RENO, NEV. — Glyburide may successfully control gestational diabetes in all but about 20% of patients, and a failed trial of glyburide appears to cause no long-term harm, Meredith Rochon, M.D., of the department of obstetrics, gynecology, and reproductive science at Mount Sinai School of Medicine, New York, and colleagues reported.
Glyburide treatment has been shown to be effective and safe for gestational diabetes.
The investigators reviewed the records of all patients with class A2 gestational diabetes treated with glyburide at a diabetes clinic over a period of 2 years to ensure that there were no adverse effects when the treatment failed.
The study found no reason to avoid using glyburide instead of insulin as first-line therapy, the researchers wrote in a poster presented at the annual meeting of the Society for Maternal-Fetal Medicine.
Of 83 patients identified, 18 (22%) were patients who underwent a trial of glyburide but failed to reach the target of fasting and postprandial-glucose levels of 60-90 mg/dL and 120 mg/dL, respectively, even when treated with a dose of 20 mg daily. Consequently, those patients were switched to insulin.
Despite their initial lack of blood glucose control, the pregnancy outcomes in the patients who failed treatment—including birth weight, mode of delivery, and incidence of macrosomia—were no different from those who were successfully managed on glyburide.
The sole difference in outcome was in the patients who were successfully treated with glyburide. Those patients had more neonates who required admission to the neonatal intensive care unit (NICU) than did the women who had been switched to insulin (35% vs. 11%).
The most common reason for the admission was hypoglycemia (10 of 23 admissions).
In an interview, Dr. Rochon said the finding was a surprise and something of a mystery, since glyburide does not cross the placenta, and previous studies have not noted this potential association.
The hypoglycemia was not considered by the investigators to be a serious adverse effect because it was transient in all cases. However, if it proves to be true that glyburide treatment does produce a higher rate of hypoglycemic neonates who need NICU admission, it may have significant cost implications, Dr. Rochon said.
The mean length of stay was 8 days for all the babies that were admitted to the NICU and 4 days for those admitted with hypoglycemia.