'Anti-smoking drugs may up heart attack risk'
Washington: People who take help of
anti-smoking drugs to kick the butt are 72 per cent more prone
to serious heart attacks than those who take sham medications,
a new study led by an Indian-origin scientist has claimed.
Researchers at Johns Hopkins Medical Institutions in
the US found that healthy and middle-aged smokers who take
varenicline, the widely-used smoking cessation drug on the
market, had a 72 per cent increased risk of being hospitalised
with a heart attack or other serious heart problems.
"People want to quit smoking to reduce the risk of
cardiovascular disease but in this case they`re taking a drug
that increases the risk for the very problems they`re trying
to avoid," said lead researcher Sonal Singh, an assistant
professor of internal medicine at Johns Hopkins.
In the study, published in the Canadian Medical
Association Journal, Singh and his colleagues analysed 14
double-blind, randomised, controlled clinical trials involving
more than 8,200 healthy people who received either varenicline
or a placebo. Varenicline made by Pfizer is sold in many
countries including India under the brand-name Chantix.
While the number of people who died in each group was
the same (seven), the researchers found that the risk of a
major harmful cardiovascular event requiring hospitalisation
such as a heart attack or arrhythmia was 72 per cent in the
None of the studies followed people for longer than a
year. The average age of study participants was less than 45
years and the majority were men.
Varenicline has been shown to increase the chances of
a successful quit attempt, compared to unassisted smoking
cessation attempts. But overall, the majority of smokers who
quit do so without any assistance at all.
Moreover, Singh noted, varenicline already carries a
boxed warning -- the Food and Drug Administration`s highest
level of caution -- because of its association with suicidal
thoughts and behaviours.
"We notified the FDA of our cardiovascular safety
concerns with Chantix earlier this year," Singh said.
On June 16, the FDA announced that on the basis of a
700-person study, people with existing heart disease who use
varenicline have a slightly increased risk of a heart attack
or other cardiovascular event.
But Singh`s study found that varenicline substantially
increased the risk of a serious cardiovascular event even
among smokers without heart disease.
"I think our new research shifts the risk-benefit
profile of varenicline. People should be concerned. They don`t
need Chantix to quit and this is another reason to consider
avoiding Chantix altogether," Singh said.
Smoking has long been associated with increased risk
of cardiovascular disease and cardiac death and quitting is
known to reduce those risks.
The researchers also emphasised the need to quit the
habit, but suggested that varenicline may not be the right
drug to kick the habit.