Aug. 9 (Bloomberg) -- Pfizer Inc.'s best-selling cholesterol medicine Lipitor cuts the risk of stroke recurrence in patients without heart disease, doctors say.

Patients taking the highest dose of Lipitor had a 16 percent lower incidence of suffering a second stroke compared with those given a placebo, or inactive pill, according to a study in tomorrow's New England Journal of Medicine. The report confirms results presented in May at the European Stroke Conference in Brussels.

Publication of the finding may help New York-based Pfizer, the world's largest pharmaceutical company, shore up demand for Lipitor, which has been losing sales to cheaper, generic copies of Merck & Co.'s rival Zocor medicine. Doctors should give Lipitor to stroke patients, said Michael Welch, the study's lead researcher.

``We hope to see this established as an added treatment to the standard care of patients who had a stroke,'' said Welch, president of the Rosalind Franklin University of Medicine and Science in Chicago, in a telephone interview yesterday.

One investment strategist, Les Funtleyder of Miller Tabak & Co. in New York, expressed skepticism that the journal report will spur physicians to prescribe the Pfizer drug.

Doctors may assume that cheaper medicines in the same class -- called statins -- have the same effect, Funtleyder said.

`Class Effect'

``Doctors may just hope for the class effect unless Pfizer did a head-to-head study that showed Lipitor was significantly better than everything else in the statin class for reducing recurrent stroke,'' Funtleyder said in a telephone interview yesterday.

Pfizer shares fell by 1 cent to $26.15 at 4:24 p.m. today in New York Stock Exchange composite trading. The shares were little changed in the year before today.

Cheaper copies of the Zocor cholesterol pill captured 12 percent of the U.S. market as of July 21, four weeks after Merck's patent expired on June 23, according to data compiled by IMS Health Inc., a Fairfield, Connecticut-based research company. More than 25,000 Lipitor prescriptions were switched to generic Zocor during that time, the data show.

The new study of 4,731 patients also found that people taking Lipitor had a 35 percent reduction in their risk of non- fatal heart attacks and cardiac death compared with those given the placebo, the doctors wrote.

Pfizer sponsored the study, called Stroke Prevention by Aggressive Reduction of Cholesterol Levels. The work was the first to show Lipitor reduces the risk of a second stroke in patients without a history of heart disease, said Rochelle Chaiken, a Pfizer vice president and medical group leader, in a telephone interview yesterday.

`Very Exciting'

``These data are actually very exciting for someone who takes care of people at risk of stroke,'' Chaiken said. ``We now have a new therapy for people with a previous stroke.''

Strokes can lead to speech impairment, paralysis and loss of memory, and are the third-biggest killer in the U.S., after heart disease and cancer, according to the National Stroke Association, based in Centennial, Colorado. As many as 300,000 of the 750,000 strokes in the U.S. each year are repeat attacks.

Earlier studies have shown that Lipitor can help cut the recurrence of strokes by about a third in people with a history of coronary heart disease.

Pfizer has studied Lipitor in more than 400 trials to find new indications for the drug and persuade doctors that the medicine is superior to other cholesterol pills. The company has tried out Lipitor in patients with diabetes, Alzheimer's disease and a history of heart attack, Pfizer spokeswoman Shreya Prudlo said in a telephone interview yesterday.

Blood Thinners

To treat strokes, doctors now rely on medicines that prevent blood clots. These drugs include Plavix, made by New York-based Bristol-Myers Squibb Co. and Paris-based Sanofi- Aventis SA. Physicians also encourage patients to make lifestyle changes, including diet alterations and quitting smoking.

Prudlo said today the company doesn't know how many stroke patients are currently taking Lipitor. In the U.S., the drug is approved for use in reducing heart attack and stroke risk in people without evident heart disease who have multiple risk factors for it. The drug also is used in patients with type 2 diabetes, which raises cardiovascular vulnerability.

To contact the reporter on this story: Nicole Ostrow in New York at nostrow@bloomberg.net.

Last Updated: August 9, 2006 17:00 EDT