This question could be way off base , but here goes....is it possible that small fiber neuropathy could be induced by the initiation of a metformin/glyburide regimen ? I have been to the end of the web and back and found nothing for certain. My glucose and other lipids dropped like a rock once I started my anti-hyperglycemic treatment , within days I developed a fulminate sfn. Very suspicious....thnx Tom

but read page 18 of Glucovance's prescribing info...It discusses a notable drop in B-12 numbers...
http://packageinserts.bms.com/pi/pi_glucovance.pdf

Hope this helps.... - j

1) metformin may induce acidosis. This then would give symptoms, paresthesias.
For example I developed a hideous vertigo --irritation of my left ear nerve, while using metformin for insulin resistance. The drug itself was great for a while, then bingo...I became unable to drive or even walk. It took 6mos or more to get my life back, and I quit the metformin immediately suspecting it.
You can have a renal panel done to see if you have a problem there.

2) the other drug in that combo is glyburide, which if you are allergic to sulfa drugs, may give some systemic reactions. But I would think you would have rashes first to warn you of it.

Sometimes using oral agents gives low blood sugar. And low blood sugar attacks often mimic some PN symptoms. Numbness tingling. If you have a meter...I'd do it frequently ..in a journal. Also if your symptoms come and go, I'd look to episodes of hypoglycemia.

For what it is worth, I had normal fasting glucoses before the metformin.
averaging about 90 to 100. My doctor thought the metformin was making low
blood sugars at some times of the day, leading to the vertigo. But then I had some anion gap abnormalities with my kidney testing...so that may have contributed.

So yes, I think it is possible. But it may not be the only factor. It might be additive with your diabetes.