Varenicline (Chantix)

Varenicline (Chantix™) is a newer prescription medicine developed to help people stop smoking. It works by interfering with nicotine receptors in the brain. This means it has 2 effects: it lessens the pleasurable physical effects a person gets from smoking, and it reduces the symptoms of nicotine withdrawal.

Several studies have shown varenicline can more than double the chances of quitting smoking. Some studies have also found it may work better than bupropion, at least in the short term.

Varenicline comes in pill form and is taken after meals, with a full glass of water. The daily dose increases over the first 8 days it is taken. The dose starts at one 0.5 mg pill a day for the first 3 days, then the 0.5 mg pill twice a day for the next 4 days. At the start of the second week, the dose is raised to 1 mg each morning and evening. For people who have problems with the higher dose, a lower dose may be used during the quit effort. Varenicline is given for 12 weeks, but people who quit during that time may get another 12 weeks of treatment to boost their chance of staying quit.

Reported side effects of varenicline have included headaches, nausea, vomiting, trouble sleeping, unusual dreams, flatulence (gas), and changes in taste. There have also been more recent reports of depressed mood, thoughts of suicide, attempted suicide, and changes in behavior in people taking varenicline. People who have these problems should contact their doctors right away. These side effects may happen, but varenicline is usually well-tolerated.

Since varenicline is a newer drug, not much research has been done yet to find out if it is safe to use at the same time as nicotine replacement therapy (NRT) products. A recent study has suggested that using varenicline along with NRT is well-tolerated and safe. But the company that makes varenicline noted that people who used the drug along with NRT had more side effects such as nausea and headaches. More research is needed.

Why is this medication prescribed?

Varenicline is used to help people stop smoking. Varenicline is in a class of medications called smoking cessation aids. It works by blocking the pleasant effects of nicotine (from smoking) on the brain.
How should this medicine be used?

Varenicline comes as a tablet to take by mouth. It is usually taken once or twice a day with a full glass of water after eating. Take varenicline at around the same time(s) every day. If you are taking varenicline twice a day, take one dose in the morning and one dose in the evening. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take varenicline exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Your doctor will probably start you on a low dose of varenicline and gradually increase your dose over the first week of treatment.

Set a quit date to stop smoking, and start taking varenicline 1 week before that date. You may continue to smoke during this first week, but make sure to try to stop smoking on the date you have chosen.

It may take several weeks for you to feel the full benefit of varenicline. You may slip and smoke during your treatment. If this happens, you may still be able to stop smoking. Continue to take varenicline and to try not to smoke.

You will probably take varenicline for 12 weeks. If you have completely stopped smoking at the end of 12 weeks, your doctor may tell you to take varenicline for another 12 weeks. This may help keep you from starting to smoke again.

If you have not stopped smoking at the end of 12 weeks, talk to your doctor. Your doctor can try to help you understand why you were not able to stop smoking and make plans to try to quit again.
Other uses for this medicine
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This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
What special precautions should I follow?

Before taking varenicline,

* tell your doctor and pharmacist if you are allergic to varenicline or any other medications.
* tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: anticoagulants ('blood thinners') such as warfarin (Coumadin); insulin; other medications to help you stop smoking such as bupropion (Wellbutrin, Zyban) and nicotine gum, inhaler, lozenges, nasal spray, or skin patches; and theophylline (Theo-24). Your doctor may need to change the doses of some of your medications once you stop smoking.
* tell your doctor if you have or have ever had kidney disease.
* tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking varenicline, call your doctor.
* you should know that varenicline may make you drowsy, dizzy, or have difficulty concentrating. There have been reports of traffic accidents, near-miss accidents, and other types of injuries in people who were taking varenicline. Do not drive a car or operate machinery until you know how this medication affects you.
* ask your doctor for advice and for written information to help you stop smoking. You are more likely to stop smoking during your treatment with varenicline if you get information and support from your doctor.

What special dietary instructions should I follow?


Unless your doctor tells you otherwise, continue your normal diet.
What should I do if I forget a dose?


Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can this medication cause?

Varenicline may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

* nausea
* constipation
* gas
* vomiting
* heartburn
* bad taste in the mouth
* increased or decreased appetite
* trouble falling asleep or staying asleep
* unusual dreams or nightmares
* drowsiness
* headache

Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately:

* swelling of the face, tongue, lips, gums, throat, arms, or legs
* difficulty swallowing or breathing
* rash
* swollen, red, peeling or blistering skin
* blisters in the mouth

Varenicline may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].

What storage conditions are needed for this medicine?


Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose


In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

What other information should I know?


Keep all appointments with your doctor.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

Brand names


* Chantix®