dear sir i understand your concern.the blood sugar 410 is very bad and this will make your body to undergo many changes,so once you starting taking insulin this changes will become coming to normal again so you will feel some weakness and dizzy also some time .in my opinion use tab metformin 500 twice daily along with insulin than glimipride .you cane use glimipride when you stop using insulin. glimipride is not advisable in beginning stage as your pancreas will be in a phase of glucotoxicity and lipotoxicity....discuss with your doc for change over of glimipride to metfromin until sugars become normal.....