Is your 1800 a total daily amount or a per dose amount?
Total daily amounts can max up to 3600 or, in my case, 4200mgs/day.
If your 1800 is a daily amount, it is a 'starter dose'.
Wait 2-4 weeks on one level, before upping your dosage.
Do not try other drugs indiscriminately, until you've given any one med a fair chance to discover the proper dosage, or unless you are getting severe bad side effects.
Don't let the stories scare you. We're all different, that's why there are over 75 different meds now Rx'd for PN. You can't try them all, but you've got to give the ones you do try, a fair chance to work.
BTW- Neurontin works best in conjunction with a pain med, as ot is not a pain killer, but a symptom reducer. It is an anti-spasm med that works on the nerve receptors that are mis-firing and your brain interprets with all the symptoms. If used in conjunction with a pain killer, pain levels can be reduced better than if only one med is used.
The two work better than either one, alone.