Seven in 10 physicians are more worried about the safety of drugs they prescribe after high-profile scares involving several medicines such as the withdrawal of arthritis pill Vioxx, a survey said on Thursday.

Sixty-eight percent of physicians would prefer prescribing a drug that has been on the market at least 10 years, even if costs among the possible medication options were equal. One third feel that new or recently approved prescription drugs are less safe than drugs on the market for a decade or more, according to the survey.

Medco Health Solutions Inc., the large U.S. pharmacy benefits manager, released the study, which was conducted by Forrester Research.

"With heightened awareness of that safety issue, I think physicians are struggling with that risk-reward trade off," said Robert Epstein, Medco's chief medical officer. "There's just been an ongoing flurry of publicity surrounding the safety of medicines, and I think people are becoming more sensitive to that issue."

In another finding, nearly 20 percent of physicians said they believe generic drugs are less safe than brand-name medications. Twenty-seven percent said they believe generic medications will cause more side effects than brands.

Generics are lower-cost copies of brand-name medicines that have lost patent protection, and they are substituted at pharmacies for their brand-name counterparts.

Despite U.S. regulations that require generics of a drug to be bioequivalent to its branded counterpart, one quarter of the physicians surveyed said they do not believe generic medications to be chemically identical to the brands, Medco said. More than 8 percent of physicians said they were unsure.

"These survey results underscore the need to redouble our educational outreach efforts to physicians concerning generics," Epstein said in a statement accompanying the survey's release.

Medco has a financial stake in greater generic use. It has said it derives more than half of its profits from delivering generics to patients by mail delivery.

The survey involved 3,200 Americans, including 300 practicing physicians as well as consumers, pharmacists and health benefit administrators. It was conducted during the first quarter.

The survey followed Merck & Co.'s Vioxx withdrawal in September 2004, after a clinical trial showed it doubled the risk of heart attack and stroke after 18 months' use. Another recent concern involved worries that popular anti-depressants increased suicide risks among children.

The survey also found 55 percent of consumers indicated they were more concerned about the safety of the medications they take. Sixty-two percent of pharmacists said they were more concerned about the safety of the drugs they dispense.