Hello, Thank you for your query. I understand your concerns. You are right in suspecting that your fainting episodes could be due to your medication. From what you have written, I feel it could be your insulin that is causing you to have hypoglycemic episodes (low blood glucose episodes) in the night. Did you measure your blood glucose levels just after the episode? Was it too low? If it was low, then it means that either the insulin that you are taking at bedtime and with evening meals is too high or that you are eating very less at night. One way of dealing with this problem is by reducing your insulin dose by 2-4 units and checking your 3 AM blood glucose and fasting blood glucose levels. If these are still low, you can reduce your insulin further. It is better you see your doctor for this titration. The other cause that can contribute your loss of consciousness is that may be your BP is going too low at night. This is a bit unlikely though with the medications that you mentioned but is still a possibility. Did you get your blood pressure checked recently? Are you taking all your BP tablets at night? If you are taking all of them at night, you could take a few in the morning and few at night (your BP lowering medicines are Lisinopril, Isosorbide mononitrate and Metoprolol) I would advise you to see your doctor as soon as possible as you should not be losing consciousness. There could be other causes too – cardiac arrhythmias (irregular heart beat), epilepsy etc. I wish you a speedy recovery. I hope this answer has been helpful to you. Regards Dr Sunita Sayammagaru