Consumers across the country have alleged in more than 400 lawsuits filed in courts and complaints logged with federal regulators that Zicam nasal gel, meant to relieve cold symptoms, has destroyed or diminished their sense of smell or taste.
Some consumers and experts say the controversy shows there hole in the government's oversight of homeopathic products such as Zicam.
Zicam's manufacturer, Phoenix-based Matrixx Initiatives, says its Zicam medicines are safe and that it has research to back it up.
Matrixx settled a batch of 340 lawsuits for $12 million in January 2006, court and SEC documents show. The company did not admit fault. Since then, Matrixx has fought off more lawsuits using a panel of medical experts and piles of scientific evidence.
Matrixx representatives say the controversy over Zicam boils down to one Colorado doctor, who first publicly linked Zicam to smell loss, and lawyers out to make a quick buck. Since September 2006, six federal courts have tossed out expert testimony from the doctor, Bruce Jafek, a University of Colorado School of Medicine ear, nose and throat specialist.
Companies that sell homeopathic products are not required to go through the same rigorous approval process and government-vetted clinical trials that pharmaceutical companies must complete before the Food and Drug Administration will allow them to make a prescription drug available for public consumption.
The FDA has received more than 200 complaints from consumers about Zicam gel, which is sold over-the-counter.
The agency, which must deal with urgent public health issues such as the contaminated toothpaste ingredients from China, recalls only few over-the-counter products. For example, it banned the nutritional supplement ephedra in 2004 after it was linked to increased blood pressure and irregular heart rhythm.
"I don't know of any immediate action on Zicam," said FDA spokeswoman Sandy Walsh.
David Richardson, a packaging equipment salesman in Greensboro, N.C, wants the FDA to require an independent study of the safety of Zicam gel, which uses a long, narrow nozzle to pump zinc gluconate into the nose.
Richardson first tried Zicam two years ago when he wanted quick relief from a cold. A few days later, he noticed that scents seemed distorted. Even strong odors, such as gasoline, had a metallic scent. He also said he lost his sense of taste as the two senses are linked.
"This has changed my whole life," Richardson said. "Heaven forbid some mother gives it to her 6-year-old kid."
Matrixx Initiatives did $96 million in sales last year, making most of its money from sales of Zicam-branded products, which include the nasal gel, swabs, a spray and pills.
The company woos consumers with its slogan, "Better ways to get better," and sells cold and cough, allergy, and sinus medications at chain retailers such as Wal-Mart, Walgreens and CVS. Matrixx also has touted its products in radio and television ads featuring talk-show personality Rush Limbaugh and customer testimonials.
But in 2003, Jafek reported in a medical conference on 10 cases of smell loss linked to use of zinc gluconate. Other doctors followed, including Terrence Davidson, director of the University of California-San Diego Nasal Dysfunction Clinic.
It had long been known that zinc could harm nasal tissue when administered in high enough doses. Jafek and others theorized that the force of the Zicam gel pump could deliver toxic doses of zinc and damage sensitive nose tissues. Some patients probably sniffed the zinc after applying the gel in their nose. That, in turn, triggered loss of smell.
After the lawsuits began trickling in, Matrixx commissioned its own panel of doctors and scientists. They reviewed existing scientific literature and concluded there is no evidence that a zinc-based nasal gel such as Zicam can lead to smell loss.
The company-hired experts conducted studies on the incidence of smell loss in the general population, the impact of a zinc gluconate gel on mice and whether the Zicam gel pump could reach sensitive smell tissue in cadavers. They concluded that the most likely cause of smell loss is the cold virus itself, sinus problems or nasal injury.
"The company is satisfied the product is safe," Matrixx spokesman Rob Murphy said.
Jafek said he remains concerned about the effect of zinc in the nose: "I have done the best I can to alert the scientific community of this problem so that we can prevent other patients from suffering avoidable loss of smell."