Tobacco – World Health Organization
Chantix – It Does work. Here is my story
What is Chantix?
Varenicline, known by its trade name Chantix, is the most recent medication that is FDA approved to treat smoking addiction. It is available by prescription only. Currently there is no generic form. Varenicline is a partial agonist to a subtype of the nicotinic acetylcholine receptor. A partial agonist is a compound that both stimulates and inhibits the receptor to a mild degree, thereby eliminating any withdrawal effects associated with smoking cessation, but also eliminating the possibility of deriving any additional pleasure from smoking.
It therefore acts like a thermostat, stimulating the receptor when nicotine levels are low and blocking the receptor when nicotine levels are high.
Varenicline was developed by Pfizer through modifying the structure of cytisine, a chemical found in a variety of plants that is known to be a nicotine receptor agonist and has been used as a smoking cessation aid in its own right in Eastern Europe for at least 40 years. Varenicline was fast tracked by the U.S. Food and Drug Administration in February 2006, shortening its approval from 10 to 6 months because of its demonstrated effectiveness in clinical trials and perceived lack of safety issues. The FDA approved varenicline on May 11, 2006, which became available in the U.S. public August 1, 2006 and in the European Union September 29, 2006.
Varenicline comes as a tablet to be taken by mouth. It is usually taken once or twice daily with a full glass of water after eating.
Group support programs or individual counseling are strongly recommended as an adjunct to the medication regime. Directions:
• Your doctor will probably start you on a low dose of varenicline and gradually increase the dose over the first week of treatment.
• Set a quit date to stop smoking, and start taking varenicline one week before that date. You may continue to smoke during this first week, but stop smoking on the quit date. 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 will still be able to stop smoking.
• Continue to take varenicline for 12 weeks.
• If you have completely stopped smoking at the end of the 12 weeks, your doctor may tell you to take varenicline for another 12 weeks. Continuing to take varenicline may ensure that you will not start to smoke again.
• Once you have stopped smoking, your doctor may need to change the doses of some of your other medications.
• If you have not stopped smoking at the end of 12 weeks, tell your doctor so he or she can help you to understand why you were not able to stop smoking and make plans for you to try to quit again. Do not use varenicline with other smoking cessation products.
• Varenicline may make you drowsy. Do not drive a car or operate machinery.
• If you 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 the missed one.
• Do NOT drink alcohol while taking this medication.(However, instructions on the package may not specify if you can drink any alcohol while taking this prescription.)
Call your doctor if you experience any of the following side effects: thinking about harming or killing yourself, planning or trying to do so, or thinking about harming someone else; changes in your usual thoughts, mood, or behavior. Call your doctor immediately and report it to: The Food and Drug Administration’s (FDA) Medwatch Adverse Event Reporting program online (at http://www.fda.gov/MedWatch/report.htm).
What is the suicide risk associated with the anti-smoking drug Chantix?
In November 2007, a year and three months after varenicline became available to the American public, the FDA announced it had received reports that patients using it for smoking cessation had experienced several serious psychological symptoms, including suicidal ideation and occasional suicidal and agitated behavior. On February 1, 2008, the FDA issued an alert, noting that “it appears increasingly likely that there is an association between varenicline and serious neuropsychiatric symptoms.”
As of February 2008, 491 cases of suicidal thinking or behavior were reported, including 420 in the United States. Thirty-nine of the 491 cases resulted in suicide, including 34 in the United States. More than 6 million people have been prescribed the pill since it was launched. When considering the number of prescriptions, the risks of serious psychological symptoms are extremely low, and the risk that those symptoms will result in death is even lower. When weighing such risks against the risks of continued smoking, varenicline actually ends up being safer than continued tobacco use.
Sorting out the cases individually in order to determine what role, if any, varenicline has in contributing to or even causing these symptoms remains a daunting task. One of the more celebrated cases, the case of Carter Albrecht who was shot by his neighbor after striking his girlfriend and entering his neighbor’s house, was probably due to mixing the drug with large amounts of alcohol. Suicidal thinking is a complex behavior with multiple contributing factors, including personality, mood, environment, history, and other substance or prescription medication use. But the end result is often extremely tragic and traumatic, prompting public outcry and a large amount of press. It is important to keep these issues in mind when considering the risks of using this medication against the risks of continuing to smoke.
What other non-NRT medication therapies are available, if any?
A number of other medications have been studied, but only two are currently recommended as second-line therapies, should individuals either fail the first-line therapies or experience side effects that contraindicate future use. It is important to remember when selecting medications that prior failure with a medication does not predict future failure. Thus, second-line therapies are generally used when first-line therapies are contraindicated or some other compelling clinical reason suggests their trial over a first-line therapy. An example would be for those who have migraines in addition to tobacco dependence, where the clinician would suggest trying nortriptyline as a first-line therapy because it is commonly used to treat migraine headaches. Additionally, there is some evidence demonstrating that women tend to have poor response rates to NRTs and therefore non-NRT medications should be considered, such as bupropion, varenicline, nortriptyline, and clonidine.
The other medications that have been extensively studied, which have not been found to be successful include selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, paroxetine, citalopram, etc., and naltrexone (ReVia). Tobacco dependence is a common problem with depression, and treating the depression can assist the patient in following through with a smoking cessation program. While SSRIs can be used in conjunction with the other smoking cessation medications to treat depression, their use as standalone agents is not effective.
Naltrexone has been found to be effective in treating alcoholism in order to assist in abstinence and decrease craving. Naltrexone acts by blocking opiate receptors, but it is not helpful in decreasing craving for cigarettes. Other medications that have not been found to be helpful include benzodiazepines, beta-blockers, silver acetate, and mecamylamine. Mecamylamine is a nicotine antagonist that may prove useful in boosting the effectiveness of antidepressants, but it is too early to tell if this medication will actually pan out.
Two medications that have proven to be effective as second-line therapies include the tricyclic antidepressant, nortriptyline (trade name, Pamelor), and the antihypertensive, clonidine. Nortriptyline blocks the transporter pump and prevents the reuptake of norepinephrine, thus increasing levels of this neurotransmitter in the brain. Norepinephrine release is stimulated by nicotine, so that nortriptyline may aid as an indirect replacement therapy through this action. Clonidine is a more complicated medication. It generally reduces what is called sympathetic tone-that is, it reduces the “fight or flight response” by reducing the release of norepinephrine. Clonidine is used not only to reduce blood pressure, but also to treat neuropsychiatric conditions such as Tourette’s disorder and ADHD (attention deficit hyperactivity disorder). It is also used to reduce the effects of opiate withdrawal in opiate-dependent patients. Clonidine, in a sense, does the exact opposite of nortriptyline, demonstrating the underlying complexity of nicotine addiction and how oversimplified our current theories are about this drug and its effects on the brain and body.
Term:
Partial agonist-A chemical (such as a drug) that can both block and stimulate a receptor depending upon the relative amount of neurotransmitter present in the synaptic cleft. If the amount of neurotransmitter is large, the chemical acts as an antagonist and if the amount of neurotransmitter is low, the chemical acts as an agonist.
When considering the number of prescriptions, the risks of serious psychological symptoms are extremely low, and the risk that those symptoms will result in death is even lower.
