With smoking cessation drugs, dosing is key

When it comes to smoking cessation, the statistics can be disheartening. Nearly a quarter of all US adults smoke, and nearly two-thirds of them want to quit. But while about half try to kick the habit each year, only about seven percent who try to stop on their own do so for good. Just as depressing, those who eventually quit typically try between five and seven times. What you may not know, however, is how cigarettes deliver nicotine and how you can best prescribe commonly available drug therapies to mimic that delivery system. Over the years, experts have learned some valuable lessons about how to make the most of drug therapies for smoking cessation. While counseling and behavioral therapy are important strategies to help patients stop smoking, many experts say nearly all of them will need help in the form of drug therapy. By using the right drug doses and combining therapies, they say, you can take some concrete steps to help patients quit for good.

The right dose • The FDA has approved five first-line drug therapies to treat tobacco dependence. Four involve nicotine replacement, including transdermal patches, gum, vapor inhalers and nasal sprays. The fifth, sustained-release bupropion, is a monocyclic antidepressant. Nicotine patches are now available as an over-the-counter (OTC) drug only. Nicotine nasal sprays and inhalers are prescription-only; gum is OTC-only. According to US Public Health Service guidelines, nicotine gum improves long-term abstinence rates by approximately 30 percent to 80 percent over placebo. The patch improves those rates between 70 percent and 120 percent. Far fewer studies of the inhaler and nasal spray have been done, but meta-analyses of studies on both products indicate they offer double the cessation rates of placebo. Thre are no hard-and-fast rules about which medication will work best for individual patients. The key, however, is to make sure your patient gets enough nicotine. Underdosing is not uncommon explained by the director of the Mayo Clinic Nicotine Dependence Center in Rochester, Minn. Studies have found that a standard dose of patch therapy results in a cotinine level – the nicotine metabolite – of only about half what the patient would get through smoking. Heavy smokers in particular need more treatment.

If your patients use a patch, for example, one doctor recommended asking how many cigarettes they smoke each day to establish the right level of nicotine replacement. He gave these guidelines, which he uses in his practice:

• Patients who smoke fewer than 10 cigarettes per day need a patch dose of 7 mg to 14 mg per day.

• Patients who smoke between 10 and 20 cigarettes a day need a dose of 14 mg to 22 mg per day.

• Patients who smoke between 21 and 40 cigarettes daily need a patch dose of 22 mg to 44 mg daily.

• Heavy smokers-people who smoke more than 40 cigarettes a day-need at least 44 mg per day from the patch.

Another key to successful smoking cessation strategies is giving patients detailed instructions. I would not encourage gum usage unless you spend a few minutes explaining how to use it. Tell patients not to chew the gum, but rather take a few bites until the gum’s distinct taste indicates nicotine is being released. At that point, patients should hold the gum between their teeth and gum so the nicotine can be absorbed through the oral mucosa. And if the patients are using gum only, give them a schedule that specifies when they should use it. You need to put them on a regimen, (Guidelines form the US Public Health Service recommend one piece per hour, up to 24 pieces per day).

Dual therapies • Another issue to watch out for: Cravings. If your patient has tried to quit before-and many have-and couldn’t overcome cravings, you should consider using more than one therapy. The nicotine patch is the base product, but if the patient experiences breakthrough withdrawal cravings, you might want to pair it with gum, inhaler or nasal spray. This dual therapy will give a steady background nicotine level and allow patients to increase their nicotine intake when they experience cravings. Dual therapies illustrate one of the great challenges of smoking cessation. While nicotine replacement therapies deliver nicotine in different ways, none are as efficient as smoking. Cigarettes, after all, pump nicotine into the bloodstream quickly and give smokers easy access to the drug any time they wish. Nicotine enters the bloodstream within five to seven heartbeats after a puff on a cigarette. With the patch, on the other hand, blood nicotine levels peak within two to four hours and stay constant for 16 to 24 hours, depending on the dosage. Other smoking cessation drugs peak much sooner and don’t last as long. Nasal sprays, for example, work within five to 10 minutes, and both the gum and inhaler work within 20 minutes.

Duration • Duration is another critical consideration of smoking cessation treatments, that under physician guidance, most patients use the patch for four to eight weeks. (The FDA has approved the patch for a maximum of eight weeks.) However, explained that it is safe to use the patch longer if necessary. Smokers trying to quit on their own tend to use the patch for even less time, making it far less effective. One doctor from Group Health, for example, said that most people who purchase patches over-the-counter on their own use them an average of one to two weeks. FDA approved timeframes for taking the other drugs range from seven to 12 weeks for bupropion and three to six months for nicotine vapor inhalers and nasal sprays.

Contraindications and side effects • In a few circumstances, smoking cessation medications may be contraindicated. Pregnant smokers, for example, should first try to quit without medications. However, said that if a pregnant smoker does not succeed in quitting with a behavioral program, it is safer to have her use nicotine replacement drugs than to continue smoking. It was noted that many obstetrician prescribe nicotine replacement therapies in this situation. In addition, the safety of nicotine replacement therapies has not been established in patients who have had myocardial infarction in the past two weeks and in patients with severe or unstable angina. US Public Health Service guidelines say that you can use the products with these patients, but you should prescribe with caution. The safety of nicotine patches in patients, who have stable angina or have had a heart attack more than two weeks ago has been demonstrated in randomized studies. Physicians should not hesitate to use the patch in these patients. Remember that nicotine replacement can create problems for some patients. The patch, for example, can cause skin irritation and "insomnia or excessively vivid, disturbing dreams, and nasal sprays can also cause nasal irritation. Some patients have also reported difficulty tapering their use of nasal sprays because their mechanism of delivering nicotine to the brain is so similar to cigarettes.

Experts suggest that you talk about nicotine withdrawal symptoms, possible side effects and the appropriate use of drugs before starting treatment to prepare patients and bead off some problems. Removing the patch before going to bed, for example, may help prevent disturbing dreams.

Bupropion • If your patient wants to quit smoking and has a history of depression or is currently battling the disease, bupropion may be a good choice because it doubles as an antidepressant. What if your patient is already taking an antidepressant? Experts say that under certain circumstances, you can give bupropion to patients who are already taking low doses of selective serotinin reuptake inhibitors (SSRI) like fluoxetine or paroxetine, that if you combine the two therapies, however, you should consider having the patient take 150 mg of bupropion once a day. Bupropion studies suggest that long-term cessation rates are equivalent at one year for 150 mg and 300 mg. Added that it’s probably not a good idea to switch a patient to bupropion from an SSRI solely for the purpose of smoking cessation. They have done it, but only with patients who were not happy with the SSRI anyway. Added that he would be cautious about making the switch because smoking cessation increases the likelihood of depression relapse. Switching from an antidepressant that is working well for an individual to an untried one solely to help the patient stop smoking may have unpredictable results. Bupropion can also be a good choice for patients who don’t want to wear a patch. Family physician, of Grand Junction, Colorado, said he regularly favors bupropion over nicotine patch therapy. He’s not a great advocate of patches. He thinks the psychological addiction of nicotine is greater than the physical aspect.

Bupropion is not recommended for people with histories of seizures, serious head traumas with a loss of consciousness or eating disorders, or for patients taking other medications that lower the seizure threshold. It should be started seven days before a patient’s scheduled quit date in order to have adequate levels in the system. While experts sa that bupropion can produce fairly mild side effects like insomnia and dry mouth, the symptoms can be enough to cause some patients to stop therapy. There are two ways to get around this problem. First, you can have the patient take the second dose earlier in the day, at around 5:00 pm. instead of 8:00 pm. Second, you can suggest patients take the drug once a day instead of twice a day and cut back to a single, 150-mg dose. As with other smoking cessation therapies, pairing bupropion with the patch may be a good choice for patients who have unsuccessfully tried to quit many times or smoke heavily.

Patient preferences • Some final tips: In many cases, absent any contraindications, the decision about which drug to use comes down to patient preference, past experience with the products and insurance coverage. They try to find out about patients’ previous experiences trying to quit. The vast majority have made prior attempts, and if they had success with a certain agent, but had a late relapse, then retry them on that agent. And don’t automatically accept at face value patient’s statements that previous products didn’t work. You need to delve a little deeper to understand why they think they didn’t work. The patient might say the therapy didn’t work, but what really happened is that he had a relapse after six months. Finally, while drug therapy will give your patients a critical edge in kicking the habit, studies show that the best way to make sure they quit for good is to provide education and support. Suggested scheduling check-back visits with physicians or nurses, calling patients to check on their progress, or referring them to smoking-cessation resources in the community.