Some doctors and patients have expressed concerns that the drugs may not be equivalent in their effects, although generic drugs are chemically equivalent in terms of active ingredients, the study's authors said.
In Wednesday's issue of the Journal of the American Medical Association, Dr. Aaron Kesselheim of Brigham and Women's Hospital and Harvard Medical School in Boston and his colleagues combined the results of 30 studies done since 1984 that compared nine subclasses of cardiovascular medications, 81 per cent of which were randomized controlled trials.
"The studies in our sample concluded that generic and brand-name cardiovascular drugs are similar in nearly all clinical outcomes," the researchers concluded.
Brand-name prescription drugs are sold at high prices after approval by the U.S. Food and Drug Administration and while under patent protection, the study's authors said. Brand-name cardiovascular drugs may cost as much as a few dollars per pill while generics may be as little as a few cents a pill, Kesselheim added.
"If a patient is prescribed a generic drug because that's what's appropriate for their condition, then they should feel confident taking that drug. And physicians themselves should also feel confident prescribing generic drugs where appropriate," Kesselheim said in a telephone interview.
Of 43 editorials and commentaries reviewed, 23 or 53 per cent expressed a negative view of the interchangeability of generic drugs compared with 12 (28 per cent) that encouraged substitution of generic drugs, with the remaining eight not reaching a conclusion, Kesselheim and his colleagues said.
As for why, commentaries may be more likely to highlight doctors' concerns based on anecdotal experience, and the conclusion of the editorial writers could be skewed by financial relationships, the team said in noting that nearly half of the editorials and commentaries did not identify sources of funding.
Generic medications account for 65 per cent of all prescriptions dispensed in the U.S. and less than 21 per cent of money spent on prescriptions, according to IMS Health, a company that tracks prescription drug sales.
"The contention that brand-name medicines drive up the cost of health care is fatally flawed," Ken Johnson, senior vice-president of the Pharmaceutical Research and Manufacturers of America, or PhRMA, which represents brand-name drug makers, said in a statement released in response to the study.
"Without today's innovative brand-name drugs to legally copy, there would be no generic drug industry," he said.
The study's authors reported no financial disclosures.