WASHINGTON, Jan 26, 2008 (AFP) - The advocacy group Public Citizen has petitioned US regulatory authorities to increase its warnings on Botox, the toxin used by millions around the world to temporarily erase wrinkles.

However neither Allergen Inc, the company that produces and sells Botox, nor the American Society for Dermatologic Surgery, which groups surgeons that use the product, believe further warnings are necessary.

Public Citizen petitioned the Food and Drug Administration (FDA) on Thursday to "immediately increase its warnings ... about the use of botulinum toxin" because of "serious adverse reactions, including deaths, linked to the drug."

The toxin is sold under the commercial names of Botox or Vistabel (Allergen Inc), Myobloc or Neurobloc (Solstice Neurosciences Inc.) and Dysport (Ipsen Ltd).

The FDA "has not issued any warnings to patients or doctors about the dangers of using the toxin," the group, founded by consumer campaigner and former presidential candidate Ralph Nader, said in a statement.

The botulinum toxin is a natural poison found in decomposing food that is 40 million times more powerful than cyanide.

When injected, tiny dosages of the toxin paralyze a muscle and prevent it from contracting for between four and six months -- ideal for temporarily eliminating facial wrinkles.

In its petition, Public Citizen notes that US authorities have approved the toxin for "a limited number of 'therapeutic' conditions, including uncontrollable neck and shoulder muscle contractions, crossed eyes, spasmodic blinking of the eyes and excessive underarm sweating.

"The only approved cosmetic use is for temporary smoothing of wrinkles between the eyebrows. Most cosmetic uses of botulinum toxin are unapproved," the group said.

In some cases, according to Public Citizen, the toxin "has spread to other parts of the body with serious consequences, such as paralysis of respiratory muscles and difficulty swallowing ... possibly leading to food or liquids entering the respiratory tract and lungs, causing aspiration pneumonia."

The group said that between November 1997 and December 2006 there were 16 deaths among the 658 reported cases of people "suffering adverse effects from injections of botulinum toxin."

The FDA data they used came "from voluntary reports, which have been estimated to account for only 10 percent of actual cases," the statement read.

The American Society for Dermatologic Surgery, a 5,000-member specialists' group, said in a statement Saturday that it supports the current labeling of Botox "for its intended use by trained physicians."

The group "believes that there is no data to support additional labelling warnings and therefore disagrees with the petition filed by Public Citizen," the statement read.

Allergen Inc. said that there "are no safety issues raised in the petition that are not already addressed in the labeling for Botox."

Since its approval "over a million people have been treated with Botox cosmetic," said Sef Kurstjen, Allergen's chief medical officer, in the statement.

"In its entire history, there has never been a single reported death where a casual link to Botox cosmetic was established."

by Frederic Garlan