The discovery that antidepressants may increase suicidal tendencies in children has prompted some lawmakers and physicians to ask if changes are needed to financial incentives given to drug makers for pediatric research.

The program, which rewards companies that conduct pediatric research with a six-month patent extension, started in 1997. It has resulted in more than 100 drugs being studied and has uncovered important information about how medicines work in youth.

For years, a drug used to control seizures and relieve pain in adults did not appear to work for very young children.

Then researchers found kids younger than five were clearing Pfizer Inc.‘s Neurontin from their bodies more quickly than they thought, so doses 30 percent higher were needed for the drug to work.

“I think all of us have been surprised” by that result and others showing how much children vary from adults in their reactions to medicines, said Dr. Dianne Murphy, director of pediatric therapeutics at the Food and Drug Administration.

In another study, an anesthetic called propofol used for sedating children in intensive care was shown to cause more deaths than another option.

About one-quarter of the time, studies have shown drugs were ineffective in children, were being used at the wrong dose or were linked to previously unknown risks, Murphy said.

Some worry that doctors do not get the results quickly enough. The FDA has resisted updating drug labels when studies fail to show effectiveness, arguing they might indicate a poorly designed study rather than an ineffective medicine.

Amid the antidepressant controversy, FDA officials said they were reconsidering that position.

Twelve out of 15 studies in children failed to prove various antidepressants worked. Many psychiatrists were unaware of those results until regulators disclosed them during their probe of possible ties to suicidal behavior. The drug labels do not reflect that information.

GOOD NEWS, BAD NEWS

“If you are going to give people the good news, you also have to give them the bad news,” Michigan Democrat Rep. Bart Stupak said at a congressional hearing on antidepressants.

The FDA posts summaries of pediatric research on its Web site, but some say it takes too long for findings to appear.

Some Democrats may try to modify the program when it is reconsidered in 2007. Stupak suggests delaying the patent extension until the drug label is updated to reflect study findings.

Pediatricians had lobbied for a requirement to update drug labels but faced opposition, said Dr. Ralph Kauffman, medical research director at Children’s Mercy Hospital in Kansas City.

Companies “can get the reward and never change the label. That is ... a weak point in the current law,” Kauffman said.

The push for pediatric testing grew out of frustration that decades of research involved mostly adults. Children’s bodies react differently to medicines than adults’ do, in part because kids break down drugs at various rates.

With hundreds of millions of dollars in extra sales possible from the patent extensions, information came pouring in to the FDA. Seventy-six changes to label instructions have been made as a result.

With Neurontin, “we relieved a lot of suffering by knowing the appropriate dose,” said Dr. Richard Gorman, a Baltimore pediatrician and chair of the American Academy of Pediatrics’ drugs committee.

Delaying patent extensions may discourage research because inconclusive studies may never prompt a label change, said Alan Goldhammer, an associate vice president at the industry group Pharmaceutical Research and Manufacturers of America.

“I would caution against changing something that is documented to be working,” Goldhammer said.