Researchers investigate new treatment options for gestational diabetes

A team of Israeli researchers have studied the use of metformin and glyburide in the treatment of gestational diabetes.
Glyburide, also known as glibenclamide in the UK, is a second-generation sulphonylurea used in the treatment of non-insulin dependent type 2 diabetes. It lowers blood sugars by stimulating the release of insulin from the pancreas.
The standard therapy for women with gestational diabetes in the UK, as provided in the National Institute for Health and Care Excellence (NICE) treatment guidelines, does not involve glibenclamide in first instance.
Women requiring drug treatment are pointed towards metformin, with or without the addition of insulin, as a first line treatment instead. Since 2015, NICE allows the use of glibenclamide as an alternative to metformin in some circumstances.
While the use of glibenclamide is considered as an adjunct therapy in NICE guidance, its use as first option in gestational diabetes with or without metformin is more prevalent – notably overseas.
Previous research suggested that the combination of glibenclamide and metformin might have a synergestic effect, since both medications act to improve blood sugars by different but complementary mechanisms.
In this new study of 100+ women with gestational diabetes, researchers compared the risks and benefits of glibenclamide and metformin as single therapies on the one hand, and in combination on the other hand. Insulin was also added in some cases.
In terms of improvements to blood glucose control, they found glibenclamide to be inferior to both insulin (when required) and metformin. This confirms what was previously found in a 2015 meta-analysis published in the BMJ, which reported that metformin tends to perform better.
Researchers did however note that using glibenclamide in combination with metformin reduced the need for insulin.
No adverse fetal outcomes, such as higher macrosomia (larger than normal birth weight) risks or neonatal hypoglycemia, were reported.
Overall, the findings indicate that a monotherapy with glibenclamide should not be used for the treatment of women with gestational diabetes if insulin or metformin is available.
But, glibenclamide could allow a higher efficacy rate when coupled with insulin in women who can’t achieve blood glucose targets and/or cannot tolerate metformin.