Pharmaceutical giant Pfizer Inc. is blitzing the public and doctors in response to widespread reports and concerns about the safety of its stop-smoking drug, Chantix, Bloomberg reported May 28.

The company recently ran ads in the nation's five largest newspapers and sent letters to 300,000 healthcare professionals about Chantix, and also plans to hold special briefings for reporters. The moves come after the Institute for Safe Medication Practices reported that Chantix has been linked to suicide, seizures, and traffic crashes, a similar report from the FDA, and a federal ban on airline pilots and air-traffic controllers using the drug.

Sales of Chantix have fallen by about one-third since January, when the FDA report came out, and Pfizer's shares have fallen 30 percent in value in the last year.

"When there is confusion in the marketplace related to one of our products we want to make sure the right information is out there,'' said Pfizer spokesperson Ray Kerins. "We can't lose sight of the benefit of this product, the public-health benefit is clear."

The newspaper ads focus on the dangers of smoking and the benefits of Chantix, but also warn users to stop taking Chantix if their mood or behavior changes.