A Feasibility Study Looking at the Use of Glibenclamide and metfoRmin Versus stAndard Care in gEstational diabeteS

Study Overview
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Brief Summary
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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.

Official Title
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A Feasibility Study Looking at the Use of Glibenclamide and metfoRmin Versus stAndard Care in gEstational diabeteS

Conditions
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Gestational Diabetes, Pregnancy

Intervention / Treatment
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* Drug: Glibenclamide
* Drug: Insulin


Participation Criteria
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Eligibility Criteria
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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.

Ages Eligible for Study
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Minimum Age: 16 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Current Standard Care<br>Insulin + Metformin | Drug: Insulin<br> <br> |
| Active Comparator: Treatment<br>Glibenclamide + Metformin | Drug: Glibenclamide<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of women willing to be randomised | Retention - proportion of women randomised who remain in the study to provide outcomes Adherence - proportion of clinicians who adhere to the treatment regimen(s) | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Glycaemic control | Safety - number of hypoglycaemic episodes needing treatment, any other adverse events | 2 weekly | 
| Patient satisfaction | assessed by visual analogue scale | 36-38 weeks gestation | 
| Clinical outcomes | Change in maternal weight between booking and 36 weeks | 36 weeks | 
| Clinical outcome | Mode and gestation of delivery. | 40 weeks | 
| Clinical Outcome | Birthweight centile (adjusted for sex and gestation at birth) | 40 weeks | 
| Clinical Outcome | Incidence of neonatal hypoglycaemia (defined as any of the following: blood glucose <2.6 mmol/l) in first 48hrs age, or given intravenous glucose or any other drug to increase blood glucose) | 2 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pregnancy, Gestational diabetes, Glycaemic control, Metformin