		Thomas S. May, M.A. Medical Writer
Home Portfolio Contact		Psoriasis Medication may Help Smokers Quit Thomas S. May, Medical Writer A medication currently used to treat severe cases of psoriasis (a disorder marked by patches of red, flaky skin) may help smokers kick the habit, according to researchers at the University of Toronto, Ontario, Canada. The scientists discovered that the drug methoxsalen has an interesting side effect: It slows down the metabolism of nicotine in the body. Heavy smokers are addicted to nicotine, and they usually try to maintain their blood nicotine levels by smoking cigarettes (or some other tobacco products) at more or less regular intervals. When the concentration of nicotine in their blood drops, smokers light up again, in order to increase the concentration and reduce the craving. Methoxsalen can lower the craving by making nicotine stay in the blood longer, the researchers say. As a result, smokers taking the drug automatically cut down on the number of cigarettes smoked, making it much easier for them to quit eventually. "It's easier to jump off a curb than it is out of a first floor window. People can stop more easily if their patterns of smoking are much lower," says Edward Sellers, MD, PhD, a professor of pharmacology and lead author of the study. A Very, Very Large Effect In one of the experiments conducted by Dr. Sellers and his colleagues, smokers were given either methoxsalen or placebo in combination with nicotine or placebo. After a 60-minute period of abstinence, the subjects were allowed to smoke at will for 90 minutes. Smokers who received methoxsalen plus nicotine smoked fewer cigarettes, had longer intervals between cigarettes, and took fewer puffs on each cigarette than those who were assigned to the other groups. "It was a very, very large effect," says Dr. Sellers, referring to the results. The investigators also measured the amount of carbon monoxide in the breath of all study participants at the end of the free smoking period. They found that methoxsalen plus nicotine given orally decreased breath carbon monoxide concentration by an average of 47%. More Nicotine, Less Poison? Giving smokers a combination of methoxsalen and nicotine temporarily increases the amount of nicotine in their blood, the researchers admit. But--aside from the fact that it is highly addictive--nicotine is not a very dangerous substance, the scientists say. "Toxic effects of nicotine aren't really observed in smokers," according to Rachel Tyndale, PhD, one of the co-authors of the study. "Nicotine has very low toxicity in smokers or ex-smokers, as they have a high tolerance for the effects of this drug," Dr. Tyndale explains. Also, because they cut down on the amount of smoke inhaled, smokers are exposed to much less of the hundreds of poisonous chemicals contained in cigarette smoke, the investigators argue. "Nicotine is really quite safe compared to all the nasty stuff in tobacco smoke." says Dr. Sellers. "So reducing your smoking or stopping, even if you still have some nicotine in your system, is a huge, huge advantage over smoking," he adds. Pop a Pill and Chuck the Butt Of course, the ultimate goal of most smokers is to be able to give up the habit completely. In the United States, for example, about 70% of smokers say they want to quit, but only 2.5% succeed per year, according to the most recent statistics from the Centers for Disease Control and Prevention (CDC). These low success rates could be increased significantly if smokers had access to a pill that would reduce their cravings for nicotine, Dr. Sellers believes. The main reason for this is that "most people prefer to take their medication in the form of a pill," he says. Nicotine replacement therapy (NRT) is a method of smoking cessation that aims to reduce the craving for nicotine experienced by smokers. NRT is currently available in the form of a gum, nasal spray, inhaler, or skin patch. At present, there is no oral form of NRT, because, if taken by mouth, nicotine is quickly metabolized in the liver and not enough of it gets into the bloodstream to reduce the craving. However, if nicotine could be combined with a drug like methoxsalen, which inhibits its metabolism, oral replacements would be viable, according to Dr. Sellers. A combined nicotine-methoxsalen pill would have other benefits too, besides being more convenient than other, currently available forms of NRT, the researchers point out. For example, "it would allow accurate predictions of the blood levels of nicotine achieved, and, therefore, accurate dosing," says Dr. Tyndale. When will it be Available? Although the initial research results look promising, a "stop-smoking pill" is likely to be at least a couple of years away, according to Dr. Sellers. "We need to do longer-term studies to establish the efficacy and safety [of a combination nicotine-methoxsalen pill]," he says. Jack Henningfield, PhD, a renowned expert on nicotine addiction, agrees: "At this point, the science base tells little more than that methoxsalen merits further consideration and study for smoking cessation," he explains. Giving smokers extra nicotine, along with a drug that slows its metabolism, may involve some risks, Dr. Henningfield cautions. "We must bear in mind, however, that tobacco dependence is an extremely severe disorder with a premature mortality rate of 50% and enormous health gains for those who quit. So, if methoxsalen offers an effective and acceptable treatment for persons who find other treatments unacceptable or ineffective, the potential benefits may easily outweigh such risks," he says.

Thomas S. May, M.A.

Medical Writer

Psoriasis Medication may Help Smokers Quit

Thomas S. May, Medical Writer

A medication currently used to treat severe cases of psoriasis (a disorder marked by patches of red, flaky skin) may help smokers kick the habit, according to researchers at the University of Toronto, Ontario, Canada. The scientists discovered that the drug methoxsalen has an interesting side effect: It slows down the metabolism of nicotine in the body.

Heavy smokers are addicted to nicotine, and they usually try to maintain their blood nicotine levels by smoking cigarettes (or some other tobacco products) at more or less regular intervals. When the concentration of nicotine in their blood drops, smokers light up again, in order to increase the concentration and reduce the craving.

Methoxsalen can lower the craving by making nicotine stay in the blood longer, the researchers say. As a result, smokers taking the drug automatically cut down on the number of cigarettes smoked, making it much easier for them to quit eventually.

"It's easier to jump off a curb than it is out of a first floor window. People can stop more easily if their patterns of smoking are much lower," says Edward Sellers, MD, PhD, a professor of pharmacology and lead author of the study.

A Very, Very Large Effect

In one of the experiments conducted by Dr. Sellers and his colleagues, smokers were given either methoxsalen or placebo in combination with nicotine or placebo. After a 60-minute period of abstinence, the subjects were allowed to smoke at will for 90 minutes.

Smokers who received methoxsalen plus nicotine smoked fewer cigarettes, had longer intervals between cigarettes, and took fewer puffs on each cigarette than those who were assigned to the other groups. "It was a very, very large effect," says Dr. Sellers, referring to the results.

The investigators also measured the amount of carbon monoxide in the breath of all study participants at the end of the free smoking period. They found that methoxsalen plus nicotine given orally decreased breath carbon monoxide concentration by an average of 47%.

More Nicotine, Less Poison?

Giving smokers a combination of methoxsalen and nicotine temporarily increases the amount of nicotine in their blood, the researchers admit. But--aside from the fact that it is highly addictive--nicotine is not a very dangerous substance, the scientists say.

"Toxic effects of nicotine aren't really observed in smokers," according to Rachel Tyndale, PhD, one of the co-authors of the study. "Nicotine has very low toxicity in smokers or ex-smokers, as they have a high tolerance for the effects of this drug," Dr. Tyndale explains.

Also, because they cut down on the amount of smoke inhaled, smokers are exposed to much less of the hundreds of poisonous chemicals contained in cigarette smoke, the investigators argue.

"Nicotine is really quite safe compared to all the nasty stuff in tobacco smoke." says Dr. Sellers. "So reducing your smoking or stopping, even if you still have some nicotine in your system, is a huge, huge advantage over smoking," he adds.

Pop a Pill and Chuck the Butt

Of course, the ultimate goal of most smokers is to be able to give up the habit completely. In the United States, for example, about 70% of smokers say they want to quit, but only 2.5% succeed per year, according to the most recent statistics from the Centers for Disease Control and Prevention (CDC).

These low success rates could be increased significantly if smokers had access to a pill that would reduce their cravings for nicotine, Dr. Sellers believes. The main reason for this is that "most people prefer to take their medication in the form of a pill," he says.

Nicotine replacement therapy (NRT) is a method of smoking cessation that aims to reduce the craving for nicotine experienced by smokers. NRT is currently available in the form of a gum, nasal spray, inhaler, or skin patch.

At present, there is no oral form of NRT, because, if taken by mouth, nicotine is quickly metabolized in the liver and not enough of it gets into the bloodstream to reduce the craving. However, if nicotine could be combined with a drug like methoxsalen, which inhibits its metabolism, oral replacements would be viable, according to Dr. Sellers.

A combined nicotine-methoxsalen pill would have other benefits too, besides being more convenient than other, currently available forms of NRT, the researchers point out. For example, "it would allow accurate predictions of the blood levels of nicotine achieved, and, therefore, accurate dosing," says Dr. Tyndale.

When will it be Available?

Although the initial research results look promising, a "stop-smoking pill" is likely to be at least a couple of years away, according to Dr. Sellers. "We need to do longer-term studies to establish the efficacy and safety [of a combination nicotine-methoxsalen pill]," he says.

Jack Henningfield, PhD, a renowned expert on nicotine addiction, agrees: "At this point, the science base tells little more than that methoxsalen merits further consideration and study for smoking cessation," he explains.

Giving smokers extra nicotine, along with a drug that slows its metabolism, may involve some risks, Dr. Henningfield cautions. "We must bear in mind, however, that tobacco dependence is an extremely severe disorder with a premature mortality rate of 50% and enormous health gains for those who quit. So, if methoxsalen offers an effective and acceptable treatment for persons who find other treatments unacceptable or ineffective, the potential benefits may easily outweigh such risks," he says.