This trial has been completed.

Conditions pregnancy, gestational diabetes
Treatments glibenclamide, insulin
Phase phase 3
Sponsor University of Edinburgh
Collaborator Chief Scientist Office of the Scottish Government
Start date July 2014
End date October 2015
Trial size 23 participants
Trial identifier NCT02080377, 2013-004706-25, GRACES


The aim of this open label feasibility study is to determine recruitment rates to a randomised trial of glibenclamide compared with insulin (both in addition to maximum tolerated metformin) for the treatment of Gestational Diabetes Mellitus (GDM). This feasibility trial will inform the design of a future substantive multicentre trial to test the hypothesis that combination therapy with glibenclamide and metformin could reduce the number of pregnant women with GDM who require insulin and would be superior to metformin and insulin in terms of acceptability and cost effectiveness.

Women with GDM who have "failed" monotherapy with metformin will be recruited and randomised to either receive glibenclamide (test arm) or standard care with insulin, both in addition to their maximum tolerated dose of metformin. Patients will be recruited from three of the antenatal clinics.

This is a feasibility study in preparation for a large multicentre randomised trial to test the hypothesis that the addition of glibenclamide to metformin (combination therapy) could reduce the number of pregnant women with gestational diabetes mellitus requiring insulin, without compromising glycaemic control or other clinical outcomes. The investigators hypothesise that combination therapy with metformin and glibenclamide is likely to be preferable to metformin and insulin in terms of acceptability and cost.

United States No locations recruiting
Other countries No locations recruiting

Study Design

Allocation randomized
Endpoint classification safety/efficacy study
Intervention model single group assignment
Masking open label
Primary purpose treatment
(Active Comparator)
Insulin + Metformin
(Active Comparator)
Glibenclamide + Metformin

Primary Outcomes

Number of women willing to be randomised
time frame: 2 years

Secondary Outcomes

Glycaemic control
time frame: 2 weekly
Patient satisfaction
time frame: 36-38 weeks gestation
Clinical outcomes
time frame: 36 weeks
Clinical outcome
time frame: 40 weeks
Clinical Outcome
time frame: 40 weeks
Clinical Outcome
time frame: 2 days

Eligibility Criteria

Female participants from 16 years up to 50 years old.

Inclusion Criteria: - Pregnant women diagnosed with gestational diabetes who fail to achieve "adequate glycaemic control" on maximum tolerated dose metformin - Inadequate glycaemic control is defined according to the SIGN 116 guidelines. Exclusion Criteria: - Pregnant women requiring insulin prior to 20 weeks gestation or after 36 weeks gestation. - Pregnant women not taking at least 500mg metformin daily. - Patients with suspected Type 1 diabetes mellitus presenting in pregnancy. - Women with allergies to either glibenclamide or insulin or any of their excipients. - Women with any contraindications to sulfonylurea therapy. - Women unable to give informed consent.

Additional Information

Official title A Feasibility Study Looking at the Use of Glibenclamide and metfoRmin Versus stAndard Care in gEstational diabeteS
Principal investigator Jane E Norman, MD
Trial information was received from ClinicalTrials.gov and was last updated in December 2016.
Information provided to ClinicalTrials.gov by University of Edinburgh.