You cant just go from 900mg of Neurontin to another drug. In this case Lyrica.
50mg-100mg a day or you will experience withdrawal. If Lyrica is your choice then stay on Neurontin until you gradually get off it and then hit a higher dose of Lyrica.
Good Luck

Malawigirl has stated just above:
Anyone discontinuing gabapentin, should be tapered by the doctor and supervised carefully. The higher the dose, and the longer one has been using it, should have a longer taper. But there is not much information on the net giving strict taper schedules, so one must be sure their doctor is informed on how to do this. Some people come down 100mg a week. But that is only an average. It may vary from person to person.

Mrs D, my doc wants me to come off 2400mg per day in a week, at the rate of 300mg per day- I am in day 3 and it isn't pleasant- I am going to maintain this level for a few more days- I have loads of gabapentin so willtake my time. My GP is so young she must just be out of med school and had to look up a book to see if switch was possible! I dont have a lot of confidence in her experience.

I think that is too fast.

Most doctors, even for opiate or benzo withdrawal go too fast as well.

I think you can slow that up, so you will feel better. Different people react in different ways.

Like SSRI drugs, the Big Pharma Dudes, never really gave doctors or patients withdrawal or discontinuance information!

This is all I could find:
http://www.ncbi.nlm.nih.gov/pubmed/15898970

Suggesting a SLOW taper like with Benzos.

My GP is so young she must just be out of med school and had to look up a book to see if switch was possible! I dont have a lot of confidence in her experience.[/QUOTE]

Hi mawlawigirl, I sometimes wonder what is worse someone new or someone who has been around a long time. Some docs with a lot of experience don't want to hear anything we have to say or suggest. Honestly, I give a doctor credit when they say I don't know the answer to that but I will get back to you. It shows their honest
I have been through having to wean off some meds to be placed on others. It is really tough. I feel bad for you. Hang in there it ended up being worth it for me. I don't think I realized just how bad this got until I was weaning off.

I think a doctor who looks things up.... it far "better" than one who won't.(because of ego or arrogance).