For years I have had at least one consistent answer to the question, “What is the single most important thing I can do about my health?”
And the answer is, “If you are a smoker, stop. And if you are not a smoker, don’t start.”
But the major barrier for smokers who want to quit, despite all of the news and information about the incredible dangers of cigarette and cigar smoking, is the fact that cigarette and cigar smoke is so incredibly addicting.
Once hooked, many people simply can’t do anything about it. That’s not their fault, given the fact that the nicotine in cigarettes and cigars is one of the most addicting substances we know of.
Today, a new form of targeted therapy has been approved by the Food and Drug Administration that may just be the answer for many chronic smokers who have failed quit attempts in the past.
The name of the drug is varenicline (trade name: Chantix) that has been developed and will be marketed by Pfizer.
The reason so many of us are hopeful about this new medication is because it has a different mechanism of action than other smoking cessation aids such as nicotine patches and gum (which provide the body with nicotine without the dangerous cancer-causing substances found in cigarette smoke), and the medication bupropion (trade name: Zyban) which is an antidepressant that has a particular anti-smoking effect not found in other antidepressants.
Although the mechanism of nicotine addiction is a complex process in our bodies, understanding how it works is relatively simple.
People who smoke become addicted to the nicotine. No cigarette, no nicotine, and about 4-6 hours after your last puff you need another fix.
That is a classic addictive behavior process.
What happens is that we have something called a nicotine receptor that is located in several parts of our brain. According to a recent article in the International Journal of Clinical Practice, there are an increased number of these receptors in the part of our brain that deals with what we can call “pleasurable responses.”
When you inhale nicotine, it travels through your body into your brain and latches on to these receptors. That then stimulates the brain cell to which the receptor is attached to secrete a substance called dopamine. When the amount of dopamine in the spaces around the cells in this part of the brain increases, the smoker feels good.
Voila! Another chronic smoker is introduced to the habit.
As people smoke, according to the author of the article, the number of nicotine receptors in the brain increases, as does the pleasurable response. This is all associated with a “learned behavior” of connecting the functions associated with smoking a cigarette with the sense of pleasure. We learn to relate the opening of the pack of cigarettes and lighting the cigarette with the pleasurable response that is going to follow. And we learn that there are certain things we do, such as smoke while drinking an alcoholic beverage or eating a meal, will also result in the same effect.
This is all very complicated, but the net result is that a number of changes occur in our bodies and our brains that create habits that can be very difficult to change without a very concerted effort.
Varenicline is a new approach to dealing with this problem.
As I mentioned before, we can provide nicotine substitutes and antidepressants. But varenicline is actually a targeted therapy, based on principles similar to the targeted therapies I have discussed in other blogs (for example, Herceptin) except in this case it is targeting a receptor on a nicotine-vulnerable cell as opposed to a cancer cell.
The net effect is the same: block the receptor with varenicline, and the nicotine can’t get to the receptor and can’t cause its triggering effect on the dopamine levels in our brains.
However, varenicline itself does stimulate the production of dopamine, so there is still some of the same positive feelings that nicotine would produce.
So, in effect, you can get the boost you need similar to what you would get from a cigarette without having to smoke a cigarette, or taking a nicotine substitute for that matter.
In essence, the chains of dependence are broken.
But that is not all you would have to do to be successful with this new medication. You also need to learn to break the other bad habits that reinforce your dependence. You need to avoid places you associate with smoking (such as bars and restaurants), or at least have to learn how to deal with those stimuli and challenges.
Programs such as the American Cancer Society’s Quitline ™ are designed to help you with your efforts, and Pfizer has announced they too will provide a support program.
How successful will varenicline be?
We really don’t know the answer to that as I write this.
According to information I have been provided, this drug was tested in relatively healthy smokers (if there is such a thing) who had no cardiac disease or problems with depression. The smokers in the clinical trial spanned a reasonable age range similar to typical smokers.
According to a Pfizer news release, 20% of smokers who used the medicine remained smoke free for over a year. The drug was four times as effective as a placebo, or dummy pill, and it was twice as effective as bupropion.
That may not sound like much, but it is fair to say that many of these folks had made multiple attempts to quit (we need to remember that, like any difficult habits, stopping smoking can take many, many attempts until you are successful. Pfizer says it takes on average 10 quit attempts before a smoker is successful in stopping).
We also need to remember that smoking is an addiction, and a chronic disease. So it is one that will be with a smoker for a lifetime, and the cravings don’t quit even many years after stopping.
So if we have a population of folks in this country who are hard core smokers (22% of our population, or 45 million Americans smoke) and we are able to keep 20% of them off of cigarettes for a year, then that is probably a considerable success under those conditions.
And, if the first effort isn’t effective, and they keep trying, eventually the odds are they are going to be successful. Over half the people in the United States who ever smoked and are alive today are former smokers.
What about side effects?
The official Food and Drug Administration announcement says the most common side effects are nausea, headache, vomiting, flatulence (gas), insomnia, abnormal dreams and a change in taste.
The frequency of nausea is not insignificant, and affected a majority of the participants in the clinical trial for a number of days after they started the medicine. That said, if the participants continued the medication, the nausea did resolve.
The bottom line is that the news of varenicline’s approval today is exciting. How quickly this medication is going to work its way into clinical practice is uncertain at this time.
We need to make a much better effort as doctors and clinicians to remind our patients about the dangers of smoking, and encourage them to quit. We need to provide and take advantage of the resources and medications available to smokers to help them stop smoking. We need to create environments (such as through clean air laws) where smoking is prohibited.
This new approach to smoking cessation is probably going to fairly quickly become part of our treatment programs if we are able to get folks into their doctors’ offices and have the doctors work with them by prescribing the medication and getting their patients into support programs.
But there are some cautions in my opinion that we also need to be aware of.
Recall that I mentioned above that the smokers in the clinical trials were relatively healthy. That makes them a select population of folks who smoke.
When we get into the real world with any new medication we have large numbers of people taking it who are not subject to the careful monitoring that occurs in a clinical trial.
That means that people with lung disease, heart disease, diabetes, hypertension and depression to name but a few conditions are going to be taking this medicine. That also means they will be taking a number of other medications at the same time.
Although it is obvious that the experts who developed the drug are knowledgeable about these considerations and have taken this into consideration, I always am a bit cautious about any new medicine and its potential other unanticipated side effects that may be found as the medicine becomes part of standard clinical practice.
If you are a “healthy” smoker similar to those studied in the clinical trial, you have a reasonably good idea of what to expect from varenicline. If you have many other serious medical conditions and take a number of other medications you need to be aware of any additional symptoms you develop if you start the medicine.
This advice is no different than I provided my patients when I was in practice, and is not unique to this medicine.
Many medicines have come to market and been extremely effective. But I have learned from experience that we do not learn everything we need to know about a drug like this from a clinical trial. The consequence is that “post marketing surveillance” is very important.
(By the way, as a piece of general information, if you have any unusual side effect from any prescription medication, you or your health care clinician can report it directly to the FDA on their website at MedWatch.
My sincere hope is that this medication is effective in helping those who are chronically addicted and possessed by their smoking habit. We need new advances like this to help these folks achieve the goal that many of them desire.
Time will tell if it is as effective as the studies suggest.
In the meantime, call us at 1-800-ACS-2345 24/7 and talk to us if you are ready to make the attempt, even if you have not been successful 10 times before.
