to report it.

Interaction with other drug

Your doctor may adjust your regular doses of medications after you quit smoking.Inform your doctor of all the medicines you are taking, as well as any new ones. Included are prescription and over-the-counter medicines, vitamins, and herbal products. This list does not include all possible interactions.




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