Carbamazepine is pretty toxic too. It has a long history going back decades for trigeminal neuralgia. But it has side effects on the bone marrow and electrolytes (hyponatremia). You can look it up on Google for more details. There is a poster here from a few years ago on Medications forum who was on this for a long time, and removed without a taper by his doctor, who had a horrific time with this drug.
https://www.neurotalk.org/members/18957.html
if you read some of his early posts you'll see what he went thru.

If the researchers can come up with sodium channel blocker, that is selective and spares the heart, that would be a good thing.
But it takes several years for the real side effects to become obvious sometimes, so who knows?

This is the poster who had the lidocaine infusions:
https://www.neurotalk.org/members/24499.html

Read her posts and see if your doctor would agree to those. Some of our RSD posters have had lidocaine infusions too.