I occasionally increase by an extra 300mg at bed time if needed, but so far have always been able to drop back to 1200mg daily.
When I was first rx'd Gabapentin
pills) my instructions were to start at 300mg
daily, then waiting 5 days to a week between increases, and up my dose by 300mg per day till my pain, tingling, etc was under control, adding or subtracting 300mg daily to 'balance' to my correct dosage.
I was free to increase as needed up to a maximum of 3600mg daily.