SAN ANTONIO, Oct 19, 2004 (United Press International via COMTEX) -- For 20 years, women with lupus have been told they cannot use contraceptive pills because hormones in the pills could cause disease flare-ups, but now it appears that advice -- which was based on some tests in animals -- might have been wrong.

Two studies presented at the annual meeting of the American College of Rheumatology found no differences in the disease in women on contraceptive pills vs. those who use intra-uterine devices.

"We may have been giving our patients the wrong advice about birth control pills for the past 20 years," said Dr. Michelle Petri, a professor of medicine at Johns Hopkins University in Baltimore.

In a study performed in the United States that enrolled 183 women, and another performed in Mexico involving 162 women, doctors reported no differences in safety issues among women on pills or other means of birth control.

Petri said for many years, based mainly on animal models of disease, doctors treating women with lupus have warned them against using contraceptive pills for fear the hormone-containing medications would exacerbate their condition.

That is not what Petri found, however, in her year-long investigation.

"We saw no differences in disease relapses between patients on the contraceptive pills or on placebo," she said.

Petri's team found that about one-third of women with lupus are susceptible to blood clots and those women should not be taking contraceptive pills. Women with anti-phospholipid antibodies -- who are prone to abnormal clotting -- were excluded from the trial. Women with that condition should avoid taking birth-control pills, Petri said, adding that rheumatologists routinely test lupus patients for these antibodies.

In a second study, F. Jorge Sanchez-Guerrero, professor of immunology/rheumatology, at Instituto Nacional de Ciencias Medicas y Nutricion in Mexico City, compared outcomes of women suffering from lupus who took different forms of birth control pills or used intra-uterine devices. His team, likewise, found no increases in disease flare-ups among the three groups of patients.

Sanchez-Guerrero randomized his lupus patients to receive one of two types of birth control pills and compared the groups, both to each other and to a selection of women who used intra-uterine devices for birth control.

The use of combined oral contraceptives, progestin-only oral contraceptives -- known as the minipill -- and copper intra-uterine devices appear to produce the same level of risk for disease activity and flares, he said.

Lupus causes skin rash, joint pain and kidney disease, but women -- who are diagnosed far more often with the disease than men -- can have normal fertility, Petri said. The worry is that pregnancy among these women can cause disease flare-ups and can be dangerous for both the mother woman and her child, which may be born early or may miscarry.

"We are disproving old myths about lupus therapy," said Ellen Ginzler, professor of medicine and chief of rheumatology at the State University of New York-Downstate Medical Center in Brooklyn.

About 500,000 to 2 million people in North America suffer from lupus, said Dr. Jill Buyon, professor of medicine at New York University and a co-author of Petri's study.

Ginzler noted several million more individuals may suffer from lupus-like diseases that have some of the symptoms of lupus but not the entire spectrum of conditions.

"I believe these studies will change clinical practice," Ginzler said. "However, old ideas die hard."

She suggested academic physicians probably would accept the results of the trials, while primary care physicians might be slower to change their treatment habits.

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Ed Susman covers medical issues for UPI Science News. E-mail sciencemail@upi.com

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