Quit Smoking Drug Safety Notice - Health Canada Update

Health Canada says it is in the process of strengthening safety information on the labels of the smoking-cessation product Champix.

In a statement Tuesday, it said it's working with the drugmaker Pfizer to update prescribing information after reports of serious psychiatric symptoms associated with the use of Champix.

Health Canada says label changes that increase awareness of the risk will be passed along to consumers and medical professionals when they are finalized.

Champix can be an effective tool for quitting smoking, it says, but there have been reports in some patients of unusual feelings of agitation, depressed mood, hostility, changes in behaviour, or impulsive or disturbing thoughts such as thoughts of self-harm or harm to others.

Health Canada says people taking the drug and their families are reminded to be aware of any unusual thoughts, feelings or behaviours, especially those related to depression, aggression or self-harm.

It isn't clear whether Champix is the cause of these psychiatric symptoms, but patients should stop the drug immediately if there are such concerns.

And patients should avoid driving or operating machinery until they're sure that Champix doesn't have an adverse effect on them, Health Canada said.

In issuing its reminder Tuesday, the federal agency noted that it's a time of year when many smokers are attempting to kick the habit.

In Montreal, Pfizer spokesman Christian Marcoux said that Champix is "safe and very efficacious" and that some symptoms are actually caused by the act of quitting smoking.

"Any individual attempting to quit smoking should be monitored and work with their physician because smoking cessation will generate or exacerbate such symptoms, with or without medication," he said.

He said the simple fact of quitting smoking will trigger behavioural changes.

"Smoking is a very nasty addiction and it's quite a challenge to work on that addiction," he said.
Source: CBC.ca, Health Canada

New Drug Prevents Addiction to Smoking/Alchohol

Can exercise help prevent addiction to drugs or alcohol?

Sure, exercise is good for your waistline, your heart, your bones - but might it also help prevent addiction to drugs or alcohol?

There are some tantalizing clues that physical activity might spur changes in the brain to do just that. Now the U.S. government is beginning a push for hard research to prove it.

This is not about getting average people to achieve the so-called runner's high, a feat of pretty intense athletics.

Instead, the question is just how regular physical activity of varying intensity - dancing, bicycling, swimming, tae kwan do - might affect mood, academic performance, even the very reward systems in the brain that can get hijacked by substance abuse.

What first caught the attention of National Institute on Drug Abuse chief Dr. Nora Volkow: A study found tweens and teens who reported exercising daily were half as likely to smoke as their sedentary counterparts, and 40 per cent less likely to experiment with marijuana.

Volkow knows - from her own almost 10-kilometre daily runs and from her scientific experiments - that the brain literally likes physical activity. Exercise seems to invigorate neurochemicals that sense and reinforce pleasure

"In children, it's innate," she notes. "Children want to move."

But the nation's children are becoming more sedentary, as illustrated by the obesity epidemic, "screen time" replacing outdoor play and a drop in school phys-ed. And as youngsters approach adolescence, the run around the yard that used to be fun too often becomes a chore - the dreaded jog around the school track or the nagging to get off the couch. The sedentary teen turns into the sedentary adult.

"Why do we lose the ability to experience pleasure from physical activity?" asks Volkow.

Last week she brought more than 100 specialists in exercise and neurobiology to a two-day conference to explore physical activity's potential in fighting substance abuse, and announced $4 million in new research grants to help.

Drug treatment programs often include exercise, partly to keep people distracted from their cravings, but there's been little formal research on the effects.

The best evidence: Brown University took smokers to the gym three times a week and found adding the exercise to a smoking-cessation program doubled women's chances of successfully kicking the habit. The quitters who worked out got an extra benefit: They gained half as much weight as women who managed to quit without exercising, says lead researcher Dr. Bess Marcus.

She now is working with the YMCA on a larger, NIDA-funded study to prove the benefit.

Marcus cautions that people trying to kick an addiction have a powerful incentive to exercise. Could that possibly translate into prevention? Among the clues:

-Rats were less likely to ingest amphetamines if their cages had running wheels, suggesting exercise stimulated a reward pathway in the brain to leave them less vulnerable to the drug's rush.

-In people, exercise acts as a mild antidepressant and relieves stress. Depression, anxiety and stress increase risk of alcoholism, smoking or drug abuse.

-Volkow is intrigued that attention deficit disorder and obesity both involve problems with the brain chemical dopamine, one system that drugs hijack to create addiction.

-Baby monkeys who don't play enough in childhood have problems controlling aggression when they're older. The most aggressive tend to have defects involving the feel-good brain chemical serotonin - and binge-drink when researchers offer them alcohol.

-Back to rats, physical activity increases production of growth factors and stem cells in key brain regions important for learning and mood; increases formation of blood vessels; and strengthens communication networks between brain cells.

Together, that's far too little research to know if exercise really matters for substance abuse, scientists at the National Institutes of Health meeting cautioned.

But, a few studies of school-age children suggest physical activity predicts better performance on math, verbal and other tests - and better school performance in turn is linked to lower risk for substance abuse.

And getting sedentary seniors moving improves brain function - research aimed at preventing dementia, not drug abuse, although the improvement is in an area that in younger people is linked to risky decision-making.

A caveat: If your own youth includes memories of parties with beer-guzzling athletes, well, the research concurs. A major study that tracks adolescent risk behaviours found that by 12th grade, exercise offers no protection against binge-drinking.

"Now the kids who exercise the most actually drink the most," says Dr. Lloyd Johnston of the University of Michigan. It may have to do with the celebratory nature of team sports, or getting revved for college - or, other researchers suggested, even that competition is to blame.

Source: CBC.ca

New Stop Smoking Drug Approval

Stop-smoking drug wins Health Canada approval

Champix boasts 22 per cent success rate, has no nicotine base

Last Updated: Thursday, January 25, 2007 | 3:54 PM ET

Health Canada has given the nod to the first smoking-cessation drug to hit the market in a decade.

Champix — which was discovered and developed by Pfizer — is one of two quit-smoking drugs that are not designed to replace the nicotine kick that cigarettes offer.

The drug works in two ways — by cutting the pleasure of smoking and reducing the withdrawal symptoms that frequently derail smokers' efforts to quit. If a person smokes while taking Champix, the drug can reduce the sense of satisfaction associated with smoking.

Champix latches on to the same receptors in the brain that nicotine binds to when inhaled in cigarette smoke. The action leads to the release of dopamine in the pleasure centres of the brain. Taking the drug blocks any inhaled nicotine from reinforcing that effect.

Most other stop-smoking drugs are nicotine-replacement therapies, either sold by prescription or over the counter in gum, patch, lozenge, nasal spray or inhaler form. The only other prescription drug sold to help people to quit smoking is Zyban. In the United States, Champix sold under the brand name Chantix.

Champix was approved for sale in Europe in 2006.

Several studies conducted in Europe on about 2,000 smokers showed that a year after initial treatment with Champix, a little more than one in five people stayed off cigarettes. Zyban's success rate is estimated at about 16 per cent. Only eight per cent of those who were given a placebo in the study had stopped smoking after a year.

Champix treatment includes 12 weeks of taking the drug as well as smoking-cessation counselling. Pfizer said the drug's possible side-effects include nausea, abnormal dreams, constipation, flatulence and vomiting.

According to Health Canada, more than 4.5 million Canadians — or about 18 per cent of the population age 15 years and older — smoke. More than 37,000 people die prematurely each year in Canada due to tobacco use and at least 800 non-smokers die every year from exposure to second-hand smoke.

Source: CBC.ca Jan. 25/07