Brand Names: Chantix

Generic Name: varenicline (Pronunciation: ver EN e kleen)

• What is varenicline (Chantix)?
• What are the possible side effects of varenicline (Chantix)?
• What is the most important information I should know about varenicline (Chantix)?
• What should I discuss with my health care provider before taking varenicline (Chantix)?
• How should I take varenicline (Chantix)?
• What happens if I miss a dose (Chantix)?
• What happens if I overdose (Chantix)?
• What should I avoid while taking varenicline (Chantix)?
• What other drugs will affect varenicline (Chantix)?
• Where can I get more information?

What is varenicline (Chantix)?

Varenicline is a smoking cessation medicine. It is used together with behavior modification and counseling support to help you stop smoking.

Varenicline may also be used for purposes not listed in this medication guide.

Chantix 0.5 mg

oblong, white, imprinted with Pfizer, CHX 0.5

Chantix 1 mg

oblong, blue, imprinted with Pfizer, CHX 1.0

What are the possible side effects of varenicline (Chantix)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using this medication 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.

Your family or other caregivers should also be alert to changes in your mood or behavior.

Call your doctor at once if you have any of these other serious side effects:

• chest pain or pressure, tight feeling in your neck or jaw, pain spreading to your arm or shoulder, vomiting, sweating, general ill feeling;
• feeling light-headed or short of breath;
• sudden numbness or weakness, especially on one side of the body;
• sudden severe headache, confusion, problems with vision, speech, or balance;
• easy bruising, unusual bleeding, blood in your urine or stools, coughing up blood or vomit that looks like coffee grounds;
• fever, sore throat, and headache with a severe blistering, peeling, and red skin rash; or
• the first sign of any blistering type of skin rash, no matter how mild.

Less serious side effects may include:

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

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the Chantix (varenicline) Side Effects Center for a complete guide to possible side effects »

What is the most important information I should know about varenicline (Chantix)?

Before using varenicline, tell your doctor if you have heart disease, circulation problems, kidney disease, or a history of depression or mental illness.

You may choose from 2 ways to use varenicline. Ask your doctor which of the following methods is best for you:

After you stop smoking, the doses of any medications you are using may need to be adjusted. Tell your doctor about all other medicines you use, especially insulin, blood thinners, or asthma medication.

Varenicline may impair your thinking or reactions. You may also have mood or behavior changes when you quit smoking. Until you know how varenicline and the smoking cessation process is going to affect you, be careful if you drive or do anything that requires you to be cautious and alert.