WASHINGTON -- The Food and Drug Administration sai yesterday that it would end its ban on women's participation in most drug safety tests and require companies to carry out analysis by sex in virtually all applications for new drugs.
The FDA commissioner, Dr. David A. Kessler, said that he would send rules to companies in the next few weeks "saying that women simply must be included and we are lifting the 16-year ban we have had on women in early drug trials."
Women have been excluded because it was feared that the fetus would be damaged if they became pregnant during tests. "We now believe that there are ways to protect the fetus and to include women in studies at the same time," said Dr. Kessler in an interview.
Dr. Ruth Merkatz, Dr. Kessler's special assistant on women's health, said that in the past as many as half of drug safety experiments excluded women. Even in those including women, the data were often not analyzed to see if the drugs affected women differently, thus risking health damage in women if side effects were not noticed.
She said the agency had drafted new rules intended to assure that women would be included in nearly all tests and that their numbers would be sufficient to tell differences in how men's and women's bodies reacted to a drug.
The chief effect of not having such data has been that drug doses for women were sometimes wrong, to the point that they made the drugs useless or worse, FDA officials say. For example, it was not known until recently that oral contraceptives could sometimes block the effects of other drugs or that other drugs could prevent contraceptives from being effective.
Many drugs act very differently in women's bodies. For example, antidepressants and tranquilizers are absorbed at a different rate by women than by men, meaning the doses for women should be different.
In one case it was found that an antidepressant drug caused more far more seizures in women because of different absorption patterns and that lower doses could be effective without causing seizures.
Dr. Kessler said that if researchers and companies did not
include enough women, "we reserve the right not to approve their applications."
He added that "it should never come to that," because including women was relatively easy and would not necessarily increase the number of people needed for tests, but rather the proportion of them that were women. That means drug companies' costs for the tests would not be significantly increased.
The Food and Drug Administration now receives more than 2,000 applications a year from companies or researchers who want to study drugs or have them approved for market. Since the issue of excluding women from studies began to be raised as a political issue, the agency says the proportion of studies it receives that include women has risen to about 60 percent.