- The Washington Times - Friday, May 27, 2005

From combined dispatches

New York pharmaceutical giant Pfizer Inc. said yesterday it may change its product label warning for Viagra after reports possibly linking the drug to cases of vision loss in patients taking it to overcome impotence.

Pfizer is in talks with the Food and Drug Administration, which regulates U.S. prescription drugs, to update the Viagra label, the company said.

Viagra’s competitor, Cialis, made by Eli Lilly & Co., already has a similar warning on a label that was implemented 10 days ago, said Christine Van Marter, spokeswoman for the Indianapolis drug company.

The FDA has 43 reports of NAION, or non-arteritic anterior ischemic optic neuropathy, among the impotence drug users: 38 for Viagra and four for Cialis, said spokeswoman Kathleen Quinn.

Levitra, which is sold in the United States by GlaxoSmithKline PLC and Schering-Plough Corp., also had a patient report of vision loss.

“We continuously monitor the safety of our products and we will continue to work with all regulatory agencies as appropriate,” said Schering spokesman Matthew Scampoli.

At issue is sudden vision loss when blood flow to the optic nerve is blocked, a condition called NAION.

Ms. Quinn stressed that the agency has not determined that the drugs cause NAION.

NAION also is considered one of the most common causes of sudden vision loss in older Americans, and estimates suggest there are anywhere from 1,000 to 6,000 cases a year. Risk factors include diabetes and heart disease, two of the leading causes of impotence.

“We are working with the companies to ensure information about vision loss is available to doctors and patients,” Ms. Quinn said.

The reports are rare. More than 23 million men worldwide have used Viagra since it came on the market in 1998, Pfizer said.

More than 5 million men worldwide have used Cialis since it entered the market in February 2003, Mrs. Van Marter said.

Dr. Ira Sharlip, a San Francisco urologist who prescribes about 20 erectile disfunction drugs weekly, said Viagra and Cialis users should not panic about the new reports.

“If this is a real problem, then I think it should be investigated. But it’s all purely speculative at this point,” said Dr. Sharlip, spokesman for the American Urological Association, a Linthicum, Md., trade group.

Viagra and its competitors are drugs that revolutionized treatment of erectile dysfunction. They already come with serious warnings.

Previous reports have found that these drugs can cause a dramatic drop in blood pressure if mixed with nitroglycerin medication for heart problems, Dr. Sharlip said.

All three drugs also warn about temporary vision changes — seeing bluish tinges or having difficulty distinguishing between green and blue. The drugs apparently have a temporary effect on the retina, a different issue from NAION.

Pfizer shares dropped 55 cents yesterday on the New York Stock Exchange to $28.35.

Shares of Eli Lilly & Co., which makes Cialis, closed at $59.05, down 5 cents, also on the Big Board.

Glaxo’s U.S. shares rose 38 cents to $49.78 on the NYSE while Schering shares fell 11 cents to $19.67.

The new reports come at a time when federal regulators and the drug industry are facing criticism about what they do to ensure the safety of drugs already on the market. Pressure on the FDA to investigate reports of side effects has increased since Merck & Co. yanked pain reliever Vioxx from the market last year.

A lot of money is at stake. Impotence medications, the leader among “lifestyle drugs,” grossed $1.36 billion in U.S. sales last year, up 8 percent from 2003 sales of $1.26 billion, according to the latest information from IMS Health Inc., a Fairfield, Conn., pharmaceutical information and consulting company.

Pfizer said in its most recent quarterly filing with the Securities and Exchange Commission that sales of Viagra rose 5 percent — to $438 million — in the first quarter of the year.

Staff writer Marguerite Higgins contributed to this report.

LOAD COMMENTS ()

 

Click to Read More

Click to Hide