Cites fatal cardiac events: FDA issues warning against domperidone; Drug is used off label as lactation enhancer.(News)

Breast-feeding women should not take the dopamine antagonist domperidone to induce or increase lactation, because the drug may put them at risk of developing a fatal cardiac arrhythmia, the Food and Drug Administration has warned.

Domperidone (Motilium) is a gastric motility agent widely used in Canada, New Zealand, Germany, Australia, Mexico, and South Africa to treat gastric reflux and nausea. The drug also increases prolactin production. Although unavailable in the United States and not approved for lactation induction in any country, domperidone is being used off label as a galactagogue, the FDA said. Internet sites that support breast-feeding promote the drug heavily; many of these sites also give readers tips about how to procure it in oral form.

In a talk paper issued last month, the FDA said that in other countries, intravenous administration of high doses of domperidone has been associated with cardiac problems, including irregular heartbeat and, in a few cases, fatal ventricular arrhythmia. Many of the deaths occurred in the mid-1980s, after which the intravenous form of the drug was withdrawn in Great Britain, said Gerald G. Briggs, B. Pharm., pharmacist clinical specialist, Women's Hospital, Long Beach (Calif.) Memorial Medical Center.

"When you see that kind of adverse effect in high IV doses, it's a cause for concern," Mr. Briggs said.

Serious adverse events with the oral form in the recommended dosage (10 mg, three to four times a day) are probably rare, but there is a possibility of toxicity in women who take additional doses or who metabolize the drug poorly, he said.

He added that nursing babies whose mothers take domperidone in the prescribed dosage are probably not at risk for adverse events.

Domperidone is listed as a drug "usually compatible with breast-feeding" in the American Academy of Pediatrics' 2001 policy statement. "The Transfer of Drugs and Other Chemicals Into Human Milk." Web sites supporting the drug's use are incorrect in touting the listing as an official endorsement of domperidone's safety, said Dr. Richard Gorman, chair of the AAP's Committee on Drugs.