Keep in mind that neurontin is off-label use

yet approved for and paid for by insurance company pharmacy plans. Very, Very similar to that of IVIG.
The difference is that IVIG – one brand only, has been approved for use treating CIDP [just a few months ago]….all other brands are still ‘off-label’ uses. GBS is assumed to be a short term use of this treatment and isn’t considered an issue. IVIG use has been ‘off-label’ for decades really. Because of this, there is little incentive for manufacturers to conduct clinical trials – and medicare is too much of a hassle for THEM to deal with unless forced.
Neurontin manufacturers made some very strong and unfounded claims in selling this drugs’ use for nerve pain [over 5 years ago]. Tho it is approved now for post-herpetic neuralgia and diabetic neuropathies specifically, it’s not officially approved for other nerve pains. Tho many here are benefitting from the use.
The first claims of neurontin effectiveness were printed in their ‘prescribing information sheets’. Approx effectivness was based on ‘anecdotal’ reports from 200 individuals. Yes, that’s science for you.
Sure wish it were different.