GLIMIPREX is a combination of GLIMMIPRIDE and METFORMIN
GLIMMIPRIDE is an anti-diabetic drug (sulfonylurea-type) used along with a proper diet and exercise program to control high blood sugar. It is used in patients with type 2 diabetes
(non-insulin-dependent diabetes). It works by stimulating the release of your body's natural insulin.
GLIMMIPRIDE doesn't cause any damage to pancreas
As far as fasting blood sugar levels are concerned,the values in your father reports are normal.There is no point in bringing the blood sugar levels to below non diabetic range,as it can lead to hypoglycemic attacks and cause problem to the patient.
I don't think there is any need to switch over to any other medicines as these levels are normal.