Studies show no extra risk with Pfizer smoking drug
Smokers who take Pfizer’s pill Chantix to help them quit do not have a higher risk of being hospitalized for psychiatric events such as depression, compared with nicotine patches, according to studies reported on Monday.
Users of Pfizer’s non-nicotine pill have reported agitation, depression and suicidal thoughts, and, in clinical trials, the pill was linked to nightmares.
Psychiatric symptoms have occurred in people without a history of mental illness and have worsened in people who already had mental illness, the FDA has said.
Although investors initially had high hopes for the drug, called Champix in Europe, reports of psychiatric effects have hampered sales growth.
The Food and Drug Administration released its review of two studies which compared Chantix to standard nicotine replacement therapy such as the Nicoderm nicotine patch from GlaxoSmithKline.
CHANTIX is a non-nicotine prescription medicine specifically developed to help adults 18 and over quit smoking. Over 7 million people in the U.S. have already been prescribed CHANTIX.
How is CHANTIX different from other smoking cessation products?
CHANTIX does not contain nicotine. It works in two ways. It targets nicotine receptors in the brain, attaches to them, and blocks nicotine from reaching them. It is believed that CHANTIX also activates these receptors, causing a reduced release of dopamine compared to nicotine.
It’s recommended that you begin your CHANTIX treatment a week before you stop smoking completely. This gives CHANTIX a chance to build up in your body. You may smoke during the first week of your CHANTIX treatment, but you should stop smoking completely on Day 8 of your treatment.
However, the FDA said the studies had limitations, and it would keep a restrictive “black box” warning on the smoking-cessation aid, advising about psychiatric side effects.
The drug has also been linked to a small increase in heart risk for those who already have heart problems, the FDA said in June.
“Overall, FDA has determined that the current warnings in the Chantix drug label, based on postmarketing surveillance reports, remain appropriate,” the agency said in a statement.
Chantix Side Effects
As with most prescription and non-prescription medication, Chantix may cause side effects.
Chantix patients have reported a variety of side effects including nausea, headache, sleep difficulties (insomnia, vivid or strange dreams), constipation and gas. If these symptoms persist or if they bother you, let you doctor know.
Other more serious side effects such as suicidal thoughts, depression and behavioral changes have been reported as well. It’s important to report these symptoms to your doctor. Your family or others around you may notice these effects before you notice them yourself.
Before taking Chantix, tell your doctor about any history of depression or other mental health problems, since these may worsen when taking Chantix.
Use caution while driving or operating machinery until you know how Chantix may affect you.
Chantix should not be taken with other quit smoking medications.
If you have a kidney disorder or receive dialysis, you may need a lower dose of Chantix.
If you are pregnant, plan to become pregnant, or if you take insulin, asthma medicines, or blood thinners, tell your doctor before you start taking Chantix.
Annual sales are now about $800 million, making the pill a moderate-sized product for the world’s biggest drugmaker.
The FDA said about 9.8 million people got Chantix prescriptions from U.S. retail pharmacies from the time the drug was approved in May 2006 through July of this year.
In one of the studies reported on Monday, the Department of Veterans Affairs compared 14,131 veterans using Chantix with an equal number of those using nicotine patches to see which group was hospitalized more frequently for psychiatric treatment during one year.
In the second study, the Department of Defense compared almost 20,000 Chantix users to about 16,000 people using nicotine patches for 30 days after each began treatment to stop smoking.
The FDA said the sample sizes in both studies were too small to analyze rare events. They also did not count psychiatric events that did not lead to hospitalization.
Pfizer is currently conducting its own large-scale trial to look at the risks of psychiatric events with Chantix, with results expected in 2017, the FDA said.
The company’s shares were up 0.5 percent to $19.15 on the New York Stock Exchange, versus a 0.2 percent rise in the S&P Pharmaceuticals Sub-Industry Index.
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(Reuters)