I don't think there is any interaction between neurontin and lamictal. Nope, I checked. So it shouldn't affect your dosing at all. It's ok to take 2 drugs from the same class. Sometimes they affect each other but they usually don't. Those two are really different with side effect profiles so that would also help them not affect each other. Depakote and lamictal require lamictal dose to be lowered b/c depakote raises the levels but that's the only interaction between anti-convulsants I can think of (and I always took them in pairs b/c I was always on Depakote when I was motoring through those drugs).

Propanolol is Inderal which I think used to be a really commonly used blood pressure med and then newer ones came out and it doesn't seem to be used nearly as often now. I'm not sure why. I took it for tremors for a long time and never had trouble with it and I usually have a really low BP so have to be careful with meds that lower that. I also remember my grandma being on it. Which means it's at least 25 years old which may be why it's not in favor so much now.