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varenicline varenicline

 
  Trade/other name(s)
Chantix, Champix 		 
  Pronunciation: Var-EN-uh-kleen  
  Why would this drug be used?
Varenicline is used to help people quit smoking. 		 
  How does this drug work?
Varenicline binds to the nicotine receptors in the brain, and blocks them so that nicotine cannot bind to them. The reward of nicotine is reduced because nicotine can no longer stimulate the pleasure center by raising the dopamine level in the brain. This helps reduce cravings for cigarettes. It also seems to help reduce withdrawal symptoms when smokers quit. 		 
  Before taking this medicine

Tell your doctor: 		 
 
  • If you are allergic to any medicines, dyes, additives, or foods.
  • If you have serious medical problems, especially kidney disease.
  • If you have ever had depression, bipolar illness, schizophrenia, or other serious mental health problems. Varenicline has not been tested in people with these illnesses, and can make them worse.
  • If you are pregnant, trying to get pregnant, or if there is any chance of pregnancy. Although studies in pregnant animals show no problems, studies in pregnant women have not been done. Varenicline may be used only if the potential benefit outweighs the risk to the fetus.
  • If you are breast-feeding. Some animal studies have shown that varenicline may be transferred to nursing pups. While no human studies have been done, this drug may pass into breast milk and affect the baby. Talk with your doctor about the possible risks of breast-feeding while taking this drug.
  • About any other prescription or over-the-counter medicines you are taking, including vitamins and herbs.
 
  Interactions with other drugs
No major drug interactions are known at this time. You may want to check with your doctor, nurse, or pharmacist about any new information on medicines, vitamins, herbs, and supplements, and whether alcohol can cause problems with this medicine. 		 
  Interactions with foods
No serious interactions with foods are known at this time. Check with your doctor, nurse, or pharmacist about whether foods or alcohol may be a problem. 		 
 
Tell all the doctors, dentists, nurses, and pharmacists you visit that you are taking this drug.

  
  How is this drug taken or given?
Varenicline is a pill. It should be taken after a meal, with a full glass of water. For the first 3 days, the dose consists of a single 0.5 milligram (mg) tablet. For the next 4 days, one 0.5 mg tablet should be taken each morning and evening. Starting with the second week, the dose is one 1 mg tablet each morning and evening. Some people have problems with this higher dose. In that case, a lower dose may be used.

Varenicline is given for 12 weeks. People who are able to quit smoking during this period may continue to receive another 12 weeks of treatment to improve their chances of staying quit. Those who have not been able to quit during the first 12 weeks may want to address any factors that made it harder for them to quit, and try again after that.

 
  Precautions
Some people have nausea and trouble sleeping at first, which usually goes away on its own. However, if you keep being troubled by these symptoms, talk with your doctor. You may do better on a lower dose of the drug.

Some people have reported emotional changes such as depressed mood, agitation, changes in behavior (including hostility and aggressiveness), suicidal thoughts, and even suicide while using varenicline to try and quit smoking. If you have any of these symptoms, stop taking the drug and contact your doctor right away.

Tell family members, loved ones, and caregivers when you plan to start taking this drug. They should know to contact your doctor right away for mood and behavior problems. This is important, since another person may be able to better see changes that are not caused by nicotine withdrawal.

It is not unusual to feel irritable, anxious, somewhat depressed, or have trouble sleeping when you are withdrawing from nicotine, whether or not you take varenicline.

Use caution when driving or using dangerous machinery until you know varenicline will affect you.

 
 
Possible side effects
  
  Common
  • Nausea*
 
  Less common
  • Headache
  • Trouble sleeping*
  • Vivid, strange, or unusual dreams
 
  Rare
  • Change in how things taste
  • Vomiting
  • Abdominal pain
  • Upset stomach
  • Flatulence (gas)
  • Constipation
  • Depressed mood*
  • Agitation, restlessness*
  • Change in behavior, including hostility and aggressiveness*
  • Thoughts of suicide, suicide attempts*

*See "Precautions" section for more detailed information.

  
 
There are other side effects not listed above that can also occur in some patients. Tell your doctor or nurse if you develop these or any other problems.
  
 
 
  FDA approval
Yes – first approved in 2006. 		 
 
 
  Disclaimer: This information does not cover all possible uses, actions, precautions, side effects, or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for talking with your doctor, who is familiar with your medical needs.  


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