Doubts About The Drug From Pfizer For Smoking Cessation
Chantix, the first drug designed to combat smoking, is under the shadow of a doubt. A group of scientists from Johns Hopkins, U.S., yesterday published a study linking varenicline (Chantix the active ingredient) with an increase in heart attacks. Pfizer, the laboratory of the seller, said that the survey data are statistically irrelevant, but the drug's safety review by the agency of the U.S. drug, the FDA.
A drug for smoking cessation was for years one of the objectives of the pharmaceutical industry, millions of smokers in the world would be potential buyers. The nicotine patches and gum simply mimic the action of smoking on the body and labs aimed to improve the response to the pharmacology.
This brings me Chantix, approved in the EU in 2006 and is marketed in Spain since January 2007. Varenicline is a molecule that binds to neuronal nicotine use (so-called-4 receptor alpha, beta-2). There are two effects. On the one hand blocks the absorption of nicotine. On the other caused a slight release of dopamine, the same neurotransmitter that is secreted by smoking.
Worldwide, sales amounted to EUR 550 million (a modest figure on Pfizer), according to Reuters. The laboratory reported that in the first six months of the year, roughly 65,000 people in Spain have started treatment (compared to 110,000 around 2010). The full cost of treatment is about 300 Euros.
The team led by Sonal Singh Professor of Medicine in September 2010 began a review of clinical trials with Chantix. Of these selected 14 studies with a number of features: the treatment compared with placebo, neither the doctor nor the patient knew what they were taking (double blind), and so on.
The result, published in the Journal of the Canadian Medical Association (CMAJ, its acronym in English), revealed an increase in cardiovascular problems in the group that had taken varenicline. The review found that in 4908 smokers who received the drug were 52 cases (1.06%) of angina, ischemia, infarction or sudden death. Among the 3308 placebo, there were 27 cases (0.82%).
The report concludes that the findings "raise questions about the safety" of drug "because of the potential increased risk of serious cardiovascular events associated with the use of varenicline in smokers."
But everything is interpretable statistics. The difference between 0.82% and 1.06% for the authors is an increased risk of 72% attributable to Chantix. But for Jos Chaves, chief medical officer of Primary Pfizer Spain is "just a quarter point and very small numbers. With less than 500 adverse events is unreliable. Chaves notes that the European Medicines Agency has now revised the drug's safety-compulsory age of five in the market, "without finding anything." The lab also believes that there is bias in the study that tips the balance against its presentation.
If Chantix falls, not the first time that a multinational is one of his bestselling apart by a separate analysis (not even the official agencies of the drug). In September 2010, recalled Europe Avandia, a diabetes drug from GlaxoSmithKline. Steven E. Nissen, a cardiologist at the Cleveland Clinic, published in 2007 that the generic drug cardiovascular problems. The controversy in the medical community took more than three years, but governments proved him right.
A drug for smoking cessation was for years one of the objectives of the pharmaceutical industry, millions of smokers in the world would be potential buyers. The nicotine patches and gum simply mimic the action of smoking on the body and labs aimed to improve the response to the pharmacology.
This brings me Chantix, approved in the EU in 2006 and is marketed in Spain since January 2007. Varenicline is a molecule that binds to neuronal nicotine use (so-called-4 receptor alpha, beta-2). There are two effects. On the one hand blocks the absorption of nicotine. On the other caused a slight release of dopamine, the same neurotransmitter that is secreted by smoking.
Worldwide, sales amounted to EUR 550 million (a modest figure on Pfizer), according to Reuters. The laboratory reported that in the first six months of the year, roughly 65,000 people in Spain have started treatment (compared to 110,000 around 2010). The full cost of treatment is about 300 Euros.
The team led by Sonal Singh Professor of Medicine in September 2010 began a review of clinical trials with Chantix. Of these selected 14 studies with a number of features: the treatment compared with placebo, neither the doctor nor the patient knew what they were taking (double blind), and so on.
The result, published in the Journal of the Canadian Medical Association (CMAJ, its acronym in English), revealed an increase in cardiovascular problems in the group that had taken varenicline. The review found that in 4908 smokers who received the drug were 52 cases (1.06%) of angina, ischemia, infarction or sudden death. Among the 3308 placebo, there were 27 cases (0.82%).
The report concludes that the findings "raise questions about the safety" of drug "because of the potential increased risk of serious cardiovascular events associated with the use of varenicline in smokers."
But everything is interpretable statistics. The difference between 0.82% and 1.06% for the authors is an increased risk of 72% attributable to Chantix. But for Jos Chaves, chief medical officer of Primary Pfizer Spain is "just a quarter point and very small numbers. With less than 500 adverse events is unreliable. Chaves notes that the European Medicines Agency has now revised the drug's safety-compulsory age of five in the market, "without finding anything." The lab also believes that there is bias in the study that tips the balance against its presentation.
If Chantix falls, not the first time that a multinational is one of his bestselling apart by a separate analysis (not even the official agencies of the drug). In September 2010, recalled Europe Avandia, a diabetes drug from GlaxoSmithKline. Steven E. Nissen, a cardiologist at the Cleveland Clinic, published in 2007 that the generic drug cardiovascular problems. The controversy in the medical community took more than three years, but governments proved him right.
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