Pfizer anti-smoking drug under FDA safety review

Pfizer anti-smoking drug under FDA safety review
An ink-stained finger is seen holding on to a cigarette in Amman, Iraq December 14, 2005. The U.S. Food and Drug Administration issued an early warning on Tuesday about Pfizer Inc's anti-smoking drug, Chantix, amid reports of suicidal thoughts and behavior, and at least one death potentially linked to the medication. (Ali Jarekji/Reuters)WASHINGTON (Reuters) - The U.S. Food and DrugAdministration issued an early warning on Tuesday about PfizerInc's anti-smoking drug, Chantix, amid reports of suicidalthoughts and behavior, and at least one death potentiallylinked to the medication.
The FDA is analyzing reports of erratic and aggressivebehavior and suicidal thoughts and behavior in patients takingthe prescription drug, known generically as varenicline.
An early agency assessment "reveals that many of the casesreflect new-onset of depressed mood, suicidal ideation(thoughts) and changes in emotion and behavior within days toweeks" of starting treatment, the FDA said in a posting aboutthe new review.
Under increased scrutiny from lawmakers and consumer groupsfor failing to communicate safety problems with drugs in atimely manner, the FDA has started alerting the public earlierabout a review, even if it has not come to a conclusion.
Many drugmakers claim the agency is taking a tougher stanceon safety following the 2004 withdrawal of Merck & Co Inc'sarthritis drug, Vioxx, and amid recent safety concerns aboutGlaxoSmithKline Plc's diabetes drug, Avandia.
"My first thought is this is another example of the FDAbeing overly safety conscious in light of the withdrawal ofcertain products, such as Vioxx and Avandia," said DamienConover, an analyst at investment research group Morningstar.
But he said it could still be a problem for Chantix.
"When the (attention deficit disorder) drugs got associatedwith increased risk of suicidal thinking, you definitely saw aclass effect of slower growth," he added.
Pfizer, the world's biggest pharmaceutical company,reported revenue of $241 million for Chantix in the thirdquarter of 2007. That is significant, but still not one of itsmajor drugs. It recently launched an ad campaign touting thedrug, which it began selling last year.
CAUSALITY UP IN AIR
The FDA stressed the warning "does not mean that FDA hasconcluded that there is a causal relationship between the drugand the emerging safety issue."
Adverse event reports following a drug's approval arevoluntarily submitted to companies by consumers and doctors andare a very rough indicator of any potential trends, a Pfizerofficial said.
"Postmarketing reports usually do not allow you toestablish a causality because there is very often a significantamount of information missing," said Martina Flammer, a seniormedical director at Pfizer.
She also noted that programs to stop smoking very oftenlead to nicotine withdrawal, which is exacerbated in patientswith psychiatric illness.
The FDA noted, however, that not all patients in the casesnoted had a preexisting psychiatric illness and not all hadstopped smoking.
In its alert, the FDA cited one case of a patient whoseerratic behavior while on the drug lead to death, but addedthat alcohol was also involved.
Doctors are advised to monitor patients taking the drug forchanges in behavior and mood, the FDA said.
Pfizer shares closed up 1 cent at $22.72 on the New YorkStock Exchange.(Reporting by Kim Dixon; additional reporting by ToniClarke and Lewis Krauskopf; editing by Jeffrey Benkoe and AndreGrenon)