Experts advising the Food and Drug Administration said Friday it should approve use of Depo-Provera, a drug that provides three months of birth control protection with each injection.
The FDA panel's recommendation was unanimous.The Fertility and Maternal Health Drugs Advisory Committee, which heard a day's worth of testimony from the public, the manufacturer and the government, reached its decision quickly once the testimony ended.
The drug, manufactured by the Upjohn Co., is approved for use in the United States to treat endometrial and renal cancers.
Because it is an approved drug, some doctors do prescribe it as a contraceptive. But that is outside the drug's labeled use, and such doctors open themselves to some legal liability.
The question before the FDA is whether the drug is scientifically linked to breast, liver or cervical cancer. The advisory panel's findings are not binding, but the FDA usually follows the advice of such panels.
An Upjohn vice president, Dr. Joann L. Data, told the committee that the company's studies found that one side effect of the drug is weight gain. She said generally the weight gain does not go beyond 15 pounds but occurs in 60 percent of the women using the drug and increases with time.
Depo-Provera, which is known generically as depot-medroxyprogesterone acetate, or DMPA, also has been the subject of legal controversy because it could be used for so-called "chemical castration" sentences that judges have considered imposing on sex offenders.
Since the late 1960s, the drug's use as a contraceptive in this country has bounced back and forth between approval and a ban, based largely on animal studies that suggest a link to cancers of the cervix, liver and breast.
More recent studies, though, have indicated that the link may not be as strong as previously believed.
Results of a study on breast cancer, conducted in Kenya, Mexico and Thailand, found no increased risk among women who used the drug for more than five years.
"Both our investigation and the New Zealand study provide some reassurance that women who have used DMPA for a long time and who initiated use many years previously are not at increased risk of breast cancer," the researchers wrote last October.