Labor Drug Assailed
Article Challenges Mag Sulfate Use
By Sandra G. Boodman
Washington Post Staff Writer
Tuesday, October 10, 2006; HE01
For the past 30 years or so, doctors have routinely given pregnant women intravenous infusions of magnesium sulfate to halt contractions that can lead to premature labor.Now a prominent physician-researcher is calling on his colleagues to stop using the drug for this purpose, saying that the treatment is unproven, ineffective and potentially deadly -- an artifact of an earlier era when the standard of care was based more on pronouncements than on clinical trials.
The drug, sold commercially as Epsom salts and known to doctors as mag sulfate, causes side effects that range from highly unpleasant to lethal: nausea, blurred vision, headache, profound lethargy, a burning sensation and, in rare cases, life-threatening pulmonary edema, in which the lungs fill with fluid."Why has it persisted? Tradition," said David Grimes, vice president of biomedical affairs for the nonprofit public health group Family Health International, who co-authored the provocative commentary "Time to Quit" in the current issue of the journal Obstetrics & Gynecology.Magnesium sulfate for preterm labor, Grimes said, is a "North American anomaly" confined to the United States and Canada whose continued use is predicated on "good hopes and good wishes rather than good data."
The American College of Obstetrics and Gynecology does not endorse use of the drug for this purpose, he noted.Four years ago a team of researchers from Australia reached similar conclusions in a report published by the Cochrane Collaboration, a respected international organization that evaluates scientific studies. The Australian team reviewed 23 clinical trials worldwide involving 2,000 women who had received the drug to quell contractions. They found that it did not reduce preterm labor and that more babies died when their mothers took the drug than in a control group where the mothers had not been given it.
Mag sulfate is typically administered between the 26th and 34th weeks of pregnancy for about 48 hours to stall contractions long enough to permit the injection of steroids, which speed fetal lung development.Grimes said he and Kavita Nanda wrote the commentary to promulgate the Cochrane findings among the nation's OB-GYNs. "The Cochrane review hasn't received wide visibility, so that's why we wanted to put this in a journal all OB-GYNs get."Continued use of the drug, Grimes and other critics of the practice say, exemplifies the slow pace of change in obstetrics, where it is hard to conduct clinical trials because the stakes are regarded as so high.
Doctors seeking to use a drug to stave off premature contractions that can trigger labor are better off using a calcium channel blocker such as nifedipine, which has been proven effective, Grimes said.Grimes and Nanda estimate that about 120,000 American women receive mag sulfate each year for premature contractions, and they say some evidence suggests it may be associated with 1,900 to 4,800 fetal deaths annually in the United States.
The latter figure is derived from a 1998 study in Obstetrics & Gynecology.But jettisoning a long-standing practice in obstetrics involves factors other than evidence, some doctors say.They note that the standard of care -- a benchmark of evidence in malpractice cases -- as well as patients' wishes and the desire to prevent a bad outcome such as premature birth -- all contribute to continued use of the drug.
"There is a current practice [to use the drug] that is the community standard," said Michael Gallagher, a specialist in maternal-fetal medicine, or high-risk pregnancy, who practices at Shady Grove Adventist and Holy Cross hospitals. Gallagher said he regards mag sulfate as a viable and safe option in some cases -- and not as an ineffective and potentially dangerous drug."Suppose we don't use it and a patient delivers," Gallagher said, noting that might violate the prevailing standard among OB-GYNs. "You find yourself in lonely places."
"Medical practice," he added, "doesn't move overnight." Nor, Gallagher said, does he think the evidence is "as cut and dried as Grimes says. This is his opinion."But, Gallagher said, he and many of his colleagues are careful to present the option of using the drug with plenty of caveats."We do a lot of 'we think' and 'maybes' and let women decide whether to take it," he noted.Not surprisingly, few refuse -- fearing the possibility of a bad outcome, he added.
For doctors, "there is pressure to use it from patients, as well as peer pressure" from other physicians, said Dallas OB-GYN Gary Cunningham, a professor at the University of Texas Southwestern Medical Center who noted that doctors are desperate to find something that works to stop preterm labor and prevent a premature birth with possibly devastating results."This drug has a powerful constituency," he said, adding that he is not part of it. The drug, he added, is an effective treatment for preeclampsia or eclampsia, pregnancy-induced hypertension that can be fatal to mothers and babies.
Before mag sulfate became widely used in the 1970s, Cunningham noted, doctors gave women intravenous alcohol to quiet contractions."All we got was a bunch of drunk patients who vomited and aspirated, and some died," he recalled. Before that, doctors used morphine, which was abandoned for similar reasons.Alessandro Ghidini said it took him years to persuade colleagues at Inova Alexandria Hospital to stop using mag sulfate after his arrival about a decade ago."This is a medicine that American doctors are very familiar with," said Ghidini, a maternal-fetal medicine specialist. "It took a long time" to convince doctors the evidence was lacking, he said.In their commentary, Grimes and Nanda wrote that the popularity of the drug has been reinforced by "pronouncements in prestigious medical journals or from famous medical institutions.
" They cite a 1999 review article in the New England Journal of Medicine that stated "magnesium sulfate is safe and has become the first-line treatment for preterm labor in North America."" 'Overgrazing' of ineffective and harmful practices on the 'medical commons' is a stubborn problem in obstetrics," they wrote.
Cunningham said he still vividly recalls the time years ago that he took the drug to see what female patients experienced."It was scary," he said. "You feel like you're burning up."
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