An independent academic center at Tufts University said yesterday that critics who blast the American pharmaceutical industry for developing “me-too” prescription drugs are wrong.

Me-too drugs, known in industry parlance as “follow-ons,” are pills that are similar to drugs already on the market and which treat the same disease. The biggest health markets - for treatments to lower cholesterol, control stomach acid or high-blood pressure, and reduce male impotence, for example - have attracted numerous follow-ons.

The Tufts Center for the Study of Drug Development, which relies on pharmaceutical and biotech grants to conduct much of its research, said in a report issued yesterday that follow-on drugs introduce market competition, which holds down prices and provides better treatment options for doctors and patients.

“Far from being redundant, follow-on drugs create therapeutic alternatives, which enable physicians to individualize patient treatment,” said Kenneth Kaitin, the center’s director.

The center studied 72 disease categories and found 235 examples of drugs approved by the Food and Drug Administration to treat those 72 markets since 1960. In the last seven years, many of these drugs were heavily marketed directly to consumers.

More than six anti-cholesterol drugs on the market, from Crestor to Zocor, are frequently advertised on television. The market for male sexual enhancements started with Pfizer Inc.‘s Viagra and now includes two other drugs, Cialis marketed by Eli Lilly and Co. and Levitra, which is sold by a partnership of GlaxoSmithKline and Bayer Pharmaceuticals Corp.

The Tufts study said anti-cholesterol drugs are 45 percent cheaper than they were in the early 1990s, and blood-pressure medications are 72 percent cheaper.

But industry critics say me-too drugs are a prime example of what has gone wrong in American healthcare. They say pharmaceutical companies are using scarce research dollars to chase huge markets, not hunt down genuinely novel cures.

And once new brand-name drugs come to the market, the companies use mass-market advertising to fuel consumer demand while reducing consumer interest in cheaper generics, critics say.

Dr. Arnold Relman, a Harvard Medical School professor emeritus who co-wrote a scathing critique of me-too drug development in the magazine New Republic two years ago, said there is no evidence that me-too drugs improve health or reduce costs.

“All you have to do is look at the pricing history of any drug on the market. It never goes down. It always goes up,” Relman said. “The companies go where the money is, and the money is in these big, me-too markets.”

The industry’s lobbying group, the Pharmaceutical Research and Manufacturers of America, lauded the study results.

“If the first drug doesn’t work for you, there is no such thing as a me-too drug,” said Wanda Moebius, PhRMA spokeswoman. “You have no other alternative than to find another drug that works for you. People aren’t one size fits all.”